The Styrene Information and Research Center (SIRC) reports that a new study called Cancer Mortality of Workers Exposed to Styrene in the US Reinforced Plastics and Composite Industry, published in the journal Epidemiology, shows nearly 16,000 styrene-exposed workers in the U.S. composites industry have “no credible evidence that styrene exposure increases risk from cancers of the lymphatic and hematopoietic tissue, pancreas, or lung.”

“This study, published by the prestigious journal, Epidemiology, is further evidence that the NTP’s 12th Report on Carcinogens listing styrene as a ‘reasonably anticipated carcinogen’ is based on flawed science,” says ACMA Chief Staff Executive Tom Dobbins. As the result of hard work by ACMA and other groups, like SIRC, there is now Congressional support for a National Academy of Sciences peer review of NTP’s decision. We will continue to work on behalf of the composites industry in support of sound science, which clearly shows that exposure to styrene is not linked to cancer in humans.”

According to Jack Snyder, executive director of the Washington, D.C.-based SIRC, these new findings based on 60 years worth of epidemiology data on cancer risks associated with workers exposed to high levels of styrene, completely undercut the U.S. National Toxicology Program’s (NTP) listing of styrene as “reasonably anticipated to be a human carcinogen” in its 12th Report on Carcinogens (RoC).

“This updated analysis substantially adds to the evidence that indicates a lack of association between styrene exposure and cancer,” says Julie Goodman Ph.D., DABT, a toxicologist with Gradient Corporation. The new study adds additional weight to recent expert reviews by Texas and European Union regulators concluding styrene does not pose a cancer risk for humans.

On February 19, the American Composites Manufacturers Association (ACMA) sent a letter to a National Academy of Sciences (NAS) peer review panel in which ACMA Chief Staff Executive Tom Dobbins encouraged the panel to “clarify the current confusing situation”, regarding the carcinogenic potential of styrene, caused by the NTP listing.

SIRC also submitted a lengthy summary and analysis of scientific data to the NAS peer review panel arguing that an evidence-based interpretation of the toxicology and human data strongly indicates that styrene is not a human carcinogen. Further, SIRC maintains that the styrene data does not satisfy any of the NTP’s three listing criteria for classification as a “reasonably anticipated carcinogen,” nor is NTP’s RoC evaluation consistent with a scientifically valid evaluation of the data.

The NAS styrene panel will hold its first public meeting on March 19, 2013, and is expected to issue its peer review report in 2014.