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Chapter 3. Lead and Lead compounds

3.1 Lead Overview

• 3.1.2 Potential Health and Environmental Impacts of Lead
• 3.1.3 Use and Functionality

3.2 Lead Use Identification and Prioritization

• 3.2.1 Use Identification
• 3.2.2 Use Prioritization

3.3 Lead Alternatives Identification and Prioritization

• 3.3.1 Alternatives Associated with Ammunition for Shooting Ranges
• 3.3.2 Alternatives Associated with Wheel Weights
• 3.3.3 Alternatives Associated with Fishing Sinkers
• 3.3.4 Alternatives Associated with Heat Stabilizers for PVC wires and cable coatings

3.4 Lead Alternatives Assessment

• 3.4.1 Alternatives Assessment for Ammunitions for Shooting Ranges
• 3.4.2 Alternative Assessments for Wheels Weights
• 3.4.3 Alternatives Assessment for Fishing Sinkers
• 3.4.4 Alternatives Assessment for Heat Stabilizers for PVC Wire and Cable Coatings

3.5 Summary and Conclusions

References

3.1 Lead Overview

Characteristics of Lead

Lead is a natural, bluish-gray metal. The chemical formula for lead is Pb, and its atomic weight is 207.2 g/mol. The Chemical Abstract Series number for lead is 7439-92-1. (National Institute for Occupational Safety and Health 2004) The following table provides a summary for key chemical and physical characteristics for lead.

See Table 3.1.1 Lead Summary Table

Manufacturers use lead in the form of a metal for many different products. Lead possesses the general physical properties of other metals as a conductor of electricity and heat. Lead has low melting temperature (327° C) and extreme malleability, which enables the easy casting, shaping, and joining of lead products. Lead is relatively abundant in the earth, and has a fairly low price when compared with other non-ferrous metals. Lead can be recycled as a secondary raw material from lead-acid batteries and other lead products (Thornton, et al. 2001).

The high density of lead is desirable for several product categories including weighting applications, and shielding against sound, vibration, and radiation. However, lead has very low tensile strength which precludes its use for applications that require even moderate strength. Creep is the slow plastic deformation of materials under a constant stress. Lead is subject to creep at normal temperatures because its melting temperature is relatively low (Thornton, et al. 2001).

Lead is commonly used in various alloys which offer physical properties different than elemental lead. For example, the strength and creep resistance for lead can be improved with the small additions of other metals (e.g. copper) to form alloys with more desirable mechanical properties.

Lead compounds have different physical properties than elemental lead, and are used for various products. The NLM HSDB lists over 120 lead compounds. The major lead compounds used in commerce are lead oxide (PbO), lead tetraoxide (Pb3O4), basic lead carbonate (white lead), tribasic lead sulfate, and dibasic lead phthalate. For example, the reactions of lead oxide in dilute sulfuric acid are fundamental to the operation of a lead-acid battery.

3.1.2 Potential Health and Environmental Impacts of Lead

Summary

Lead is used in the manufacture of batteries, metal products, cables, ceramic glazes, and other various products. Exposure to lead can occur from breathing contaminated workplace air or house dust or ingesting lead-based paint chips or contaminated dirt. Lead is a very toxic element, causing a variety of effects at low dose levels. Brain damage, kidney damage, and gastrointestinal distress are seen from acute (short-term) exposure to high levels of lead in humans. Chronic (long-term) exposure to lead in humans results in effects on the blood, central nervous system (CNS), blood
pressure, kidneys, and Vitamin D metabolism. Children are particularly sensitive to the chronic effects of lead, with slowed cognitive development, reduced growth and other effects reported. Reproductive effects, such as decreased sperm count and spontaneous abortions, have been
associated with high lead exposure. The developing fetus is at particular risk from maternal lead exposure, with low birth weight and slowed postnatal neurobehavioral development noted. Human studies are inconclusive regarding lead exposure and cancer.

Hazards

Human exposure to lead occurs through a combination of inhalation and oral exposure, while dermal absorption of inorganic lead compounds is reported to be much less significant than absorption by inhalation or oral routes. Inhalation generally contributes a greater proportion of the
dose for occupationally exposed groups, and the oral route generally contributes a greater proportion of the dose for the general population. The effects of lead are the same regardless of the route of exposure (inhalation or oral) and are correlated with internal exposure, as blood lead levels.
For this reason, this report will not discuss the exposure in terms of route but will present it in terms of blood lead levels.

Acute (Short-Term) Health Effects

Death from lead poisoning is likely to occur in children who have blood lead levels greater than 125 μg/dL and brain and kidney damage have been reported at blood lead levels of approximately 100 μg/dL in adults and 80 μg/dL in children. Gastrointestinal symptoms, such as colic, have also been noted in acute exposures at blood lead levels of approximately 60 μg/dL in adults and children. Short-term (acute) animal tests in rats have shown lead to have moderate to high acute toxicity. (Agency for Toxics Substances and Disease registry (ATSDR) 1999). Effects on glomeral filtration, neurodevelopment, and blood pressure are evident are blood lead levels below 10 μg/dL. The most sensitive targets for the toxic effects of lead are the kidneys and the hematological, cardiovascular, and nervous systems. Because of the multi-modes of action of lead in biological systems, lead could potentially affect any system or organ in the body (ATSDR 2005).

Chronic (Long-Term) Health Effects

Non-cancer Effects
Chronic exposure to lead in humans can affect the blood. Anemia has been reported in adults at blood lead levels of 50 to 80 μg/dL, and in children at blood lead levels of 40 to 70 μg/dL. Lead also affects the nervous system. Neurological symptoms have been reported in workers with blood
lead levels of 40 to 60 μg/dL, and slowed nerve conduction in peripheral nerves in adults occurs at blood lead levels of 30 to 40 μg/dL. Children are particularly sensitive to the neurotoxic effects of lead. There is evidence that blood lead levels of 10 to 30 μg/dL, or lower, may affect the hearing threshold and growth and development in children (ATSDR 1999). Meta-analyses conducted on cross-sectional and prospective studies suggest and IQ decline of 1 – 5 points is associated with an increase in lead blood level of 10 μg/dL. No threshold for the effects of lead on IQ has been identified.

Other effects from chronic lead exposure in humans include effects on blood pressure and kidney function, and interference with vitamin D metabolism. Animal studies have reported effects similar to those found in humans, with effects on the blood, kidneys, and nervous, immune, and cardiovascular systems noted.

The U.S. Environmental Protection Agency (EPA) has not established a Reference Concentration (RfC) or a Reference Dose (RfD) for elemental lead or inorganic lead compounds. EPA has established a Reference Dose for tetraethyl lead (an organometallic form of lead) of 1 x 10-7
milligrams per kilogram body weight per day (mg/kg/d) based on effects in the liver and thymus of rats.

Cancer Risk

Human studies are inconclusive regarding lead exposure and an increased cancer risk. Four major human studies of workers exposed to lead have been carried out; two studies did not find an association between lead exposure and cancer, one study found an increased incidence of respiratory
tract and kidney cancers, and the fourth study found excesses for lung and stomach cancers. However, all of these studies are limited in usefulness because the route(s) of exposure and levels of lead to which the workers were exposed were not reported. In addition, exposure to other chemicals
probably occurred. Animal studies have reported kidney tumors in rats and mice exposed to lead via the oral route. EPA considers lead to be a Group B2, probable human carcinogen. International Agency for Research on Cancer (IARC) considers inorganic lead compounds to be probably
carcinogenic to humans (Group 2A), and organic lead compounds to be not classifiable as to their carcinogenicity to humans (Group 3).

Reproductive/Developmental Effects

Studies on male lead workers have reported severe depression of sperm count and decreased function of the prostate and/or seminal vesicles at blood lead levels of 40 to 50 μg/dL. These effects may be seen from acute as well as chronic exposures. Occupational exposure to high levels of
lead has been associated with a high likelihood of spontaneous abortion in pregnant women. However, the lowest blood lead levels at which this occurs has not been established. These effects may also be seen from acute as well as chronic exposures. Exposure to lead during pregnancy
produces toxic effects on the human fetus, including increased risk of preterm delivery, low birthweight, and impaired mental development. These effects have been noted at maternal blood lead levels of 10 to 15 μg/dL, and possibly lower. Decreased IQ scores have been noted in children
at blood lead levels of approximately 10 to 50 μg/dL (ATSDR 1999).

Human studies are inconclusive regarding the association between lead exposure and other birth defects, while animal studies have shown a relationship between high lead exposure and birth defects.

Environmental Hazards

Lead is a naturally occurring, bluish-gray metal that is found in small quantities in the earth's crust. Lead is present in a variety of compounds such as lead acetate, lead chloride, lead chromate, lead nitrate, and lead oxide. Lead readily tarnishes in the atmosphere but it is one of the most stable
fabricated metals because of its corrosive resistance to air, water, and soil. Pure lead is insoluble in water; however, the lead compounds vary in solubility from insoluble to water soluble. The vapor pressure for lead is 1.00 mm Hg at 980° C (National Institute for Occupational Safety and Health
2004).

Lead particles are removed from the atmosphere by wet and dry deposition. The average residence time in the atmosphere is ten days, during which long distance transport up to thousands of kilometers may take place. Lead is extremely persistent in both water and soil. The presence of lead
in these media varies widely depending on such factors as temperature, pH, and the presence of humic materials. Biologists have studied the effects of lead sinkers and jigs on waterbirds, such as loons and swans, since the 1970s. A single fishing sinker swallowed with food or taken up as grit could be fatal to waterbirds. Lead adversely affects the function and structure of the kidney, central nervous system, bones, and production and development of blood cells in waterbirds. Exposure to lead, such as through ingestion of fishing sinkers, can cause lead poisoning in waterbirds, producing convulsions,coma, and death (USEPA 1994).

Exposure Routes

Worker Health

The primary use of lead in the U.S. is in the manufacture of batteries. Lead is also used in the production of metal products, such as sheet lead, solder (but no longer in food cans), and pipes, and in ceramic glazes, paint, ammunition, cable covering, and other products.

• The NIOSH REL for an 8 – 10 hour time-weighted-average exposure is 0.10 mg/m3 ( IARC 2004).
• The NIOSH IDLH is 100 mg/m3 ((IARC 2004).
• The OSHA PEL for an 8 hour work day is 0.5 mg/m3 (Smith 2003).
• The ACGIH TLV is 0.5 mg/m3 over an 8 hour workshift (Smith 2003).

Potentially high levels of lead occur in the following industries: primary and secondary lead smelting and refining industries, steel welding or cutting operations, battery manufacturing plants, construction, rubber products and plastics industries, printing industries, firing ranges, radiator repair shops, and other industries requiring flame soldering of lead solder. In these work areas, the major routes of lead exposure are inhalation and ingestion of lead-bearing dusts. In the smelting and refining of lead, mean concentrations of lead in air can reach 4,470 μg/m3; in the manufacture of
storage batteries mean airborne concentrations of lead from 50 to 5,400 μg/m3 have been recorded. (ATSDR 1999) The following bullets include various occupational threshold limits: Although combustion of leaded gasoline was one the primary source of anthropogenic atmospheric releases of lead, industrial releases from smelters, battery plants, chemical plants, and disturbance of older structures containing lead based paints are now major contributors to total lead releases.

Public Health

This section lists the major exposures of lead to the public, but is not intended to be an exhaustive listing of all potential exposures. The largest source of lead in the atmosphere has been from leaded gasoline combustion, but with the phase out of lead in automotive gasoline, air lead levels have decreased considerably. Other airborne sources include combustion of solid waste, coal, and oils, emissions from iron and steel production and lead smelters, general aviation aircraft, racing vehicle, marine fuels, and tobacco smoke.

