The National Institute of Occupational Safety and Health should conduct its own weight-of-evidence hazard evaluations and not rely on inapplicable classifications by other organizations, argued ACMA in comments submitted to the Institute on February 12. ACMA also called on industry members to visit the association’s Advocacy Center and learn how they can help prevent yet another incorrect and misleading classification of styrene safety.

NIOSH, part of the Department of Health and Human Service’s Centers for Disease Control, recently proposed to classify as occupational carcinogens those substances listed as carcinogens by the National Toxicology Program, the International Agency for Research on Cancer and EPA. Both NTP and IARC classify styrene as a carcinogen based a few unrepresentative positive studies.

Styrene provides a productive example of the need for careful evaluations using weight-of-evidence assessment procedures recommended by the National Research Council, according to ACMA’s comments. Contrary to the findings of NTP and IARC, none of the several weight-of-evidence styrene assessments raised a cancer concern for this substance.