Maine Addresses Lead Wheel Weights

Approximately 13 percent of wheel weights fall off and can collect on curbsides where they degrade and impact water quality (see http://ehp.niehs.nih.gov/docs/2000/108p937-940root/abstract.html). Maine has tested parking lot runoff and found levels of lead that exceed toxicity levels for aquatic wildlife. According to the May 2000 article in Environmental Health Perspective at the National Institute for Environmental Health Science (NIEHS) link provided above, wheel weights could be one of the sources of this lead.

Maine DEP approached the state fleet managers, who were open minded about exploring less toxic wheel weight options, and the Maine State Transportation Department (ME DOT) volunteered to lead the program. ME DOT has been actively researching alternative wheel weight products and their availability and piloting several alternatives, including steel. In July of 2006, the state’s fleets are likely to begin conversion to different wheel weight materials on lightweight trucks and passenger vehicles as products become available. Maine has contracts with several hundred private garages to service state vehicles. State personnel plan to specify that lead-free weights be used, if available. The fleet manager from the state university system has also been brought into the discussion.

ME DEP will build on the experience of the state fleets to develop and distribute outreach materials on less toxic wheel weight products. Materials will be distributed to garage contacts with which the state collaborates on various pollution prevention projects.

The ME DEP staff learned that conversion of wheel weights on larger vehicles is a research project for a longer period of time. The necessary large size for a steel wheel weight, due to the lower density of steel over lead, on a truck or school bus tire would pose a safety concern if the weight falls off. Several internal weighting systems are on the market, limited use is occurring, and progress with this product will be followed.

Maine school buses frequently use lead wheel weights. A number of school fleets have begun to use an alternative weighting product; and one large private school bus contractor has abandoned the use of the internal weighting product. One of the alternative wheel weight materials is zinc. Maine will not promote the use of zinc wheel weights since zinc has wildlife toxicity concerns (though less so than lead).

The European Union is working towards eliminating the use of lead wheel weights, and multiple car manufacturers are producing models with alternative wheel weight products.