The U.S. Department of Health and Human Services (HHS) on June 10 added the common plastic-resin diluent, styrene, to its list of 240 chemicals and biological agents that may put people at increased risk for cancer. Styrene was one of eight substances added to the 12th HHS Report on Carcinogens (RoC). The change in styrene’s status affects the composites industry because this substance is released into the air during many open molding operations, particularly when sprayup methods are used.
According to the report, a congressionally mandated document that is prepared for the HHS secretary by the National Toxicology Program (NTP), styrene is on the list based on human cancer studies, laboratory animal studies and mechanistic scientific information. The limited evidence of cancer from studies in humans reportedly shows lymphohematopoietic cancer and genetic damage in the white blood cells, or lymphocytes, of workers exposed to styrene.
Chemical and composites organizations, in anticipation of the listing, petitioned HHS to keep styrene off the list. Their reactions to the report were swift and universally negative. “We are very disappointed that the National Toxicology Program failed to address the styrene industry’s and Congress’ legitimate concerns in its 12th Report on Carcinogens,” said Monty Felix, president of the American Composites Manufacturers Assn. (ACMA, Arlington, Va.). “It is the position of ACMA, as well as leaders in the scientific community, that styrene does not pose a cancer risk. European Union scientists recently completed an exhaustive review of styrene’s health effects and concluded that exposure to styrene is not likely to cause cancer in humans — a conclusion validated by myriad peer-reviewed studies in the United States.” Other federal agencies, including the Occupational Safety and Health Admin. (OSHA) and the Environmental Protection Agency (EPA), are aware of the data on the possible styrene/cancer link and, Felix pointed out, have not concluded that there is sufficient risk to require additional regulatory protections.
Editor’s note: CT’s guest commentator Tom Hedger, president of Magnum Venus Plastech (Kent, Wash.), addresses the future implications of the HHS determination for the composites industry in this issue’s “Composites: Past, Present & Future.” See link at right.