The Occupational Safety and Health Administration (OSHA) has published a Safety and Health Information Bulletin warning that exposure to certain chemicals can cause hearing loss.

According to the agency, research has shown that exposure to chemicals known as ototoxicants can lead to hearing issues as well as balance problems regardless of noise exposure. These chemicals - which can be found in some solvents, pesticides, and pharmaceuticals - can affect the way the ear functions. 

"Chemicals that can damage nerve fibers and tiny hairs within the ear are ototoxicants," explains Strom & Associates."Ototoxicant chemicals that affect hearing or balance can be found in many common products, including those that are used or spilled on construction worksites, factories, or in the home." 

These chemicals can reach the inner ear through the bloodstream and damage the parts of the ear as well as its connected neural pathways.

The risk of hearing loss is even greater when exposure to these chemicals is combined with higher noise levels. Hearing loss may be permanent or temporary depending on the length of the exposure, the dose of the chemical and the noise level. 

According to Safety and Health Magazine, OSHA has grouped these chemicals into five categories: solvents, pharmaceuticals, nitriles, asphyxiants, compounds, and metals.

Several industries have a higher risk of exposure to ototoxicants, including agriculture, mining, construction and utilities. Several subsectors of the manufacturing industry are also at risk, including metal workers, textile workers, painters, and workers who build ships and boats.

All forms of hearing loss can be devastating, but OSHA warns that speech discrimination dysfunction, a type of hearing impairment, is particularly dangerous. The affected worker cannot distinguish warning signals or voices from ambient noise.

OSHA highlights the concerns of ototoxicant-induced hearing loss among health and safety professionals, as hearing tests cannot distinguish between noise-induced and ototoxicant-induced hearing impairment. 

The first step in preventing exposure to ototoxicants is to determine whether they are in the workplace. Employers can start by reviewing OSHA's Safety Data Sheets to find ototoxic substances and/or chemicals.

Additionally, employers must provide health and safety training and information to workers who are exposed to hazardous materials, including ototoxic chemicals.

Exposure can also be reduced by replacing hazardous chemicals with less toxic chemicals. If it's not possible to remove ototoxicants from the workplace, it may be possible to use engineering controls, such as enclosures and isolation, to control exposure to noise and ototoxicants. Wearing the appropriate clothing can also reduce exposure risk, as ototoxic chemicals can be absorbed through the skin.