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.
The U.S. Environmental Protection Agency (EPA) created a maximum contaminant action level for lead in drinking water of 0.015 mg/l. EPA has not established an inhalation reference concentration (RfC) or an oral Reference Dose (RfD) for elemental lead or inorganic lead compounds. EPA has, however, established an RfD for tetraethyl lead of 1 x 10-7 mg/kg body weight per day.
The following occupational threshold limits have also been established:
NIOSH Recommended Exposure Limit for an 8 to 10 hour time-weighted-average
exposure = 0.10 mg/m3.
- NIOSH Immediately Dangerous to Life or Health = 100 mg/m3.
- OSHA Permissible Exposure Limit for an 8 hour work day = 0.5 mg/m3.
- ACGIH Threshold Limit Value = 0.5 mg/m3 over an 8 hour work shift.
Restrictions on Lead in Products
There are various restrictions on the use of lead in products that have been promulgated by some international, national and state agencies. These include:
The European Union’s RoHS directive restricts the use of lead in many electronics applications if present in a homogenous material in amounts exceeding 0.1% by weight.
In the US, the Consumer Products Safety Commission (CPSC), under the Federal Hazardous Substance Act, has banned most “paint and surface coatings containing more than 0.06% lead, and furniture, toys and other articles intended for use by children that are coated with such paint.”
In addition, any toy or article intended for use by children that is likely to expose the child to a sufficient amount of lead to present a hazard, according to CSPC’s rules, is banned.
Several states in the Northeast have banned the use of certain lead sinkers for fishing. Massachusetts still allows the use of lead fishing sinkers except in the Quabbin and Wachusett Reservoirs.
In light of recent disclosures of lead in paint on children’s toys, in children’s jewelry, in vinyl products such as lunch boxes and bibs, and in lipsticks, there is growing concern about the need for more comprehensive regulations, testing and enforcement of lead restrictions in consumer products.
Endnotes: National Institute for Occupational Safety and Health (NIOSH) 2004, Pocket Guide to Chemical Hazards; U.S. EPA, National Ambient Air Quality Standards, http://www.epa.gov/air/criteria.html.