Exposure of the general population to lead is most likely to occur through the ingestion of contaminated food and drinking water, and by the inhalation of lead particulates in ambient air. Fruits, vegetables, and grains may contain levels of lead in excess of background levels as a result of plant uptake of lead from soils and direct deposition of lead onto plant surfaces. Common source of exposure for children is lead-based paint that has deteriorated into paint chips and lead dusts, and common sources of lead exposure for adults include occupational and non-occupational such as doit-yourself paint scraping, renovations, and castings. For example, using heat guns or dry scraping of old lead containing paint during home reconstruction and remodeling can result in lead exposure.

Exposure to lead can also occur from food and soil. Children are at particular risk to lead exposure since they commonly put hands, toys, and other items in their mouths, which may come in contact with lead-containing dust and dirt. Lead-based paints were commonly used until 1978 and flaking paint, paint chips, and weathered paint powder may be a major source of lead exposure, particularly for children. Children are also exposed by handling lead-stabilized PVC plastics and lead alloy jewelry and toys. Lead in drinking water is due primarily to the presence of lead in certain pipes,
solder, and fixtures (i.e. brass fixtures).

Lead exposure to the general public can also occur during the use of inadequately glazed or heavily worn earthenware vessels for food storage and cooking, as well as by engaging in certain hobbies such as using recreational shooting ranges, stained glass making, or using molten lead in casting ammunition, fishing weights, or toy figurines.

Lead has been listed as a pollutant of concern to EPA's Great Waters Program due to its persistence in the environment, potential to bioaccumulate, and toxicity to humans and the environment. The National Ambient Air Quality Standard (NAAQS) are set by the U.S. EPA for pollutants that are considered to be harmful to public health and the environment. The NAAQS for lead is 1.5 μg/m3, which is the maximum arithmetic mean averaged over a calendar quarter (New Jersey Department of Health and Senior Services 2001).

3.1.3 Use and Functionality

The various physical properties of lead were outlined in Section 5.1.1. Lead may be used in the form of metal, alloyed with other metals, or as chemical compounds. The commercial importance of lead is based on its ease of casting, high density, low melting point, low strength, ease of fabrication, acid resistance, electrochemical reaction with sulfuric acid, and chemical stability in air, water, and soil. Many of the physical properties of lead are desirable for various product categories such as storage batteries, ammunition, casting materials, and sheet lead. The total global consumption of lead in 2003 was estimated to be 15.1 billion pounds, and the U.S. consumption of lead in 2003 was estimated to be 3.06 billion pounds. The greatest use of lead is in lead-acid batteries, however leadacid batteries are not manufactured in Massachusetts (USEPA 1999).

3.2 Lead Use Identification and Prioritization

3.2.1 Use Identification

Lead has many desirable material properties and has a variety of uses. A summary of the major uses is provided below. (Please see Appendix B for a more detailed description of the various uses of lead).

• Batteries
• Ammunition
• Glass
• Heat Stabilizer in Plastics & Resins
• Metal Finishing
• Electronics (solder, board surface finish, components)
• Sheet Lead (sound barriers, roof flashing, radiation shielding)
• Bulk Metal (castings, weighting applications, ammunition)
• Pigments

In order to determine which uses were a priority for assessment in Massachusetts, the following criteria were evaluated:

1. Importance to the Commonwealth of Massachusetts:

• Use in manufacturing: Total quantity of chemical used in manufacturing operations in Massachusetts
• Use in consumer products: Total quantity of chemical used in products sold in Massachusetts.

2. Potential availability of alternatives.

3. Exposure potential (environmental, occupational, and public health).

4. Potential value to Massachusetts businesses and citizens of the alternatives assessment results.

Specifically, the preferences of the pertinent stakeholders for each chemical were given priority. This stakeholder input was provided during a stakeholder meeting held during October 2006, and from a stakeholder input survey.

Uses in products

The following table illustrates the uses of lead in various products:

See Table 3.2 A: Uses of Lead

Use in Massachusetts Manufacturing/Operations

The following table illustrates the uses of lead in various manufacturing and operations in Massachusetts. This table includes lead use as reported by Massachusetts facilities covered by the Toxics Use Reduction Act (TURA). This is not an exhaustive list because it does not include facilities with less than ten employees, facilities with SIC codes not covered by TURA, and facilities using less than TURA defined threshold amounts.

See Table 3.2 B: Use of Lead in Massachusetts

Lead Releases in Massachusetts

The following table illustrates the releases of lead in Massachusetts. This table is not an exhaustive listing of releases because it is limited to the generators covered under the U.S. EPA Toxics Release Inventory program.

See Table 3.2 C: Lead Released in Massachusetts

Summary of Stakeholder Input

Stakeholder participation at the October 2005 and November 2005 stakeholder meetings included Massachusetts representatives from industry, government, and environmental organizations. The following considerations were evaluated during the prioritization process for the major uses of lead.

Batteries

• Highest level of lead use accounting for approximately 84% of all lead use in the United States.
• In general, there is a good infrastructure in place for recycling lead in batteries at product end of life.
• Many available battery alternatives contain nickel, cadmium, or other toxic materials.
• Most safer battery alternative technologies are still emerging.

Electronics

• Broad use in Massachusetts by approximately 59 facilities in the electronics industry. However, only a small quantity of lead is incorporated into the product.
• The European Union’s directive called Restriction of the use of certain Hazardous Substances (RoHS) restricts the use of lead in many electronics applications. This directive has initiated a movement toward lead-free electronics for affected electronics companies in Massachusetts.
• The electronics industry has already moved toward a standard alternative for lead solder. This alternative is an alloy consisting of tin, copper, and silver (SAC alloy). The Institute has been involved with the electronics industry researching, testing, and evaluating this lead-free alloy for electronics assembly for the past five years.
• The U.S. EPA Design for Environment project has recently completed a comprehensive life cycle analysis for lead and lead-free solders. Therefore, by undertaking an alternatives assessment for lead solder we wouldn’t be adding much value to decision making by companies.

Sheet Lead

• Sheet lead is used mostly for roof flashing and radiation shielding applications.
• Lead works well for radiation shielding. For this use, the lead is often isolated from exposure during use and the lead is also easily recyclable.
• There are many commercially available alternatives for lead roof flashing.
• There were health concerns for construction workers and home owners using lead roof flashing.
• Lead use in roof flashing was considered to be added to the priority list if additional time and resources were made available in 2006.

Heat Stabilizers in PVC and Elastomers

• The largest use in Massachusetts manufacturing, accounting for 42% of lead use. Thirty-nine manufacturing facilities in Massachusetts reported a total of approximately 4 million pounds in 2003.
• Many lead-free heat stabilizers are commercially available, and companies are adopting alternative heat stabilizers.
• The U.S. EPA Design for Environment project is underway to evaluate three specific wire/cable applications. In the longer term, this effort will provide life cycle assessment information for several heat stabilizer alternatives.
• There is little or no recycling at end of life for PVC products containing lead.
• An overview of the current market situation for lead-free heat stabilizers would provide high value to Massachusetts manufacturers. There is value to understanding in the short term the various alternatives available before substitutions are made. Wire and cable is an excellent example of lead heat stabilizers used in PVC products.

Weight Applications: Wheel Weights

• Wheel weights commonly become detached from automobile wheels and end up in the environment.
• Several alternatives are in use and are commercially available.
• The Ecology Center of Ann Arbor, Michigan has already gathered some wheel weight information that will be valuable for conducting an alternatives assessment.
• Worker exposure is a concern during installation of wheel weights for new automobiles as well as during after market installation.
• Wheel weights are a good example of lead used in weighting applications. Conducting an alternatives assessment in this area will provide high value to address worker exposure and environmental concerns.

Weight Applications: Fishing Sinkers

• Several states in the Northeast have banned the use of certain lead sinkers. Massachusetts still allows the use of lead fishing sinkers except for use in the Quabbin and Wachusett Reservoirs.
• Several lead-free alternatives are in use and are commercially available.
• Fishing sinkers of all types are lost during use. These fishing sinkers end up in the environment and some of these lead sinkers are ingested by waterfowl.
• Thousands of anglers in the U.S. produce their own lead fishing sinkers.
• Fishing sinkers are a good example of lead used in weighting applications. Conducting an alternatives assessment in this area will provide high value to address wildlife and environmental concerns, as well as health concerns during production and use of lead sinkers by individual anglers.

Ammunition for Shooting Ranges

• Second highest use of lead, accounting for approximately 4% of lead use in the United States.
• For outdoor shooting ranges in Massachusetts, the lead in ammunition usually ends up in the environment and often leads to soil and/or sediment contamination and potentially surface water and groundwater contamination. .
• For indoor shooting ranges, there is high worker and shooter exposure to lead.
• Several alternatives are in use and are commercially available.
• There is a Massachusetts manufacturer of firearms that uses lead ammunition for testing purposes.
• Conducting an alternatives assessment in this area will provide high value to shooting range workers, shooting enthusiasts and public safety personnel.

Pigments

• Most uses of lead pigments have been phased out.
• Lead pigments are primarily used for traffic paint in Massachusetts.
• The single Massachusetts manufacturer of traffic paint is transitioning to a lead-free alternative.
• Lead use in pigments was considered to be added to the priority list if additional time and resources were available.

Castings/Extrusion (jewelry, ornamental, etc.)

• There are 17 TURA filers in Massachusetts that used approximately 190,000 pounds of lead in 2003.
• There is a potentially high consumer exposure during use, especially in children’s jewelry.
• Most children’s jewelry is now imported, so there is limited control on material selection for foreign manufacturers.
• There are some alternatives commercially available.

In addition to the stakeholder meeting, a survey was provided to stakeholders to solicit their input to prioritize the various uses of lead. Four stakeholders completed and returned this survey. In general, the stakeholder input for the various uses of lead fell into one of the following three categories outlined in the following table:

See Table 3.2 D: Stakeholder Input

3.2.2 Use Prioritization

Based upon applying the criteria discussed above, the following three applications were selected as priority lead uses for this alternatives assessment project: In summary, these applications were chosen based on stakeholder input, importance to Massachusetts industry and consumers, and likely availability of alternatives. Ammunition when used at indoor and outdoor firing ranges was thought to be a significant source of lead contamination in the Commonwealth. Wheel weights and fishing to be a significant source of lead contamination in the Commonwealth. Wheel weights and fishing sinkers were chosen to be representative of a large number of lead uses that rely on its high density. Wire and cable heat stabilization is the category with the largest use of lead among Massachusetts manufacturers. The priority uses of lead that will be studied are:

• Ammunition for shooting ranges;
• Weighting applications (wheel weights and fishing sinkers);
• Heat stabilizers used in PVC wire and cable coatings.

3.3 Lead Alternatives Identification and Prioritization

Since there are so many alternatives for the various uses of lead, the Institute was not able to fully evaluate them all in the short time span allowed for this project. Therefore, the Institute conducted an evaluation to determine those alternatives that are most feasible based upon the following criteria:

• Performance: Known performance of alternative compared to that of the hazardous chemical. Consider the potential for future performance enhancements (e.g. research funds available for further product development).
• Availability: Number of suppliers/manufacturers that commercially provide the alternative.
• Manufacturing Location: Is the product manufactured in Massachusetts or outside of Massachusetts.
• Cost: Current costs associated with the alternative compared to that of the hazardous chemical. Consider the potential for future cost reductions (e.g., economies of scale due to higher volume production).
• Environmental, Health, and Safety: Known environmental, health and safety risks compared to that of the hazardous chemical.
• Global Market Effect: Information about pending or existing global restrictions that might materially affect the ability of an industry to market its products internationally.
• Stakeholder Value: Stakeholders placing a high priority on a particular alternative so as to inform their decisions.

