The styrene industry is suing the state of California to prevent the state from adding a chemical used in polystyrene foam coffee cups and take-out food containers to its Proposition 65 list of chemicals known to cause cancer or birth defects. The state, which has some of the country’s most stringent consumer-protection laws, thinks the chemical is hazardous enough to both workers and the general public to warrant inclusion on the list, while the Styrene Information and Research Center, the industry group filing the complaint, thinks they’re overreacting.
THE DETAILS: Styrene is a chemical used in a number of plastics. It’s most common use is in polystyrene foam containers, coffee cups, and Styrofoam insulation, but it’s also used in the kind of plastic used to make Legos, bike helmets, water-filter pitchers, food processors, and a number of other plastic products. If the chemical were to be added to its Proposition 65 list, all these products that are sold in California would need to bear the warning label “This product contains chemicals known to the State of California to cause cancer and birth defects or other reproductive harm.”
The controversy over styrene comes in part from the fact that some research groups, such as the International Agency for Research on Cancer, have deemed it a “probable carcinogen”; others, including the U.S. Environmental Protection Agency, disagree. Calling the chemical a “probable carcinogen” means that there haven’t been any studies showing a link to cancer in people, but scientists have evidence that it can damage human cells to the point of causing cancer. The chemical also poses a serious health risk to workers exposed to it. Respiratory problems and a condition called “styrene sickness,” characterized by headaches, fatigue, and feelings of drunkenness, are common in occupational settings.
However, product testers haven’t found many instances where consumers are actually exposed to the chemical, and that might alarm people unnecessarily if they were to read warning labels like the ones required on products sold in California. A study published in the journal Food and Chemical Toxicology found that styrene did in fact leach out of polystyrene foam food containers and cups when the food (or coffee) inside was hot, but it didn’t leach out of foam egg cartons, which are generally kept cold inside refrigerators. The National Sanitation Foundation (NSF), an independent nonprofit that certifies products like water filters for their safety and efficacy, similarly found that styrene doesn’t leach out of hard plastics.