WASHINGTON — A 3-year-old federal agency ruling that liquid styrene may be a carcinogen still stands, according to the latest review of the decision.
Essentially an audit of the previous study, the U.S. National Academy of Sciences (NAS) released its review of the June 2011 U.S. National Toxicology Program’s (NTP) last week.
The committee that penned the original report found “limited but credible” evidence of carcinogenic effects from styrene in human studies, “sufficient” evidence from animal studies and “convincing relevant information” in studies observing DNA damage in human cells that had been exposed to styrene. According to the NAS, the committee reached the same conclusion after conducting both a peer review of the 12th Report on Carcinogens from 2011 and an independent assessment of the styrene literature from the past several years, through November 2013.
At least two studies of plastics workers exposed to styrene released in 2013 concluded that there is no connection between cancer and styrene exposure, even in high doses.
The original report sent shockwaves through parts of the plastics industry, with companies scrambling to change their material data sheet and beef up protection for employees while simultaneously pushing Congress to review the decision and the science behind it.
“Consumers are not at risk from products made from styrene. National Toxicology Program officials confirmed the safety of styrene-based products when styrene was included in its Report on Carcinogens in 2011,” said Jack Snyder, SIRC’s executive director. “The styrene industry has invested more than $25 million to advance the science on styrene and fulfill our product stewardship mission. We believe research currently in progress will expand on the data considered in the NRC report, and provide more robust information for future styrene hazard and risk assessments.”
Styrene is a liquid that can be chemically linked to create polystyrene, which is a solid plastic that displays different properties, which the ACC explained in a blog post.
“In light of the recent National Academy of Sciences review of styrene, it is important to point out that federal regulators have not changed their view that polystyrene is safe for food service packaging. The U.S. Food & Drug Administration, the agency charged with scientific review and approval of food contact applications, has determined for more than 50 years that polystyrene is safe for use in food service products. The European Commission/European Food Safety Authority and other regulatory agencies have reached similar conclusions,” the ACC said in a statement.
In addition to being a key component in the manufacture of polystyrene, colorless liquid styrene is also used in the manufacture of rubber tires, building insulation, carpet backing and reinforced fiberglass composites and occurs naturally in many foods, from strawberries to cinnamon.