3.3.1 Alternatives Associated with Ammunition for Shooting Ranges

Available Alternatives

Alternatives based on the following substances were identified:

• Bismuth
• Copper
• Iron
• Tungsten
• Zinc
• Brass
• Bronze
• Ceramic
• Plastic/polymeric
• Steel
• Tin
• Beryllium

Alternative Screening

Beryllium and beryllium compounds: The U.S. Department of Health and Human Services and the International Agency for Research on Cancer have determined that beryllium and beryllium compounds are human carcinogens. EPA has determined that beryllium is a probable human carcinogen.

Alternatives Prioritization

A law passed in 1986 makes it unlawful to manufacture or import armor-piercing ammunition, which eliminates the possibility of producing handgun ammunition using tungsten alloys, steel, iron, brass, bronze, beryllium copper, or depleted uranium, unless the projectiles are frangible (break apart into small pieces on contact with any hard surface) and are intended for target shooting applications.

Bismuth

Bismuth is similar to lead in density and softness and therefore has the advantage of having ballistic performance which is similar to lead. At least one major ammunition manufacturer produces bismuth handgun bullets. Bismuth is used to produce frangible bullets by plating a cast bismuth core with a copper jacket, or by mixing bismuth with other materials including polyethylene or zinc. Preliminary research indicates that bismuth is a less toxic alternative to lead for use in handgun ammunition used at indoor firing ranges. In January of 1997, bismuth-tin shotgun shot was granted full approval by the U.S. Fish and Wildlife Service as an alternative to lead shotgun shot for hunting migratory waterfowl.

Copper

Copper is widely used as a jacket material for both lead and lead-free bullets. Copper powder is also used to produce frangible bullets, typically in a mixture with other powdered metals including tin, iron, or tungsten. Copper has a density of 8.9 g/cm3 which is 22% less than lead and will result in either lighter bullets or increased bullet size. Several major ammunition manufacturers use copper and/or copper powder to produce lead-free handgun ammunition. The cost of copper is roughly 3.5 times the cost of lead. Frangible handgun ammunition made with sintered (heated without melting to form a coherent mass) copper powder is significantly more expensive than lead ammunition but it is competitive with other types of frangible ammunition or reduced hazard ammunition.

Iron

Iron powder has successfully been used to produce frangible handgun bullets. Iron has a density of approximately 7.6 g/cm3 which is 32% less than lead and will result in either lighter bullets or increased bullet size. Iron handgun bullets, excluding frangible bullets, are banned because they are considered to be armor piercing ammunition. Frangible handgun ammunition made with iron powder is significantly more expensive than lead ammunition but it is competitive with other types of frangible ammunition or reduced hazard ammunition. Iron has the advantage of being magnetic which could facilitate recovery for recycling.

Tungsten

Tungsten has a density of 19.25 g/cm3 which is 1.7 times the density of lead. Tungsten ammunition can be produced to provide similar ballistic performance to lead ammunition. Several major ammunition manufacturers produce lead-free frangible ammunition using tungsten. Tungsten alloy handgun bullets, excluding frangible bullets, are banned because they are considered to be armor piercing ammunition.

Frangible handgun ammunition made with tungsten is significantly more expensive than lead ammunition but it is competitive with other types of frangible ammunition or reduced hazard ammunition. In January of 1997, several types of tungsten shotgun shot were granted full approval by the U.S. Fish and Wildlife Service as alternatives to lead shotgun shot for hunting migratory waterfowl.

Zinc

Zinc has a density of 7.05 g/cm3 which is 62% of the density of lead will result in either lighter bullets or increased bullet size. Zinc can be used to produce frangible bullets either by forming the bullets out of zinc powder or zinc wire. Considering commodity prices of metals, zinc is one of the least expensive alternatives to lead. It is approximately twice the cost of lead.

Based on the previously listed criteria, alternatives based on the following materials were given a lower priority for assessment.

Brass: Brass handgun bullets, excluding frangible bullets, are banned because they are considered to be armor piercing ammunition. Based on internet searches of ammunition manufacturers’ and dealers’ websites, brass frangible handgun bullets do not appear to be available in the commercial marketplace.

1. Bronze: Bronze handgun bullets, excluding frangible bullets, are banned because they are considered to be armor piercing ammunition. Based on internet searches of ammunition manufacturers’ and dealers’ websites, bronze frangible handgun bullets do not appear to be available in the commercial marketplace.
2. Ceramic: Ceramic bullets are significantly lighter than lead bullets which results in differences in ballistic performance. Ceramic bullets are used in some training applications where frangible bullets are required but, according to Richard Patterson (SAAMI), ceramic bullets are not widely accepted as a substitute for lead handgun bullets because the low density of ceramic negatively impacts performance.
3. Plastic: Molded plastic bullets are available for limited target practice. These reusable lightweight handgun bullets use primer power alone (no powder load) and therefore have velocities of only 300-400 feet per second and a range of only 25 feet. Since they do not utilize a powder load there is no recoil and the ballistic performance is significantly different from lead bullets.
4. Steel: Steel handgun bullets are banned because they are considered to be armor piercing ammunition. Based on internet searches of ammunition manufacturers’ and dealers’ websites, steel frangible handgun bullets do not appear to be available in the commercial marketplace.
5. Tin: Tin is used as a minor component in several types of bullets including lead, tungsten, and copper bullets. One major manufacturer produces ammunition with a tin core and copper jacket.Several of the alternatives that contain tin are included in the assessment but are included under the primary materials such as copper and tungsten.

High Priority Ammunition for Shooting Ranges Alternatives

The following alternative ammunitions were selected for assessment:

• Bismuth
• Copper
• Iron
• Tungsten
• Zinc

3.3.2 Alternatives Associated with Wheel Weights

Available Alternatives

The following were identified as potential alternatives to lead wheel weights:

• Zinc and ZAMAC (an alloy of zinc, aluminum and copper)
• Steel
• Plastic
• Copper
• Steel
• Tin
• Tungsten
• Iron
• Internal balancing systems, including plastic beads or other material inserted into the tire

Several European and Japanese automobile manufacturers have already switched to zinc or steel wheel weights. While auto manufacturers are making some progress to switch to lead-free wheel weights, the Institute noted that 80% of wheel weights are used by aftermarket businesses such as tire retailers and service stations and very few of these businesses use lead-free wheel weights.

Alternatives Prioritization

Alternatives that appeared likely to meet the following performance criteria were given a higher priority for assessment:

• Should meet automotive industry standards and specifications established for lead wheel weights
• Should be made of a dense material to minimize size
• Should be corrosion resistant
• Should be resistant to high temperatures
• Should be recyclable

Copper

Copper has several properties that match the requirements of wheel weight applications. It is relatively dense (8.9 g/cm3), it is ductile and it is corrosion resistant. One manufacturer states that copper is ideal for high quality adhesive weights where small size, appearance and balance accuracy are important. One major UK manufacturer produces copper adhesive weights; copper wheel weights are not manufactured in Massachusetts.

Steel

Steel weights are susceptible to corrosion and therefore must be coated. One manufacturer uses a sacrificial zinc corrosion protection plus a plastic coating. Steel is not ductile and therefore it is more suited for adhesive weights than clip-on weights. Steel wheel weights are currently manufactured in Tennessee, Japan, UK, and Austria. Steel is a relatively inexpensive metal and it is possible that steel weights would cost less than lead weights. Steel is currently used for a wide range of products including automobile wheels and other automotive components.

Tin

One wheel weight manufacturer states that tin offers a high quality appearance with a good color match to alloy wheels and does not require corrosion protection. Tin wheel weights are currently manufactured by companies in India and the UK. No tin wheel weight manufacturers are located in Massachusetts. Based on the higher cost of tin, it is expected that tin wheel weights would cost more than lead weights.

Zinc and zinc alloy (ZAMAC – ZnAl4Cu1)

Zinc has a density of 7.05 g/cm3 which is 62% of the density of lead and therefore zinc wheel weights will have the disadvantage of being larger than lead weights. Zinc is successfully being used for both clip-on and adhesive type wheel weights.

Zinc and/or zinc alloy wheel weights are manufactured by companies in Tennessee, Austria, Germany, Thailand, and the UK. No zinc wheel weight manufacturers are located in Massachusetts. Zinc clip-on weights are typically more expensive than uncoated lead clip-on weights but zinc weights are likely to be comparable in price to higher quality coated lead weights. Unless zinc weights are clearly marked or labeled, they are not easily distinguishable from lead weights and therefore will likely cause contamination problems for lead smelters during the recycling of lead
wheel weights.

Based on the previously listed criteria, alternatives based on the following materials were given a lower priority for assessment

1. Tungsten: Tungsten has the advantage of being more dense than lead and could be used as a pure metal, as an alloy with other metals, or as a filler for plastic weights. A study by Okopol Institute for Ecology and Political Affairs concluded that tungsten was not a realistic alternative for lead wheel weights due to the high price of tungsten, which could be 100 times the price of lead. The study also stated that world-wide production of tungsten is only 31,500 tons per year while demand for wheel weights is 12,000 tons per year.
2. Iron: Iron was not found to be used for wheel weights, most likely because iron is not corrosion resistant.
3. Plastic (Polypropylene): A European study on the use of heavy metals in vehicles (Lohse, 2001) identified talc filled polypropylene as an alternative material for wheel weights but additional information on the use of polypropylene was not located. Polypropylene has the disadvantages of being a low density materiel and having a low melting point. The European study indicated that talc filled wheel weights have a density of less than 5.2 g/cm3, which is less than half the density of lead, and that they would fail at temperatures above 120° C.
4. Internal Balancing Systems: Internal balancing systems incorporate the weights, such as plastic beads, inside the tire. One advantage of internal balancing systems is that the weights will not fall off of the wheel since they are contained within the tire. These systems are also likely to be dynamic balancing systems, providing balancing even as the tire wears. A major barrier to adopting internal balancing systems is that they are not drop-in replacements to lead wheel weights. They are likely to require changes to tire balancing equipment and/or tire designs.

High Priority Alternatives for Lead Wheel Weights

The following alternative materials were selected for assessment:

• Copper
• Steel
• Tin
• Zinc and Zinc Alloy (ZAMAC)

3.3.3 Alternatives Associated with Fishing Sinkers

Available Alternatives

The following were identified as potential alternatives to lead fishing sinkers:

• Bismuth and bismuth/tin
• Brass
• Tin
• Copper
• Iron
• Ceramic
• Zinc
• Steel
• Tungsten, tungsten/nickel alloy and tungsten/polymer composite

Alternatives Prioritization

Alternatives that appeared likely to meet the following performance criteria were given a higher priority for assessment

• Adequate density to minimize size
• Smooth finish to reduce line wear
• Corrosion resistance
• Durability
• Scent absorption (some applications)
• Coloring (some applications)

Bismuth

Bismuth has successfully been used as a replacement for lead for some fishing sinker applications. One manufacturer of bismuth fishing sinkers is located in Minnesota.

Bismuth worm weights were found to be 3 to 6 times the cost of the equivalent lead weights. Preliminary research indicates that bismuth is a less toxic alternative to lead for use in fishing sinkers. The EPA stated that it did not discover any information on the toxicity of bismuth to avian or aquatic species (USEPA 1994).

Ceramic

Ceramic has successfully been used as a replacement for lead for some fishing sinker applications. Ceramic is less dense than lead and therefore ceramic weights are larger than lead weights. The larger size of ceramic weights could be a disadvantage in some applications but one manufacturer states that the larger size and lower density of ceramic weights decreases snags and the likelihood of getting caught on rocks. The color and noise created when using ceramic sinkers is also said to attract fish. Ceramic weights are currently produced by at least one manufacturer in Pennsylvania, but ceramic sinkers are not available at some of the major online fishing equipment retailers. Ceramic sinkers are likely to cost more than equivalent lead sinkers.

