Use Nationally and in Massachusetts
In the U.S the major use of Cd compounds is Cd hydroxide used in the manufacture of nickel-Cd batteries. Other uses include manufacture of pigments (as Cd selenide and Cd sulfide), coatings and plating solutions (as Cd fluoroborate, Cd iodide, Cd oxide, and Cd sulfate), and stabilizers for plastics (as Cd oxide, Cd laurate, and Cd stearate).
Overall, Massachusetts has experienced a 73% reduction in the use of cadmium and cadmium compounds since 1990.
Batteries: Nickel Cd is currently the most widely used Cd battery, and accounts for nearly all of the Cd used in batteries. This amounts to approximately three-fourths of the total Cd used in the United States. Silver Cd is also used in batteries for aircraft and space applications.
Pigments: Cadmium pigments account for approximately 12 percent of the Cd used in the United States. More than 85 percent of Cd pigments are used in plastics applications. Other uses of Cd pigments include paints, ceramic ware, glass, and decorative coatings for metals, printing inks, and rubber.
Polymer Stabilizers: Cadmium salts of long-chain fatty acids, such as Cd carboxylate, Cd laurate, and Cd stearate, have traditionally been used as heat and light stabilizers in polyvinyl chloride (PVC). However, use of Cd stabilizers has decreased in the United States as other viable and less toxic alternatives, such as barium-zinc, calcium-zinc, and organotin stabilizers have become available.
Coatings and Plating Solutions: About 8 percent of the Cd used in the United States goes into metal coatings and plating solutions. Cadmium coatings are applied to steel products such as aircraft landing gear components, automotive brake parts, fasteners of all types, and springs. In addition, Cd coatings have been widely used on electrical and electronic components, such as connectors, equipment housings, and switches. Cadmium usage for coatings and plating solutions in the U.S. has been greatly reduced since the 1960s, and especially in the 1990s, due to restrictions placed on industries by the U.S. EPA for their use of Cd.
New uses for Cd in the synthesis of ultrathin photovoltaic films comprised of Cd selenide (CdSe) and Cd telluride (CdTe) nanocrystals are currently being developed.
Between 1990 and 2005 total U.S. Cd consumption declined by 76%. During the same period, Massachusetts’ manufacturers followed the national trend experiencing a 73% reduction in the overall use of Cd and Cd compounds since 1990.
Table 1 summarizes the use of Cd and Cd compounds in Massachusetts by industry sector, based on TUR reporting data from Massachusetts companies. For the purpose of assessing trends, industry sectors are aggregated into three use categories - Plastics and Resins Manufacture, Metal Products Manufacturing, Wire and Wiring Device Manufacture and Electroplating.
Cadmium uses and their trends of use in Massachusetts for each of the categories are depicted in Figure 1, and described below.
Since 1960, the national trends in Cd use have showed rapid growth in NiCd batteries, slow decline in coatings and pigments, and faster declines in all other use categories. NiCd batteries accounted for more than half of the rechargeable battery market in the mid-1990s but since then, the use of NiCd battery technology has begun to decline. In 2006, Cd use in batteries amounted to 82% of apparent consumption, followed by pigments, coatings, plating, stabilizers for plastics, nonferrous alloys, photovoltaic devices, and other. Additional details on current uses of Cd and Cd compounds follow.
Plastics and Resins Manufacture
Uses of Cd and Cd compounds in the plastics and resins sectors are associated with stabilizer additives and pigments in plastic and synthetic products. Plastics formulators in Massachusetts, including manufacturers of custom resin formulations, and manufacturers of plastic products such as sheet and film plastic, eliminated their reportable uses of Cd between 1990 and 2005 (as of 2002 no company reported using greater than 10,000 pounds of Cd or Cd compounds in any one year).
Suitable substitute additives and pigments were identified and used by Clariant Corp Master Batches Division within 4 years of initial reporting. While AlphaGary continued to manufacture custom polymer compounds containing Cd until 2002, it reduced its use of Cd compounds 70% by 2003. It reduced its use of Cd by over 97% within the first year of reporting.
Both manufacturers of plastic film and sheet discontinued their operations prior to 2005. Regalite Plastics Corp curtailed operations in Massachusetts by 1999. Vernon Plastics Company discontinued operations in 2002.
Wire and Wiring Device Manufacture
American Insulated Wire Corp used plastics containing Cd compounds in 1990 only. This company, which manufactures electrical and electronic wire, cable and cord set products, serving a variety of markets, continues to manufacture products, but was able to reduce its use of Cd compounds below the reporting threshold within one year of reporting.
