Effective April 22, 2016, the California Office of Environmental Health Hazard Assessment (OEHHA) added styrene to the Proposition 65 list of chemicals known to cause cancer. Styrene’s listing has been in the pipeline for many years based on formal identification by the National Toxicology Program (NTP) that the chemical is “reasonably anticipated to be a human carcinogen.” Concurrently with the listing, OEHHA also proposed a No Significant Risk Level (NSRL) for styrene of 27 micrograms per day. Comments on the proposed NSRL are due by June 6, 2016.

What is Styrene?

Styrene is a building block chemical that is used to make many different materials. The major plastic products that use styrene in the manufacturing process include:

  • PS, or Polystyrene
  • EPS, or Expandable Polystyrene
  • ABS, or Acrylonitrile Butadiene Styrene Copolymer
  • SAN – Styrene Acrylonitrile Copolymer
  • UPR, or Unsaturated Polyester Resins
  • SBR, or Styrene Butadiene Rubber

These materials are used to make everything from building products like carpet and insulation to consumer products like electronics and packaging materials. We all encounter these materials in our day to day lives.

How Should Manufacturers Address This?

Now that the listing is final, manufacturers of products that may contain styrene have one year to determine if their products could cause significant exposure to styrene and take appropriate action. Products that can cause styrene exposure greater than the No Significant Risk Level (NSRL) will be required to reformulate or provide a warning label.

How can UL help?

UL’s testing and toxicology expertise are a valuable asset for manufacturers trying to understand the implications of this listing on their business. Contact us today at environment@ul.com or call 888.485.4733.