Steel

Steel has successfully been used as a replacement for lead for some fishing sinker applications. Steel is less dense than lead and therefore steel weights are larger than lead weights. In order to prevent corrosion, the steel weights must be coated or be made from a stainless steel. Steel fishing sinkers are produced by several companies in the U.S. and Canada. Steel sinkers can be cost competitive with lead sinkers. For some sizes, the price of steel egg sinkers was only 75% of the price of equivalent lead sinkers. The EPA stated that it did not discover any information on the toxicity of steel to mammalian or aquatic species. EPA believes that steel would have low potential toxicity to those species. No adverse toxicological effects from steel have been indicated as a result of a research program conducted by the Fish and Wildlife Service to replace lead shot with steel shot, which examined toxicity to ducks of five proposed substitute shot metals (USEPA 1994).

Tin

Tin is widely used as a substitute for lead split-shot fishing weights because its ductility meets the requirements of this application. At 7.35 g/cm3, tin is not as dense as lead and therefore the tin weights would be larger but it is not clear that this is either an advantage or disadvantage. Tin fishing
sinkers are produced by several companies in the U.S. and Canada. At one major fishing equipment retailer, tin reusable split-shot sinkers are 1.5 to 2.5 times the price of the equivalent lead sinkers, depending on size and quantity. EPA states that tin, in the inorganic form, is generally much less toxic to aquatic organisms than lead because of its low solubility, poor absorption, low uptake rate, and rapid excretion. It appears that tin is much less toxic to waterbirds and mammals than lead. (United States Environmental Protection Agency (USEPA 1994).

Tungsten

Tungsten has successfully been used as a replacement for lead for some fishing sinker applications. Manufacturers state that tungsten fishing sinkers have the advantage of being smaller and harder than lead sinkers and therefore are less likely to get hung-up on rocks. They also claim that fish are attracted to the noise created by tungsten sinkers. Tungsten fishing sinkers are manufactured by several companies in the U.S. and Canada, including at least one company in Massachusetts. Tungsten worm weights were found to be 7 to 11 times the cost of the equivalent lead weights.
The EPA stated that it did not discover any information on the toxicity of tungsten to avian species. Tungsten was found to have low toxicity to aquatic organisms (crustaceans and algae). The toxicity of tungsten to aquatic organisms (daphnids and algae), and mammals (rats) is less than lead based on laboratory studies (USEPA 1994).

Based on the previously listed criteria, alternatives based on the following materials were given a lower priority for assessment

1. Brass: Brass is an alloy of zinc, copper, and lead. The lead in brass may be either intentionally added or exist as an impurity. EPA stated that even though the toxicity of brass to waterbirds has not been tested, based on the toxicity of lead and zinc, brass with and without lead would also be very toxic to waterbirds.
2. Copper: EPA states that laboratory studies indicate that copper is more toxic to aquatic organisms and algae than lead. However, EPA believes that environmental conditions in freshwaters would mitigate the toxicity of copper metal to aquatic organisms. The toxicity of copper to avian species is less than that of lead.
3. Iron: Iron was not found to be used for fishing sinkers, most likely because iron is not corrosion resistant.
4. Zinc: EPA found that zinc is more toxic to aquatic organisms than lead, that it may be bioconcentrated by invertebrates and algae, and it may be more bioavailable to aquatic organisms. EPA believes that environmental conditions could mitigate the toxicity of zinc to a certain extent in freshwaters to aquatic organisms because it is more soluble than lead. Zinc is toxic to mammals and avian species (USEPA 1994).

High Priority Alternatives

The following alternative materials were selected for assessment for fishing sinkers:

• Bismuth
• Ceramic
• Steel
• Tin
• Tungsten

3.3.4 Alternatives Associated with Heat Stabilizers for PVC Wire & Cable Coatings

Available Alternatives

The following were identified as potential alternatives to lead-based heat stabilizers for PVC in wire and cable:

• Mixed metal stabilizers based on:
  
  • Calcium-zinc
  • Barium-zinc
  • Magnesium-zinc
  • Magnesium aluminum hydroxide carbonate hydrate
  • Magnesium zinc aluminum hydroxide carbonate
  • Barium-calcium-zinc
  • Barium-cadmium-zinc
  • Ester thiol
  • Organotins

Alternatives Screening

The only alternative that was screened out was the barium-cadmium-zinc alternative based on the carcinogenicity criterion. The U.S. EPA has classified cadmium as a Group B1 carcinogen, a probable human carcinogen. IARC has classified cadmium as a Group 2A, probable human carcinogen.

Alternatives Prioritization

Stakeholders provided input on performance criteria, including:

• Heat stabilizer requirements for PVC processing at temperatures between 160 to 210 degrees Celsius. Also, the stabilizers elevate the resistance of PVC products during use against moisture, visible light, ultraviolet rays, and heat.
• Basic properties of lead that make it desirable for use as a heat stabilizer in PVC wire and cable applications
• Alternatives identified to date, including various mixed metal and organotin technologies.

There were many alternatives to lead available for use as a heat stabilizer for PVC wire and cable applications. Since there are so many alternatives for this use of lead, the Institute was not able to fully evaluate them all in the short time span allowed for this project. Therefore, we conducted an evaluation to determine those alternatives that are most feasible, and/or those alternatives that were representative of a class of alternatives, based upon the criteria listed earlier in this section.

Based upon applying the criteria, the following five alternatives for using lead as a heat stabilizer were selected as high priorities for assessment:

1. Calcium-zinc
2. Barium-zinc
3. Magnesium-zinc
4. Magnesium aluminum hydroxide carbonate hydrate
5. Magnesium zinc aluminum hydroxide carbonate

All of the five alternatives can be categorized as mixed metal stabilizers. This family of stabilizers has achieved growing market acceptance as a non-lead heat stabilizer for PVC wire and cable applications. Each of the five alternatives is manufactured by at least one major heat stabilizer manufacturer.

Based on the previously listed criteria, alternatives based on the following materials were given a lower priority for assessment.

The ester thiols and organotin alternatives were available for use as a heat stabilizer for flexible PVC applications. However, commercially available products were not found for specific use in PVC wire and cable applications.

High Priority Alternatives

The following alternative materials were selected for assessment for PVC heat stabilizers in wire and cable:

• Calcium-zinc
• Barium-zinc
• Magnesium-zinc
• Magnesium aluminum hydroxide carbonate hydrate
• Magnesium zinc aluminum hydroxide carbonate

3.4 Lead Alternatives Assessment

3.4.1 Alternatives Assessment for Ammunition for Shooting Ranges

Technical Assessment

The focus of this assessment is on alternatives to lead bullets used in handgun training ammunition for use at indoor firing ranges. Ammunition marketed for training applications is designed to be inexpensive and is not designed to meet the performance criteria required for service or duty ammunition. Ammunition designed for competitions, hunting or for use by law enforcement is typically more costly than training ammunition because it is designed for increased accuracy or has features, such as a hollow point, which improve performance for the intended application.

It should be noted that conventional handgun ammunition contains lead in both the projectile (bullet) and the primer. However, the scope of this assessment is limited to alternatives to the lead used for the projectile.

Lead-free or reduced lead ammunition is available in the following configurations:
Totally Lead-Free: Lead-free bullets and lead-free primer.
Lead-Free Primer: Lead bullets with lead-free primer. Ammunition with lead-free primer and a lead bullet with a copper jacket that has a totally enclosed base is referred to as firing line safe ammunition because these features reduce the lead vapor generated during firing.
Lead-free Bullets: Lead-free bullets with conventional primer, which contains lead and other heavy metals.
Frangible Lead-Free Bullets: Lead-free bullets that break up into small fragments upon impact with a hard target. Frangible ammunition may utilize either conventional or lead-free primer.

Longevity/Life in Service

The shelf-life of conventional handgun ammunition can be virtually indefinite if it is stored in a cool, dry environment, free of contaminants (Patterson 2006b). It is the primer that typically limits the shelf-life because it is most susceptible to degradation from elements such as excess heat, moisture, and contaminants. The bullet material does not affect the shelf-life of ammunition and several ammunition manufacturers state that their ammunition with lead-free bullets and conventional lead primer has the same shelf-life as conventional lead ammunition.

Key Standards for Component/End-product

U.S. standards for firearms and ammunition are developed and promulgated by the Sporting Arms and Ammunitions Manufacturers’ Institute, Inc. (SAAMI), an accredited standards developer for ANSI. SAAMI was established to standardize case and chamber specifications so any ammunition of a given caliber and type will fit and function safely in any firearm designed for that caliber and type of ammunition. SAAMI standards define the safe range of internal ballistic pressures for a given firearm/ammunition combination and provide specifications required to achieve the safe pressures.
(Sporting Arms and Ammunitions Manufacturers Institute, Inc. (SAAMI) 2006) Gun manufacturers recommend the use of ammunition with internal ballistic pressures that meet SAAMI specifications.

The Bureau of Alcohol, Tobacco and Firearms (BATF) has banned handgun ammunition made from the following materials because it may be considered armor piercing: tungsten alloys, steel, iron, brass, bronze, beryllium copper and depleted uranium. These materials can be used if the
projectiles are frangible and are intended for target shooting applications. The ammunition considered in this study used frangible projectiles (bullets) with the exception of the solid copper bullets and the jacketed stranded zinc bullets and this ammunition was intended for target shooting.
Therefore, none of the alternatives were classified by BATF as armor piercing (Bureau of Alcohol, Tobacco, Firearms and Explosives (BATF)).

Key Physical Characteristics and Key Performance Requirements

Density:

The relatively high density of lead (11.34 g/cm3) is one of the properties that make it the primary material used for bullets. With a density of 19.3 g/cm3, tungsten has the highest density of the alternatives in this assessment, followed by bismuth (9.8 g/cm3), copper (8.9 g/cm3), iron (7.8 g/cm3), and zinc (7.10 g/cm3) (Automation Creations).

Hardness and Malleability:

Lead is a soft malleable metal. These characteristics help to limit internal pressures generated when a firearm is fired. It is critical that internal pressures are limited to avoid damage to the firearm and potentially dangerous conditions. The malleability of the bullet is one of several factors that affect internal pressures. When the propellant is ignited and first starts to push the bullet into the rifling, internal pressures rise dramatically. The softness and malleability of lead and the traditional construction of jacketed lead bullets provide cushioning and serve to reduce the initial peak
pressure.

The base metals used for the lead-free alternatives are harder than lead as can be seen in Table 3.4.1A. However, information on the actual hardness and malleability of the alternatives was not available because the alternatives are composed of alloys or mixtures of metal powder and other materials such as plastic. If the softness and malleability of the alternatives is not sufficient to limit internal pressures, the manufacturer can limit peak pressures by making other design changes such as reduced power loading, changing the propellant formulation, using softer jacket material or
making dimensional changes.

Table 3.4.1A: Hardness of Ammonium Base Metals

Bullet weight:

The mass of a bullet affects the ballistic performance of ammunition and, for many applications, a higher bullet mass is desirable. The mass of a bullet is a function of the size of the bullet and the density of the bullet material. However, the size of the bullet is dictated by gun dimensions and therefore the bullet weight is driven primarily by the density of the bullet material.

Lead bullets are often available in two or three weights for a given caliber while lead-free bullets are generally available in only one weight for a given caliber. A lead-free bullet typically has a mass that is equal to, or less than, the smallest lead bullet available in that caliber. For example, lead 9 mm ammunition is available in 115, 124 and 147 grain (15.43 grains = 1 gram) bullet weights while 9 mm ammunition with lead-free bullets typically has a bullet weight of 115 grains or less.

According to a manufacturer of bismuth ammunition, Bismuth Cartridge Co., since bismuth is nearly as dense as lead it is possible to manufacture bismuth frangible bullets that match the weight of many lead bullets. For example, the company produces 9 mm frangible bismuth ammunition in 115 grain and 124 grain bullet weights.

