Exposure to certain chemicals may cause hearing loss, OSHA warns

Washington — Ototoxicants – chemicals that can cause hearing loss and balance issues when inhaled, ingested or absorbed through the skin – are found in certain pesticides, solvents and medications, and the risk of their adverse effects increases when workers are exposed to elevated noise levels, OSHA cautions in a Safety and Health Information Bulletin published March 8.

OSHA groups ototoxic chemicals into five categories – pharmaceuticals (including analgesics and antibiotics), solvents, asphyxiants (including tobacco smoke and carbon monoxide), nitriles, and metals and compounds. Industries with higher exposure risk to ototoxicants include agriculture, construction, mining and utilities. Manufacturing industry subsectors at risk include fabricated metal workers, textile and apparel workers, painters, and ship- and boat-building workers.

OSHA notes that one particular type of hearing loss – speech discrimination dysfunction – is especially hazardous because the affected worker cannot distinguish co-workers’ voices or warning signals from ambient noise. Also problematic is that hearing tests do not distinguish between noise- and ototoxicant-induced hearing loss, and that “research on ototoxicants and their interactions with noise is limited.”

OSHA recommends that employers explore whether ototoxic chemical exposure may play a role in worker complaints of hearing loss, and if the Hierarchy of Controls can help reduce worker exposure.