LOS ANGELES (AP) — California is considering asking tire manufacturers to look at ways of eliminating zinc from their products because studies have shown the mineral, which is used to strengthen rubber, may harm waterways, it was announced Tuesday.

The state Department of Toxic Substances Control will begin preparing “a technical document for release in the spring” and will seek public and industry comment before deciding whether to create new regulations, the agency said in a statement.

On its website, the agency said its rulemaking process could take up to a year.

The concern is that zinc from tire treads will wash into storm drains and wind up in rivers, lakes and streams, harming fish and other wildlife.

The department’s move follows a petition by the California Stormwater Quality Association to add tires containing zinc to priority products list under the state’s Safer Consumer Products Regulations program.

The association is composed of federal, state and local organizations, school districts, water boards and more than 180 cities and 23 counties that manage wastewater, according to the organization’s website.


“Zinc is toxic to aquatic life and has been detected at high levels in many waterways,” Department of Toxic Substances Control Director Meredith Williams said in a statement. “Stormwater agencies make a compelling case for studying ways to control that.”

That could include requiring manufacturers to identify alternatives to using zinc in their tires.

The U.S. Tire Manufacturers Association said zinc oxide plays “a critical and irreplaceable role” in making tires that can carry weight and stop safely.

“Manufacturers have tested a variety of other metal oxides to replace or reduce the use of zinc but have not found a safer alternative. Without the use of zinc oxide, tires cannot meet federal safety standards,” an association statement said.

The association also said adding zinc-bearing tires to the state’s list “will not achieve its intended purpose” because tires typically account for less than 10% of the zinc in the environment compared to about 75% that comes from other sources.

“Zinc is found naturally in the environment and is contained in many products including galvanized metal, fertilizer, paint, batteries, brake pads and tires,” the association said in urging a “collaborative, holistic approach” to dealing with the problem.