The lower density of copper results in bullets that have less mass than equivalent lead bullets. For example, frangible 9 mm ammunition composed of 90% powdered copper and 10% powdered tin is available from several manufacturers (Federal, International and Winchester) with bullet weights ranging from 90 to 100 grains. Ammunition composed of copper powder and a polymer was produced by PMC in the 9 mm caliber with a bullet weight of 77 grains. Solid copper 9 mm bullets are available from one manufacturer in a 115 grain bullet weight (Barnes Bullets).

Frangible 9 mm ammunition composed of powdered iron is available from at least one manufacturer with a 105 grain bullet weight (Remington Arms Company, Inc.). One ammunition manufacturer produced tungsten/nylon frangible 9 mm ammunition with a 115 grain bullet weight, but this product was discontinued (Nowak 2006). Stranded zinc 9 mm ammunition is available from at least one manufacturer with a 100 grain bullet weight (Federal Cartridge Company).

Recoil:

When training with a handgun, it is desirable to use training ammunition that provides the same “feel” as duty ammunition. One factor that affects the “feel” of firing a handgun is the amount of recoil and one of the factors that affect recoil is the weight of the bullet. Recoil is of particular concern for lead-free training ammunition, since lead-free bullets often have a lower bullet weight than lead duty ammunition.

Bismuth Cartridge Co. states that it can produce frangible bismuth ammunition for training that matches the recoil of duty load (lead ammunition) used by law enforcement agencies. (Bismuth Cartridge Company)In its law enforcement ammunition catalog, Federal Cartridge Co. states that the felt recoil of its BallistiClean stranded zinc core ammunition is comparable to service ammunition (Federal Cartridge Company).

A study conducted by the New Jersey Division of Criminal Justice found that several types of leadfree ammunition provided sufficient recoil to meet the “equivalent load” standard. In the 9 mm caliber, the following ammunition received a passing grade for felt recoil (Zamrok 2004):

• Bismuth Cartridge Co. No-Tox, 115 grain (bismuth with copper jacket)
• Federal CQT, 100 grain (stranded zinc with copper jacket)
• International Greenline, 75+P and 100 grain (powdered copper/tin)
• Speer Lawman RHT, 100 grain (copper)
• Winchester SF LE, 100+P grain (powdered copper/tin)
• Winchester SuperClean NT, 105 grain (tin core with copper jacket)

The following ammunition received a failing grade for felt recoil:

• Remington Disintegrator, 105 grain (iron powder with copper jacket)
• Delta 115 grain (copper)
• Winchester Ranger, 85 grain (tungsten/nylon)

Ammunition manufacturers usually provide information about the ballistics of their ammunition products, including bullet velocity, energy and trajectory. Bullet velocity and energy are typically measured at the muzzle of the gun (muzzle velocity and muzzle energy) as well as at certain distances, such as 50 and 100 yards. The values for bullet velocity and energy used in this assessment were those measured at the muzzle of the gun because these values were the most readily available. Data were gathered on the muzzle velocity and muzzle energy of 9 mm lead and lead-free handgun bullets.

There are a number of factors that affect bullet velocity and energy, including bullet weight and the amount of gunpowder in the cartridge. With all other factors equal, a lead-free bullet must have the same weight as a lead bullet to achieve the same bullet velocity and energy. Bullet velocity affects bullet energy and some manufacturers increase velocity for the lighter lead-free bullets to reach the target bullet energy. Due to the number of factors that affect bullet velocity and energy, this assessment did not attempt to compare the performance of lead-free bullets with lead bullets in this
area.

Table 3.1.4 B lists examples of the bullet muzzle velocity and muzzle energy for both lead and leadfree ammunition.

Table 3.4.1 B: Muzzle Velocity and Muzzle Energy Comparison

Terminal Ballistics

Many of the lead-free bullets reviewed in this assessment are frangible, which means they fragment into small particles upon impact with a target. Frangible lead-free bullets are typically viewed as being safer than lead bullets for use at indoor firing ranges because they reduce or eliminate the dangers associated with ricocheting bullet fragments. This is of particular concern when firing at steel targets at close range. Frangible bullets can also limit damage to steel targets. Frangible lead bullets are not currently available.

Frangible bullets made of bismuth, iron, tungsten/nylon or powdered copper fragment into dust when shot into steel targets, reducing the potential for ricochet. The Remington frangible iron ammunition is reduced to dust with fragments of copper from the plated jacket. Remington test data
show that 64.5% of the particles hit the floor within 5 ft and 97.2% within 10 ft.

The core of the stranded zinc ammunition consists of zinc cables arranged in a spiral fashion. The cables break apart upon entering a target (Federal Cartridge Company). It is not clear whether stranded zinc ammunition ricochets more or less than lead bullets.

Solid copper bullets are not frangible and may ricochet more than lead bullets because copper is stiffer than lead (Jones 2001).

Barrel Fouling and Barrel Wear

When a bullet is fired, the ignition of the gunpowder generates both heat and pressure. The pressure forces the bullet down the barrel of the gun, where the rifling is engraved into the bullet. This rifling in the barrel causes the bullet to spin. Depending on the bullet composition and design, the combination of pressure, friction and heat can cause the bullet material to smear on the bore of the barrel. If the bullet material smears, it will leave a build-up of bullet material on the barrel. This residual bullet material, combined with residue from the primer and gunpowder, causes barrel fouling. Barrels must be cleaned and cared for to limit barrel fouling, since this build-up of residue can affect accuracy and performance and excessive build-up of material on the bore can increase pressure to a dangerous level. There are a number of factors that affect the amount of barrel fouling, including the bullet material or, if the bullet is jacketed, the jacket material. Guilding metal, which has copper as a main ingredient, is commonly used to jacket conventional lead bullets. Lead-free bullets may use a softer copper jacket to help reduce peak pressures if the alternative material lacks malleability (Patterson 2006b).

Barrel wear is the erosion of barrel material by the bullets and the heat and pressure generated by the burning propellant (Patterson 2006b). There are a number of factors that affect barrel wear including the hardness of the bullet or bullet jacket, malleability of the bullet material, the
construction of the bullet, and the hardness of the gun barrel.

Bismuth Cartridge Co. states that use of its bismuth ammunition will not cause more barrel-fouling than conventional lead ammunition and that use of its bismuth ammunition will not cause more barrel wear than conventional lead ammunition (Flaherty 2006).

According to one manufacturer, the copper used for solid copper bullets is softer than the copper alloy commonly used for jacketing of lead bullets. This manufacturer (Barnes) reduces barrel fouling by heat treating the bullets and by adding grooves to the bullet shank, which reduces fouling by
providing a relief area for displaced copper. Barnes states that any copper barrel fouling can be cleaned using ammonia-based cleaners (Barnes Bullets).

Remington states that the copper plating on its Disintegrator iron core bullets provides a smooth, ductile jacket that enhances feed and function in all auto-loading pistols, minimizes barrel fouling, and virtually eliminates barrel erosion (Remington Arms Company, Inc.). In its law enforcement ammunition catalog, Federal Cartridge Co. states that the heavy metal-free primer and lead-free bullets of its BallistiClean stranded zinc core ammunition help to reduce barrel fouling. The stranded zinc ammunition is plated with a copper jacket and therefore barrel wear is expected to be similar to other copper jacketed ammunition (International Cartridge Corp ).

Financial Assessment

Initial Purchase Price for Chemical/Alternative

Lead is significantly less expensive than any of the alternatives in this assessment, with the exception of iron. The Platts Metals Week North American producer price for lead was $0.65 per pound in December 2005. The dealer prices for bismuth fluctuated from an average of $3.55 per pound in the first quarter of 2005 to an average of $4.57 per pound in the fourth quarter of 2005. The 2005 fourth quarter price represented a 33% increase over the 2004 fourth quarter price. The December 2005 price for copper (U.S. producer cathode) was $2.23 per pound. Iron is not traded on an exchange (e.g. London Metals Market) but the price for hot rolled steel plate, which was $0.29 per pound in December 2005, suggests that the price of iron is competitive with lead. (Metals Consulting International (MCI) )Tungsten prices fluctuated from approximately $2.72 per pound in January 2005 to approximately $9.98 per pound in May 2005. (DesLauriers 2005) The Platts Metals Week (North American Special High Grade) price for zinc was $0.88 per pound in December 2005.

Initial Purchase Cost for End-product/Component
Ammunition with lead-free bullets or lead-free frangible bullets is marketed primarily to law enforcement agencies and the military and therefore consumer prices for lead-free handgun ammunition were not readily available.
A study conducted by the New Jersey Division of Criminal Justice found the following regarding the purchase price for reduced lead and lead-free ammunition(Zamrok 2004):

• Lead training ammunition was approximately half the cost of lead service ammunition
• Firing line safe training ammunition with lead-free primer and totally encapsulated lead core projectiles cost an additional $2 to $20 per 1000 rounds over lead training ammunition, depending on caliber and manufacturer
• Lead-free training ammunition (lead-free primer and projectile) cost $30 to $40 more than lead service ammunition per 1,000 rounds
• Frangible lead-free training ammunition cost $100 more than lead service ammunition per 1,000 rounds (9mm caliber)

A search of online ammunition retailers found that the cost of lead training ammunition for indoor shooting ranges (9mm, 115 grain, full metal jacket) varied from $0.14 to $0.20 per round. The cost of lead-free training ammunition (copper, copper/tin, iron, and tin/copper) was at least double that of lead training ammunition. The prices found for lead-free 9mm training ammunition ranged from $0.30 to $0.70 per round. In comparison, firing line safe training ammunition with lead-free primer and totally encapsulated lead core projectiles could be purchased for a 10-20% premium over lead training ammunition.

Winchester produces frangible handgun training ammunition (Ranger SF) that is composed of 90% powdered copper and 10% powdered tin with a non-toxic primer. The price of this product (9 mm caliber) is approximately 2.3 times the price of conventional lead training ammunition. Winchester
also produces lead-free training ammunition (Super Clean NT) that is composed of a solid tin core with a copper jacket. This ammunition is not frangible. The price of this product for a 9 mm handgun is about two times the price of conventional lead training ammunition (Nowak 2006).

Pricing for bismuth and tungsten ammunition was not available because they are sold only to law enforcement agencies.

Availability of Chemical/Alternative

Bismuth, and tungsten are relatively scarce metals with a limited reserve base, while copper, iron (steel) and zinc are more abundant than lead (European Commission Enterprise Directorate- General 2004).

All primary bismuth consumed in the U.S. is imported and less than 5% is obtained by recycling old scrap. Most bismuth is produced from mines in Mexico, China, Peru and Bolivia. It is a byproduct of processing lead ores, and in China, it is a byproduct of tungsten ore processing. Reported bismuth consumption was 2,120 metric tons in 2003 in the U.S. Worldwide demand is growing at about 5% per year, driven in part by its use as a replacement for lead but a global shortage is not expected. However, the supply could be constrained by low prices (Carlin, James F. Jr.).

In 2005, the worldwide mine production of copper was 16.4 million tons but strong growth in China and India resulted in a global production deficit. In 2006, increased capacity is expected to result in a modest production surplus (Edelstein 2006).

In 2004, worldwide trade in iron ore was approximately 670 million metric tons (Iron and Steel Statistics Bureau (ISSB)).

U.S. consumption of tungsten in 2005 was 11,600 metric tons. World tungsten supply is dominated by Chinese production and exports. The Chinese government regulates tungsten production and the total volume of tungsten exports, and the government has gradually shifted the balance of export
quotas towards value-added downstream tungsten materials and products. In 2005, inadequate supplies of tungsten concentrates within China combined with increased demand for tungsten materials in China and elsewhere resulted in steep increases in the prices of tungsten concentrates.
In response to this price increase, the sole Canadian tungsten mine restarted operations and action was taken to develop tungsten deposits or reopen inactive tungsten mines in Australia, China, Peru, Russia, the United States, and Vietnam (Shedd 2006).

Worldwide, there was a 200,000 ton production deficit of zinc in 2005. In 2005, U.S. mine production of zinc was 837,800 tons, which accounted for less than one-third of the quantity consumed domestically. Canada and Mexico are leading sources of imported zinc (Gabby 2006).

