“CASQA acknowledged the evidence against tires is circumstantial,” he said.
Zinc is used in so many applications, including detergents and cosmetics, that it is difficult to identify any single source of zinc pollution, according to Mr. Van Genderen. “In Germany, 80 percent of the zinc problem comes from legacy mining,” he said. “But it's difficult to find deep pockets to go after in that case.”
The search for alternatives to zinc oxide in tires has been going on for many years, for various reasons, Mr. Van Genderen said.
One alternative is lead oxide, which obviously is unacceptable, he said. Calcium oxide and magnesium oxide are also alternatives, but are more effective for rubbers such as latex.
Mr. Van Genderen said the IZA has had a meeting with Mr. Allen's office and coordinated activities with the Rubber Manufacturers Association. An RMA spokesman said the association has relayed its concerns about the bill to Mr. Allen.
“We'll be working to educate other California legislators on this issue and believe that the bill will attract opposition from other groups,” the RMA spokesman said.
The California Senate Committee on Environmental Quality has scheduled an April 6 hearing on SB 1260, said the spokeswoman for Mr. Allen. If it passes, the bill will advance to the Judiciary Committee, which has until April 22 to consider it.
Tire and rubber product manufacturing is the single largest market for zinc oxide. Stefan Schlag of IHS Chemicals said at the recent Zinc Oxide Conference that global demand for zinc oxide in 2015 was 1.5 million metric tons, of which 830,000 tons came from the rubber industry.