On June 11, 2015 the natural products industry periodical WholeFoods Magazine published an article on the chemical styrene (CAS 100-42-5) and its possible listing as a carcinogen in California, U.S.. Polystyrene, made from the monomer styrene, is widely used in food packaging, e.g. in yogurt containers and foam packaging. The State of California has filed a notice of intent to add styrene to the Proposition 65 list of carcinogens. Under Proposition 65, also known as “The Safe Drinking Water and Toxic Enforcement Act of 1986”, chemicals that increase the risk of cancer, birth defects or other reproductive harm in humans are listed in California. California businesses must disclose the use of any chemical on that list to the public, unless it is present below a certain exposure level that is considered safe. If no safe exposure level is established, products exposing consumers to styrene, such as polystyrene food packaging, are required to be labeled with a warning.
A recent study concluded that the risk of genotoxicity of styrene oligomers migrating from polystyrene food packaging into food is low (FPF reported). New York City has banned polystyrene foam used for food containers as of July 2015 (FPF reported) because there is no economical recycling (FPF reported).
WholeFoods Magazine (June 11, 2015). “Styrene, used in packaging, may be added to Prop 65 list.”