Availability of Component/End-product

Lead-free handgun ammunition is produced by each of the leading ammunition manufacturers and a few smaller ammunition manufacturers specialize in the production of lead-free ammunition. Currently, the primary market for lead-free handgun ammunition is for law enforcement and military training applications. A few manufacturers also produce lead-free duty rounds. Lead-free ammunition is available in both solid bullet and frangible bullet designs. The bullets made with hard metals (iron and tungsten) must be frangible or they would be classified as armor-piercing bullets.

Handgun ammunition with frangible bismuth bullets is available from at least one manufacturer, Bismuth Cartridge Co. This manufacturer currently only markets its Bismuth Reduced Hazard Ammunition to law enforcement agencies. It is available with conventional, lead-free, or heavy metal free primers. The company manufactures round nose training ammunition and is in the final stages of research and development of a hollow-point duty bullet (Flaherty 2006).

The Bismuth Cartridge Co. website lists the following frangible bismuth ammunition products: 9 mm 115 grain round nose; .40 S&W 135 grain flat point; and .45 Auto 185 grain flat point. A company spokesperson said that it can provide custom bismuth training ammunition that duplicates the trajectories and recoil of an agency’s duty load (Flaherty 2006). It also produces bismuth frangible duty rounds for applications where ricochet poses a hazard.

Several ammunition manufacturers produce handgun ammunition using bullets composed of a mixture of powdered copper and powdered tin, which is sintered to produce a frangible bullet. Copper is used by at least one manufacturer to produce solid copper bullets. Solid copper bullets are not frangible and are used for duty rounds, personal defense or hunting applications. Copper is also used as a jacketing material for many types of ammunition, including handgun ammunition with lead, bismuth, iron, and tin cores.

At least one ammunition manufacturer produces lead-free frangible handgun ammunition produced with iron powder. The projectile in Remington’s Disintegrator Lead-Free Frangible ammunition is composed of powdered iron with an electroplated copper jacket. Remington markets its Disintegrator product line to law enforcement agencies. Disintegrator ammunition is available in 9 mm, .40 S&W, and .45 ACP calibers.

Tungsten has been used recently for lead-free handgun ammunition but it could not be confirmed that it is currently produced by ammunition manufacturers. Winchester had produced handgun training ammunition with a tungsten/nylon bullet (Ranger DF) but this product was replaced by ammunition that uses a 90% copper/10% tin bullet (Ranger SF), which Winchester says is a better product. (Nowak 2006)Tungsten/nylon ammunition was used at the Massachusetts Military Reservation firing range at Camp Edwards from 1999 until February 2006, when its use was halted over concerns that tungsten was migrating into Cape Cod’s groundwater (Lehmert 2006).

Zinc is used by Federal Cartridge Co. in its BallistiClean handgun ammunition, which is marketed to law enforcement for training. The bullet used in BallistiClean ammunition has a stranded zinc core and a copper jacket (Federal Cartridge Company).

Table 3.4.1 C lists the ammunition manufacturers known to produce handgun training ammunition with lead-free bullets

Capital Costs

The lead bullet production process is significantly different from the production process used to produce frangible lead-free bullets. Production of lead bullets involves extruding a lead billet into wire, cutting the wire into slugs, and then pressing the slugs into the shape of a bullet. For jacketed bullets, a copper jacket is applied (National Research Council (NRC) 2004).

Frangible bullets made from powdered copper/tin or iron require a significantly different production process due to the fact that they are made from powdered metals. Bismuth frangible bullets are cast, swaged and then plated with a copper jacket (Bismuth Cartridge Company).

Due to the differences in production processes, it is likely that switching a lead bullet manufacturing process to a lead-free manufacturing process would require significant capital investment. It should be noted however, that most of the major ammunition manufacturers already market ammunition with lead-free bullets, which means that they have either already invested in lead-free bullet production or they purchase lead-free bullets from a supplier. An expansion of the market beyond current production capacity would likely require significant additional capital expense.

Key Operating Costs During Use of End-product

Use of lead ammunition increases a firing range’s operating costs since air monitoring and blood level testing of range officers must be conducted according to OSHA and EPA standards. Use of lead ammunition may also increase costs associated with maintenance of containment and filtration systems, purchase of replacement filters, range cleaning and hazardous waste disposal. By switching to lead-free ammunition, firing ranges can reduce or eliminate costs in these areas (Jones 2001; Massachusetts Division of Occupational Safety 2004).

Frangible bullets, including those made from bismuth, copper, iron and tungsten, fragment into dust when shot at mild steel targets, which reduces wear and damage to the targets, bullet traps and backstops at firing ranges.

Key End-of-Product Life Costs

Lead bullets and bullet fragments collected at indoor firing ranges are typically sold to lead recyclers and therefore may represent a source of revenue for firing ranges. At ranges where both lead and lead-free ammunition is used, certain types of lead-free bullets, such as zinc bullets, may contaminate the lead, making it unsuitable for recycling. (Vargas, 2004) Lead bullets may also be contaminated with other materials, such as materials used for bullet traps, which can decrease the recycling value or eliminate the possibility of recycling. Lead smelters separate the copper jacketing material from the lead and recycle it. Any lead that is not recycled must be disposed of as hazardous waste.

Bismuth, copper, iron, tungsten, and zinc bullets and bullet fragments collected at indoor firing ranges can be disposed of as non-hazardous material. These lead-free materials can also be collected for recycling. Information about the value of reclaimed bullets or bullet fragments made of these lead-free materials was not available but it should be noted that, with the exception of iron, the raw material prices for these alternatives are significantly higher than lead, which indicates the potential of higher values for the reclaimed materials.

A Department of Defense study estimated that the clean-up cost for a closed outdoor leadammunition firing range can be up to $2.5 million, while the average cost to clean-up an indoor lead ammunition firing range is about $150,000 (Anonymous 2001).

The following tables provide additional financial data for lead ammunition alternatives.

Table 3.4.1 D: Ammunition for Shooting Ranges – Bismuth

Table 3.4.1 E: Ammunition for Shooting Ranges – Copper

Table 3.4.1 F: Ammunition for Shooting Ranges – Iron

Table 3.4.1 G: Ammunition for Shooting Ranges – Tungsten

Table 3.4.1 H: Ammunition for Shooting Ranges – Zinc

Environmental Health and Safety

Numerous studies indicate that lead exposure can occur at shooting ranges where lead ammunition is used, particularly for range masters and instructors. The primary source of lead exposure is from the airborne lead particles and lead fumes released from the bullet during firing. When lead ammunition is used where the lead core is exposed at the base of the bullet, approximately 80% of the airborne lead comes from the bullet and the remaining 20% comes from lead styphnate in the primer and lead dust generated when the bullet hits the target (Noll, Clark 1997; Simpson 1993; Fischbein 1980).

Results from evaluations of exposures to lead in indoor law enforcement firing ranges by NIOSH showed that shooters had a mean lead exposure of 110 μg/m3 (8-hour, TWA) when firing lead bullets. Eighty nine percent exceeded the OSHA PEL for occupational exposure to lead (50 μg/m3, 8-hour, TWA) (Centers for Disease Control (CDC) 1983).

The National Association of Shooting Ranges (NASR) lists fifty-five handgun shooting ranges in Massachusetts, most of them with indoor shooting ranges. The handgun ammunition used at these ranges is almost exclusively ammunition with bullets made of lead and primer that contains lead and other heavy metals. A spokesperson from the Sporting Arms and Ammunition Manufacturers Institute (SAAMI) said that, to his knowledge, Massachusetts does not have any lead-free indoor firing ranges with the possible exception of those used by law enforcement and the military (Patterson 2006a).

Environmental Assessment

Drinking Water Standards

The National Primary Drinking Water Regulations are legally enforceable standards, set by EPA, that apply to public water systems. In these standards, the Maximum Concentration Level (MCL) for lead in drinking water is 15 μg/L and the Maximum Concentration Level Goal (MCLG) is zero. Copper is the only alternative ammunition material in this assessment for which EPA has set an MCL. Copper has an MCL of 1300 μg/L. EPA has also established National Secondary Drinking Water Standards, which are non-enforceable guidelines regulating contaminants that may cause cosmetic effects (such as skin or tooth discoloration) or aesthetic effects (such as taste, odor, or color) in drinking water. The following list shows the alternative ammunition materials included in these secondary standards:

• Copper: 1000 μg/L
• Iron: 300 μg/L
• Zinc: 5000 μg/L

Affinity for Water: Water Solubility

Lead, bismuth, copper, and iron are insoluble in water. Tungsten dissolves in water reaching concentrations up to 475 – 500 mg/L (Strigul, Nicolay et al. 2005). Zinc is soluble in water but the solubility is dependent on the properties of the water, such as acidity, temperature, chlorine concentration and hardness. It should be noted that certain compounds of these metals may be soluble.

Density

The density of lead is 11.34 g/cm3. With a density of 19.3 g/cm3, tungsten has the highest density of the alternatives in this assessment, followed by bismuth (9.8 g/cm3), copper (8.9 g/cm3), iron (7.8 g/cm3), and zinc (7.10 g/cm3) (Automation Creations).

Bioaccumulation

According to the International Chemical Safety Cards (ICSCs), bioaccumulation of lead may occur in plants and mammals and it is strongly advised that lead does not enter the environment. Specific information on the bioaccumulation of copper, tungsten, zinc, bismuth and iron were not available. As discussed in earlier in this report, EPA is in the process of developing a framework that will address the issue of bioaccumulation of metals, as well as related issues such as bioavailability.

Aquatic toxicity

National Recommended Water Quality Criteria was used as a source for data on aquatic toxicity of lead and lead-free alternatives. Water Quality Criteria includes the following two aquatic life criteria for both freshwater and saltwater:

• Criteria Maximum Concentration (CMC) – An estimate of the highest concentration of a material in surface water to which an aquatic community can be exposed briefly without resulting in an unacceptable effect.
• Criteria Continuous Concentration (CCC) – An estimate of the highest concentration of a material in surface water to which an aquatic community can be exposed indefinitely without resulting in an unacceptable effect.

Lead, copper and zinc are listed as Priority Toxic Pollutants and iron is listed as a Non Priority Pollutant. Bismuth and tungsten were not included in the Water Quality Criteria list. The following table shows the Water Quality Criteria for lead, copper, iron and zinc.

Table 3.4.1 I: Water Quality Criteria Comparison

The Water Quality Criteria values indicate that lead, copper and zinc are toxic to aquatic organisms, even at relatively low concentrations.

In 1994, EPA addressed the aquatic toxicity of alternatives to lead fishing sinkers in its response to citizens’ petition and proposed ban for lead fishing sinkers. In its assessment of aquatic toxicity of lead alternatives, EPA made the following statements about copper and zinc: “Laboratory studies indicate that copper is more toxic to aquatic organisms, such as fish, crustaceans, worms, and algae than lead.” (United States Environmental Protection Agency (USEPA) 1994). However, EPA believes that environmental conditions in freshwaters would mitigate the toxicity of copper to aquatic organisms. Zinc is more toxic to aquatic organisms (fish and crustaceans) than lead and it may be more bioavailable to aquatic organisms than lead. “Tungsten was found to have low toxicity to aquatic organisms (crustaceans and algae)” (United States Environmental Protection Agency (USEPA 1994). EPA stated that it did not find any information to indicate that bismuth or iron is toxic to aquatic species.

Human Health Assessment

Acute Human Effects: Occupational Exposure Limits

Lead exposure can occur at indoor shooting ranges from airborne lead particles and lead fumes released during firing. In general, the lead-free ammunition alternatives have less stringent occupational exposure limits than lead.

