One of the most common chemicals used in composites manufacturing is styrene. Most of the styrene used to manufacture composite products is consumed in the chemical reaction that creates FRP, but a small amount of residual styrene can remain in the final products.

This issue has led to a challenge that many composites manufacturers face today: compliance with California’s Prop 65 regulation. Also known as The Safe Drinking Water and Toxic Enforcement Act of 1986, Prop 65 was passed with the goal of protecting drinking water sources from toxic substances that may cause cancer and birth defects, as well as reducing or eliminating exposure to them.

Even after 30 years, Prop 65 remains politically controversial because many believe it puts the burden of proof on businesses instead of the government to make a key scientific determination about safety levels for specific toxic chemicals. According to the California EPA (CalEPA), Prop 65 has “increased public awareness about the adverse effects of exposures to listed chemicals” and “provided an incentive for manufacturers to remove listed chemicals from their products.” However, although the regulation may have allowed Californians to make better-informed purchasing decisions, it has come at a cost for companies doing business in the state.

Prop 65 regulates toxic substances by placing any chemical that the state decides has a 1-in-100,000 chance of causing cancer or birth defects over a 70-year period on a special list. Last year, CalEPA’s Office of Environmental Health Hazard Assessment (OEHHA) ruled to add styrene to the list. That means that if a business manufactures, distributes or imports products containing styrene that are sold in California it may have to provide toxicity warnings on those products.

However, there are two exemptions to the rule. Warnings are not required for companies with fewer than 10 employees. Additionally, if a company can show that average daily lifetime exposures associated with use of its product are below what is known as the “No Significant Risk Level” (NSRL) for styrene, which is 27 micrograms per day of exposure, warning labels are not necessary. But because of the way that Prop 65 is enforced, manufacturers that don’t provide warnings can still be the target of expensive litigation even if they believe the styrene exposure associated with their products is below the NSRL. “Failure to warn” law suits as a result of Prop 65 can be expensive, even when resolved in the companies’ favor.

According to ACMA’s research, most composite products are theoretically exempt from the warning requirements because the styrene exposures associated with use of the products may be below the NSRL. However, the association believes that it is important for all composites manufacturers to mitigate any potential risk by taking steps now to develop customized risk management strategies that take potential enforcement and market losses into account.  Every company must review the regulation and their own activities and make a decision based on their specific situation. Additionally, ACMA suggests that companies may also want to seek legal counsel to help them make the best decision.