on the Regulatory Treatment of Styrene
In 1987 the International Agency for Research on Cancer (IARC) in Lyon,
France upgraded styrene's classification from a Group 3 "not classifiable"
to a Group 2B "possibly carcinogenic to humans." This reclassification
resulted from revisions to IARC's classification system; no new data prompted
the reclassification. It is important to note that IARC specifically states
that its classifications are intended for hazard
identification only, and should not be used for regulatory purposes.