Checon Corporation began operations in Massachusetts in 2004. Checon supplies electrical contact materials for a variety of applications, including industrial control, electrical switch, wiring device, appliance, and automotive. Its use of Cd compounds increased over 17% from 2004 to 2005.
Metal Products Manufacturing
Cadmium is used in low melting point and brazing alloys with bismuth, lead and tin. Cadmium containing alloys are used as bearings, solders and copper hardeners in fire detection devices, high-speed machinery, automotive components and nuclear reactor control rods.
Alloy manufacturing industries in Massachusetts include nonferrous rolling and drawing, primary metal products, and motor vehicle parts and accessories. Products manufactured by companies in Massachusetts within these industry sectors include:
- Silver powder and Cd oxide bars
- Silver Cd alloy forming and casting
Engineered Materials Solutions (EMS) began its cold-rolled metal cladding operations in 2000, after separating from its parent company, Texas Instruments. EMS began operations using Cd compounds to manufacture platinum-clad contact terminals in 2001. This operation has had relatively constant use of Cd compounds since that time.
Of the companies who ceased using reportable amounts of Cd by 2005, one company, BASF Catalysts LLC (formerly Engelhard Corp) reported that it had ceased its manufacturing operations by 1993. The second company (Metalor Technologies USA) employed product reformulation techniques to bring its use of Cd below reporting thresholds.
Production processes conducted in the electroplating sector include Cd electroplating and Cd cyanide electroplating.
Between 1990 and 2005, Cd use in electroplating applications decreased by 43% in Massachusetts. This decrease was due primarily to the elimination of Cd-cyanide electroplating operations at the Texas Instruments facility in Attleboro in 2000.
New Method Plating Corp, a job shop operation that does custom electroplating for various customers, has continued its use of Cd electroplating operations fairly steadily over the course of the reporting period. It is common for job shop operations to feel that moving towards safer alternatives is out of their control and instead a function of their customer demands. However other companies have had success in educating their customers about safer viable alternatives, thereby affecting toxics use reduction through changing customer demands.
Companies Entering the Reporting Universe
The TURA Science Advisory Board (SAB) designated Cd and Cd compounds as a higher hazard substances under TURA in January 2008. This designation reduces the reporting threshold for Cd and its compounds to 1,000 lbs/year. TURI anticipates that the number and quantity of Cd and Cd compounds reported for use in subsequent years will therefore increase.
In the resins, pigments and plastics sectors, it is likely that a small percentage of the many Massachusetts companies continue to use cadmium colorant compounds in amounts over the 1,000 pound threshold. TURI estimates that there may be as many as 30 new cadmium compound filers, primarily in SIC 3089 (Plastic Products) and SIC 3087 (Custom Compounded & Plastic Resins), reporting their use of Cd in 2008.
Inputs and Outputs in Massachusetts
The change from 1990 to 2005 in absolute amount of inputs and outputs in Massachusetts is shown in Figure 2. Inputs include Cd and Cd compounds that are processed or “otherwise used” – ancillary uses that do not become incorporated into the final product. No Cd or Cd compounds are manufactured in Massachusetts above reportable quantities.
Outputs include Cd and Cd compounds that are generated as byproducts (i.e., all non-product material created by a process line prior to release, on-site treatment, or transfer) and the amount of Cd and Cd compounds that are shipped in or as products.
The majority of Cd and Cd compounds used is processed and subsequently shipped in products. Though some data was reported as being “otherwise used”, it is likely that this was in error, as the company reporting this way later reported only processed uses.
As shown in Figure 2, the amount of Cd and Cd compounds in the Massachusetts economy (i.e., inputs and outputs based on TURA reporting data) has been significantly reduced overall in the Commonwealth from 1990 to 2005. Specifically, from 1990 to 2005, the amount of Cd and Cd compounds processed was reduced by 73% and the amount of Cd and Cd compounds otherwise used was reduced by 100%. The amount of Cd shipped in products was reduced by 90% and the amount generated as byproducts was reduced by 70% over the same time period.
Endnotes: Butterman, 2002; U.S. Department of the Interior. U.S. Geological Survey, 2006 Minerals Yearbook: Cadmium and U.S. Geological Survey, Mineral Commodity Summaries 2007: Cadmium; Massachusetts Toxics Use Reduction Act data. 2007; Toxics Use Reduction Institute, Summary of Policy Analysis, Higher Hazard Substance Designation Recommendation: Cadmium (CAS # 7440-43-9) and Cadmium Compounds.