Styrene and Human Health

Since 1987, SIRC has undertaken a comprehensive research program to enhance understanding of the potential of styrene to affect human health, as well as the fate and effects of styrene in the environment. SIRC's approach has been to sponsor new research in areas where deficiencies and limitations in the existing data have not provided definitive conclusions. SIRC also commissions independent reviews of the health effects studies on styrene where data already exist. Research studies and literature reviews are sponsored with the intention that the final reports will be published in peer-reviewed journals.

SIRC worked closely with the U.S. Environmental Protection Agency's (EPA's) Office of Research and Development (ORD) and the National Toxicology Program (NTP) in developing protocols for its unique sub-chronic and chronic animal inhalation studies of styrene, and periodically has updated ORD on the progress of these and other studies. Based on the importance EPA placed on these studies, the Agency waited until 2002 to formally launch its hazard assessment for styrene for the Integrated Risk Information System (IRIS) database program. This review will determine whether styrene should be classified as a carcinogen and, if so, at what level. SIRC has continued to submit data for ORD's consideration during the course of this review.

While much of SIRC's work has focused on addressing styrene's carcinogenic potential, researchers also have investigated styrene's potential neurotoxicity, reproductive and developmental toxicity, mutagenicity, and genotoxicity, as well as its potential to be an environmental pollutant. The following sections review the scientific data on styrene for a variety of health and environmental effects endpoints. Because these sections merely summarize the scientific research, specific references to studies or publications are limited. Additional information on many of the studies mentioned may be found under Summary of Research and Our Journal: The SIRC Review. More information on specific references also may be obtained by contacting SIRC.