• IDLH

The Immediately Dangerous to Life or Health Concentrations (IDLH) for lead is 100 mg/m3. The IDLH for copper is also 100 mg/m3. There are no data on IDLH for bismuth, tungsten and zinc. For iron, the IDLH is 2,500 mg Fe/m3; 1-2 grams may cause death but 2-10 is usually ingested in fatal cases.

• PEL

(TWA) for copper is 1 mg/m3. The PEL for iron oxide is 10 mg Fe/m3. PELs have not been established for bismuth, steel, tungsten and zinc; however, PELs have been set for zinc chloride (1 mg/m3) and zinc oxide (5 mg/m3).

• REL

The Recommended Exposure Level (REL) for lead is 0.050 mg/m3 (TWA). The REL (TWA) for copper is 1 mg/m3; for steel (iron) is 5 mg Fe/m3; and for tungsten is 5 mg/m3. An REL has not been established for bismuth or zinc.

• TLV

The ACGIH TLV for tungsten is 5 mg/m3, for copper is 1 mg/m3, for iron oxide is 5 mg Fe/m3 (respirable fraction) and for zinc oxide is 2 mg/m3 (respirable fraction). ACGIH has posted a Notice of Intended Change for copper,; the new proposed TLV is 0.1 mg.m3 (inhalable fraction).

Acute Human Effects: Irritation

• Dermal: Lead and bismuth do not cause dermal irritation. Skin exposure to copper, iron, tungsten and zinc may cause dermal irritation.

• Ocular: Dusts of lead and all of the lead-free alternatives can cause ocular irritation, with the exception of zinc.
• Respiratory: Dusts of lead and zinc were not identified as respiratory irritants, while bismuth, copper, iron and tungsten can cause respiratory irritation.

Chronic Human Effects: Mutagenicity and Carcinogenicity

Lead is classified as both a mutagen and probable human carcinogen (IARC 2B). The lead-free alternatives in this assessment (bismuth, copper, iron, tungsten and zinc) are not classified as either mutagens or carcinogens.

Chronic Human Effects: Reproductive and Developmental Toxicity

Lead has been identified as a developmental toxicant in humans. Children are particularly sensitive to the chronic effects, which include slowed cognitive development and reduced growth. High lead exposure is also associated with reproductive effects, such as decreased sperm count in men, spontaneous abortions in women and low birthweight (United States Environmental Protection Agency (USEPA)

The lead-free alternatives in this assessment (bismuth, copper, iron, tungsten and zinc) have not been identified as reproductive or developmental toxicants.

Assessment Summary

Table 3.4.1 J summarizes the alternatives assessment information for lead ammunition.

3.4.2 Alternatives Assessment for Wheel Weights

Technical Assessment

Longevity/Life in Service

Wheel weights are installed on a vehicle’s wheels during the tire balancing process and they typically remain in service until the tire is rebalanced or replaced, or until the wheel or vehicle is retired from use. Wheel weights are not typically reused so their life in service is determined by the frequency of tire rebalancing, the life of the tire and the life of the vehicle.

Wheel weights do not typically wear out but they can “fly off” when a vehicle is jarred or during sudden velocity changes. Factors such as improper installation and damage from contact with curbs or other objects can also cause weights to fall off. It is estimated that the annual loss rate is 10%. (Root 2000)

None of the reports and studies reviewed suggested that the material used for the weights affected the life of the weights or was a factor in the rate that the weights fall off the wheels.

Key Standards for Component/End-product

Wheel weights must meet the vehicle manufacturers’ specifications before they can be used for Original Equipment Manufacturer (OEM) applications. OEM specifications can include the following: (Gearhart 2006b)

• Corrosion protection: Corrosion protection is a focus of OEM specs. The OEMs typically require specs such as salt corrosion testing, cyclic corrosion testing, and UV testing for fading.
• Physical dimensions: OEM specs limit maximum clearance dimensions (thickness, length, and width) to eliminate interference with other vehicle components and to prevent out-of-balance problems.
• Shape: Some OEM specs specify shape properties such as curvatures or labeling surfaces.
• Clip design: While the clip design is typically under producer control, the clip/weight assembly must meet specs such as clip gap and curl.
• Material: OEMs did not specify the weight material in the past but they are beginning to specify lead-free weights.
• Labeling: OEMs typically require labeling on wheel weights often including identification of the mass and material of the weight.

Aftermarket wheel weights are typically not required to meet OEM specifications.

Key Physical Characteristics & Performance Requirements

Density and Mass:

There are two common methods for attaching weights to wheels; clipping the weight to the rim of the wheel, and affixing the weight to the wheel using adhesive. For both wheel weight applications, a small weight size is desirable to prevent interference with other vehicle components, such as the brakes. Large weights are more visible and therefore less desirable, particularly for use on the outer rim of the wheel. Because density of the weight material directly influences the size of the wheel weight, it is a key physical characteristic.

All of the materials considered in this assessment are less dense than lead, which has a density of 11.34 g/cm3. With a density of 8.96 g/cm3, copper has the highest density of the alternatives in this assessment, followed by steel (7.87 g/cm3), tin (7.34 g/cm3), and zinc (7.10 g/cm3). (Automation Creations) The density of a zinc alloy (ZAMAC) used for wheel weights is 6.76 g/cm3. (Umicore )

The size (volume) of wheel weights made from copper, steel, tin and zinc must be larger than equivalent lead weights by 27%, 44%, 54%, and 60% respectively. Since the allowable thickness and width of wheel weights is limited, this increase in size is typically achieved by increasing the length of the weights. The mass of wheel weights used for passenger car applications typically ranges from 5 grams to 60 grams. (Hennessey Industries) Weights in this range are small enough that the increase in size (length) required for the alternative materials typically does not present problems. (Lohse, Sander & Wirts 2001)

Hardness:

Both clip-on weights and adhesive weights are mounted to curved surfaces of the wheel. Given the wide variety of wheel sizes and designs, it is desirable for wheel weights to be relatively soft and malleable so the curvature of the weight can be adjusted during installation to match the curvature of the wheel. (Lohse, Sander & Wirts 2001)Lead is a soft, malleable metal so it is relatively easy to make adjustments to the curvature of lead weights during installation with the use of a wheel weight hammer.

Lead has a hardness of 4.2 on the Brinell scale and a hardness of 1.5 on the Mohr’s scale, which makes it softer than all of the alternative materials except pure tin. Pure tin has a Brinell hardness of 3.9 but some tin alloys are harder than lead (ASTM B 23 has a Brinell hardness of 17). The following table lists the wheel weight materials in order of increasing hardness: (Automation Creations)

Table 3.4.2 A: Hardness of Wheel Weight Materials

Malleability:

Copper, and tin are relatively malleable and the curvature of wheel weights made of these materials can be modified, to some degree, during installation. Zinc and zinc alloy are significantly harder and less malleable than lead so it may be difficult to adjust the curvature of the weights during installation. In addition to being relatively hard, steel has limited malleability and therefore forming of weights during installation to match the wheel diameter is typically not possible. The use of steel and zinc weights may require the number of standard wheel weight shapes to be increased. (Lohse, Sander & Wirts 2001)

Melting Point:

Heat generated during braking can result in brake disc temperatures of up to 1300 degrees F. The maximum temperature at the wheel rim where clip-on weights are installed is approximately 250 degrees F, while the maximum temperature at the wheel where adhesive weights are installed is typically well below 400 degrees F. (Lohse, Sander & Wirts 2001) The melting points for copper (1980 deg. F), steel (2732 deg. F), tin (450 deg. F) and zinc (787 deg. F) are higher than the maximum temperatures wheel weights are exposed to. The melting point of lead is 622 degrees F. (Automation Creations)

Corrosion Resistance:

Wheel weights must be corrosion resistant due to the harsh environment which includes exposure to moisture, high temperatures and road salt. The wheel weights must not undergo galvanic corrosion when affixed to steel or aluminum wheels. All lead weights used for OEM applications have a coating to prevent corrosion but many of the aftermarket lead weights are not coated. (Gearhart 2006a) Uncoated lead weights will leave black marks when applied to aluminum wheels.

Copper, steel and zinc wheel weights require a coating in order to prevent corrosion. Copper has good resistance to atmospheric corrosion but it develops a protective coating that over time thickens to give a green patina, which would be unacceptable for wheel weight applications. Steel weights will rust if they are not coated and zinc weights must be coated to prevent galvanic corrosion when mounted on aluminum wheels. A manufacturer of tin adhesive wheel weights states that no corrosion protection is required for tin wheel weights and that they will retain a good surface appearance. (Trax JH Ltd.)

Shape and Configuration:

It is advantageous for wheel weights to be malleable so they can be shaped during installation to match different wheel diameters. Using on-malleable materials for clip-on weights would result in the need to increase the number of shapes/styles/sizes to match the wide variety of wheel designs and sizes. The design of adhesive weights can be modified to account for the limited malleability of the materials like steel. Adhesive weights made of soft malleable materials can be in the form of a bar, while weights made of harder, less malleable materials are constructed of separate small weights attached to a strip of adhesive tape. Partitioning the weight into segments allows for application to the curved diameter of the wheel. (Lohse, Sander & Wirts 2001)

Recyclability:

Lead weights are collected for recycling after they are removed from wheels during the rebalancing of tires. The tire dealers and auto service stations that balance tires typically collect lead weights and send them to secondary smelters for recycling.

EPA estimates that 16 million pounds of wheel weights are sent to secondary smelters. (USEPA 2005) EPA estimates that an additional 8 million pounds may be processed in automobile recycling. During the recycling of automobiles, lead weights must be removed from the wheels to avoid contamination of recycled materials and auto shredder residue (ASR). (Ecology Center 2005a)

Lead from used wheel weights is also used by individuals who make their own lead fishing sinkers and ammunition, who collect the used weights from tire dealers and service stations. EPA estimates that 0.8 to 1.6 million anglers make their own fishing sinkers. This activity has the potential to expose individuals and family members to airborne lead particles or vapors released during the pouring of molten lead into the fishing sinker molds. (United States Environmental Protection Agency (USEPA) 1994)

All of the alternative materials considered in this assessment can also be recycled. Copper can be recycled without any loss of quality and the value of copper provides an economic incentive for recycling. The unique color and appearance of copper weights would facilitate material separation.

Copper recovered from refined or re-melted scrap composed 30% of the total U.S. copper supply. (Edelstein 2006)

Steel is easily recycled and material separation may be easier with steel weights since they can be identified and sorted with the use of magnets. The clips for clip-on weights are also made of steel and therefore could be recycled along with the weight, eliminating the need for separation. Steel weights do not need to be removed from steel wheels during automobile recycling.

Tin and zinc weights resemble lead weights and are more difficult to sort and separate. The high cost of tin provides an economic incentive to recover weights for recycling. A German study estimated that, when vehicles are dismantled for recycling, tin weights would be removed from the vehicles’ wheels at a rate approaching 100% because the high price of tin would justify this procedure. (Lohse, Sander & Wirts 2001)

There is the potential that the challenge of separating lead-free weights from lead weights will result in a decline in the recycling of all wheel weights. (Ecology Center 2005b)

The following tables provide additional technical performance data for each of the alternatives.

Table 3.4.2 B: Wheel Weights – Copper

Table 3.4.2 C: Wheel Weights – Steel

Table 3.4.2 D: Wheel Weights – Tin

Table 3.4.2 D: Wheel Weights – Zinc

Financial Assessment

Initial Purchase Price for Chemical/Alternative

Lead is significantly less expensive than any of the alternatives in this assessment, with the exception of steel. In December 2005, the Platts Metals Week North American producer price for lead was $0.65 per pound. The December 2005 price for copper (U.S. producer cathode) was $2.23 per pound. For tin (Metals Week composite), the price was $4.43 per pound, and for zinc (Platts Metals Week North American Special High Grade), the price was $0.88 per pound. Steel is not traded on an exchange (e.g. London Metals Market) but the price for hot rolled steel plate, which was $0.29 per pound in December 2005, suggests that the price of steel is competitive with lead. (Metals Consulting International (MCI))

Initial Purchase Cost for End-product/Component

There are a variety of factors that affect the price of wheel weights including: material, weight, type, quantity in package, order size, vendor, and whether the weight is uncoated or coated. Wheel weights for passenger cars are available in a variety of weights, typically ranging from 0.18 oz. to 2.1 oz.

