DIVINYL BENZENE

OSHA comments from the January 19, 1989 Final Rule on Air Contaminants Project extracted from 54FR2332 et. seq. This rule was remanded by the U.S. Circuit Court of Appeals and the limits are not currently in force.

CAS: 108-57-6; Chemical Formula: C₆H₄(HC=CH₂)₂

Previously, OSHA had no limit for divinyl benzene. The ACGIH has a TLV-TWA of 10 ppm, based on this substance’s similarity to styrene. The proposed PEL was 10 ppm as an 8-hour TWA, and NIOSH (Ex. 8-47, Table N1) concurs with this limit. In the final rule, an 8-hour TWA of 10 ppm is promulgated for divinyl benzene. The commercial grade of divinyl benzene is a pale-straw-colored liquid; it contains all three isomers, but the meta isomer predominates.

The oral LD(50) for rats is reported to be 4.1 g/kg, and an acute inhalation study showed no ill effects from a single seven-hour exposure at 351 ppm. However, repeated or prolonged contact with the liquid may cause skin burns (Dow Chemical Company 1977j, as cited in ACGIH 1986/Ex. 1-3, p. 228).

Industrial experience indicates that irritation of the respiratory system, skin, and eyes can result from inhalation exposures to divinyl benzene, but there are no data concerning chronic exposures in humans. No comments, other than those of NIOSH, were received on divinyl benzene.

The final rule establishes a PEL of 10 ppm (8-hour TWA) for divinyl benzene. The Agency concludes that this limit will protect against the significant risk of irritation to the respiratory tract, eyes, and skin; such irritation constitutes a material impairment of health within the meaning of the Act.