Clip-on wheel weights are available in a variety of different styles, where each style is designed to fit a specific wheel rim design. Wheel rim designs can vary by the vehicle year, make and model and wheel weight manufacturers often provide tire dealers with a chart that matches the wheel weight
style to the vehicle.. The wheel weight styles are designated by letter codes such as AW, EN, FN, LH, and MC. “P” type weights are generic weights for passenger cars and “T” type weights are for trucks. (Hennessey Industries)

For lead weights, the most significant price factor appears to be the coating. A coated lead weight can cost 2-3 times more than the uncoated equivalent. This can be illustrated using prices from an online auto parts retailer, Patchboy.com. The price for an uncoated 0.25 oz. AW type lead weight was $0.05, while the price for the coated version of the same weight was $0.16. The price for an uncoated 2 oz. AW type lead weight was $0.19, while the coated version of the same weight was $0.38. By contrast, the difference in price between the various types of weights is minimal. For example, for 0.25 ounce coated lead weights, there is a $0.01 difference between the AW type and the MC type. For the 2 ounce size, the prices for these two types are the same.

In a 2005 study, the Ecology Center of Ann Arbor, Michigan collected wheel weight price information from three retailers and three manufacturers located in North America, Europe and Japan. Price information was collected on clip-on lead weights (coated and uncoated) and clip-on coated steel and zinc weights. The Ecology Center made comparisons using the average price of weights from 0.25 – 2 oz. in size for each manufacturer and found that steel and zinc coated weights were comparable in price to lead coated weights. In some cases, lead-free weights could be purchased at a lower cost than high quality, coated lead weights. (Ecology Center 2005b)

The following table contains a cost comparison for lead, steel and zinc clip-on weights collected by the Ecology Center in 2005:

Table 3.4.2 E: Wheel Weight Cost Comparison

Copper weights are high quality coated weights and appear to be marketed to high end autos including Aston Martin. (Trax JH Ltd.) Although pricing was not available, it is expected that copper weights are significantly more expensive than lead weights based on raw material costs. Pricing for tin weights was not available. It is expected that tin weights are significantly more expensive than lead weights based on raw material costs.

Availability of Chemical/Alternative

The Ecology Center of Ann Arbor, Michigan has estimated that 70,000 tons of lead is used each year to manufacture wheel weights worldwide. However, the quantity of lead used for this application is decreasing as auto manufacturers are switching to steel and zinc weights.

In 2005, the worldwide mine production of copper was 16.4 million tons but strong demand in China and India resulted in a global production deficit. In 2006, increased capacity is expected to result in a modest production surplus. (Edelstein 2006)

Global crude steel output in 2005 was 1,129 million metric tons. (Iron and Steel Statistics Bureau (ISSB)) Increased production of steel wheel weights is not expected to affect supply or price of steel.

In 2005, the U.S. consumption of tin was 51,480 tons. Tin has not been mined in the United States since 1993. During the period of 2001-2004, the primary sources of imported tin were Peru (44%), China (14%), Bolivia (14%), and Indonesia (11%). World tin reserves appear to be adequate to meet foreseeable demand. Domestic demand for primary tin is expected to grow slowly in the next few years, at a rate of about 1% per year. That rate, however, could double in a few years if new applications, especially those in which tin is substituted for toxic materials, such as lead-free solders, find acceptance in the marketplace. (Carlin, James F. Jr 2006)

In 2005, there was a 200,000 ton production deficit of zinc worldwide. U.S. mine production in 2005 was 837,800 tons. Domestic zinc metal production capacity accounts for less than one-third of the quantity consumed domestically. Canada and Mexico are leading sources of zinc. (Gabby 2006)

Availability of Component/End-product

European and Japanese automobile manufacturers have switched to lead-free wheel weights and U.S. automobile manufacturers are currently in the process of making the switch. Most wheel weight manufacturers are now producing lead-free wheel weights to meet this demand. However, the aftermarket, which accounts for 80% of total wheel weight usage in the U.S., continues to use lead weights almost exclusively. (Gearhart 2006a) The following table lists the manufacturers known to produce lead-free wheel weights.

Table 3.4.2 F: Manufacturers of Lead-free Wheel Weights

Copper adhesive weights are available from at least one major wheel weight manufacturer but copper clip-on weights are not available. Copper is not currently being used in the U.S. for wheel weights by either the auto manufacturers or the aftermarket.

Steel wheel weights are available in both clip-on and adhesive styles. Steel is less dense than lead and therefore steel weights are larger than lead weights. As a result, size restrictions limit the availability of some steel weights. Steel weights are available for passenger vehicles which typically use .25 - 2 ounce weights. Trucks often require larger weights which may not be available in steel.

General Motors and Ford are in the process of converting to steel weights and it is expected that this conversion will be complete in 2006 and 2007 respectively. Asian auto manufacturers are currently equipping most of their vehicles with steel weights. (Gearhart 2006b)

The availability of tin wheel weights is very limited. Only one manufacturer (Trax) was identified as a producer of tin wheel weights and only in the adhesive style.

Many of the leading manufacturers of wheel weights, including at least two in North America, produce both adhesive and clip-on zinc weights. Zinc weights are available in a variety of sizes and types but the zinc product offerings are typically not as extensive as the lead product offerings. Zinc weights are used extensively in Europe. U.S. auto manufacturers are equipping new vehicles exported to Europe with zinc weights. (Ecology Center 2005a)

Capital Costs

A significant investment in production equipment is required to start-up production of lead-free wheel weights. Many of the major wheel weight manufacturers have already added lead-free wheel weight production capacity to meet the demand for lead-free weights from the auto manufacturers. However, manufacturers that supply the U.S. aftermarket must still produce lead weights to meet the ongoing demand for inexpensive weights. A shift by the aftermarket to lead-free weights would likely require manufacturers to make additional investments in capital equipment.

It is not known what the current production capacity is for lead-free weights or the capital costs required to convert lead weight production to lead-free weight production. It is also not clear whether one type of lead-free weight production process is more capital intensive than another.

Key Operating Costs During Use of End-product

Operating costs for lead-free wheel weights are expected to be the same as for the equivalent lead weights. Whether the lead-free weights are clip-on or adhesive weights, they are installed in the same manner as the equivalent lead weights.

Replacement Rate

The replacement rate of wheel weights is dependent on a number of factors, including the rate at which weights are lost, and the frequency of tire replacement. It is estimated that 10% of installed wheel weights are lost on an annual basis and the average lifespan of a tire is three years or 44,000 miles. (Ecology Center 2005b)

Key End-of-Product Life Costs

Lead wheel weights that are removed from wheels during tire balancing are subject to state and federal hazardous waste rules unless they are recycled. The lead waste is typically recycled at secondary lead smelters. The lead weights must be transported by licensed haulers, usually those that transport lead acid batteries. The removal and storage of lead weights for recycling may require special containers and recordkeeping. (Minnesota Pollution Control Agency (MPCA) 1998)

If lead weights are not removed from automobiles prior to automobile recycling and shredding, lead can contaminate other recyclable materials and the auto shredder residue (ASR). ASR contaminated with lead may be classified as hazardous waste. (Ecology Center 2005a)

Used copper, steel, tin and zinc wheel weights are not subject to state and federal hazardous waste rules and therefore waste management and recycling costs may be reduced. Steel, copper and zinc are widely used in automobiles so weights made from these materials are not likely to become contaminants in the automobile recycling process since they are recovered during the recycling process. The high value of scrap copper and tin provides an economic incentive for recovery and recycling.

The following tables provide additional financial data for each of the alternatives.

Table 3.4.2 G: Wheel Weights – Copper

Table 3.4.2 H: Wheel Weights – Steel

Table 3.4.2 I: Wheel Weights – Tin

Table 3.4.2 J: Wheel Weights – Zinc

Environmental Assessment

EPA estimates that 50 to 60 million pounds of lead are used each year to produce wheel weights in the United States. (United States Environmental Protection Agency (USEPA) 2005) In a 2003 study of the stocks and flows of lead wheel weights in the U.S., the U.S. Geological Survey (USGS) reported that approximately 56 million pounds of lead were used to produce wheel weights and approximately 130 million pounds of lead weights were in use on registered vehicles (Bleiwas, 2006).

This USGS study estimated that 4 million pounds of lead wheel weights were lost on U.S. roadways in 2003 and an additional 8 million pounds were unaccounted for. The study also estimated that 75 percent (28 million pounds) of lead weights removed from vehicles by tire retailers, repair shops and dealerships were recycled and 6 million pounds of lead wheel weights were recycled by automotive scrap dealers in 2003.

A study published in 2000 estimated that the fleet of cars and light trucks currently in operation in the U.S. contain 55 million pounds of lead wheel weights. (Root 2000)Root estimated that 10% of these weights (5.5 million pounds) fall off the vehicles each year with 3.3 million pounds being deposited on urban streets where much of it is ground into dust by automobile traffic. The study claimed that the residual lead dust can then be washed into waterways or sewers, migrate into nearby residential properties, or become airborne particulates. Wheel weights are also collected during street cleaning operations and then disposed of in municipal landfills.

Drinking Water Standards

The fate of wheel weights that fall off during use is not fully understood but the potential for wheel weight materials to contaminate groundwater, including drinking water supplies, exists. Some of the wheel weights that are deposited on streets and highways are collected by street cleaning operations and disposed of in municipal landfills. The acidic conditions in the municipal landfills can solubolize lead from the wheel weights, resulting in lead contamination of groundwater. (United States Environmental Protection Agency (USEPA)

The National Primary Drinking Water Regulations are legally enforceable standards, set by EPA, that apply to public water systems. In these standards, the Maximum Concentration Level (MCL) for lead in drinking water is 15 μg/L and the Maximum Concentration Level Goal (MCLG) is zero. Copper is the only alternative wheel weight material in this assessment for which EPA has set an MCL. Copper has an MCL of 1300 μg/L.

EPA has also established National Secondary Drinking Water Standards, which are non-enforceable guidelines regulating contaminants that may cause cosmetic effects (such as skin or tooth discoloration) or aesthetic effects (such as taste, odor, or color) in drinking water. The following list shows the alternative wheel weight materials included in these secondary standards (aluminum is used in the zinc alloy ZAMAC):

• Copper: 1000 μg/l
• Iron: 300 μg/l
• Zinc: 5000 μg/l
• Aluminum: 20-500 μg/l

Florida and Minnesota have established maximum concentration levels for tin in drinking water (4200 μg/l and 4000 μg/l respectively). Arizona set the maximum concentration level for copper at 1300 μg/l.

Affinity for Water: Water Solubility

Lead, copper, steel and tin are insoluble in water. Zinc is soluble in water but the solubility is dependent on the properties of the water, such as acidity, temperature, chlorine concentration and hardness. It should be noted that certain compounds of these metals may be soluble.

Density

All of the materials considered in this assessment are less dense than lead, which has a density of 11.34 g/cm3. With a density of 8.96 g/cm3, copper has the highest density of the alternatives in this assessment, followed by steel (7.87 g/cm3), tin (7.34 g/cm3), and zinc (7.10 g/cm3). (Automation Creations) The density of a zinc alloy (ZAMAC) used for wheel weights is 6.76 g/cm3. (Umicore)

Bioaccumulation

According to the International Chemical Safety Cards (ICSCs), bioaccumulation of lead may occur in plants and mammals and it is strongly advised that lead does not enter the environment. Specific information on the bioac