Hearing loss in the workplace isn't always caused by noise. A category of chemicals known as ototoxicants can also damage hearing, often without employees realizing they're at risk until symptoms appear.
In many workplaces, employees are exposed to airborne chemicals while also working near noise-generating equipment. Combined exposure to noise and certain chemicals can damage the delicate structures of the inner ear, and in some cases contributing to hearing loss.
Understanding this risk is an important part of a workplace hearing conservation program.
Ototoxicity, as it's formally known, occurs when certain chemicals damage the auditory system, damaging the tiny hair cells in the inner ear or the auditory nerve. This damage can result in various hearing problems, from a slight muffling of sounds to significant hearing impairment.
Common ototoxic substances include: heavy metals like lead and mercury, certain solvents, pesticides, carbon monoxide, and tobacco smoke. Medications can also be ototoxic. A number of prescription and over-the-counter drugs have been associated with potential inner ear damage. Some of these medications require a prescription, while others can be purchased over the counter. Most of them are essential for treating various conditions, like cancer or infections. Chemotherapy drugs, specific antibiotics, and even something as common as aspirin is among the medications linked to hearing loss. Because many of these drugs are necessary for treating serious conditions, awareness and not avoidance is the appropriate response.
Awareness is the first step toward prevention. Whether you're an employer, an employee, or simply someone who cares about their health, understanding the potential risks associated with ototoxic chemicals is a solid starting point. Utilizing protective gear, ensuring proper ventilation, and following safety guidelines are key components of an effective hearing conservation program.
Exposure to ototoxic chemicals can be harmful and occur through various routes, including inhalation, ingestion, and skin absorption. The health effects caused by these ototoxic chemicals can vary depending on factors such as the frequency, intensity, and duration of exposure, as well as workplace exposure to other hazards and individual factors like age. These effects may be temporary or permanent, impacting hearing sensitivity and potentially resulting in a Standard Threshold Shift (STS), as defined under OSHA's Occupational Noise Exposure standard, 29 CFR 1910.95.
Workers can encounter these chemicals in different ways, including breathing them in, consuming contaminated food or drinks, and absorbing them through the skin by touching. Once these chemicals enter the body, they can travel through the bloodstream and cause damage to the inner ear and the nerves responsible for transmitting information to the brain.
Be vigilant for any signs and potential side effects. You might immediately notice signs of ototoxicity upon exposure to the chemical, or symptoms may gradually appear over time. Ototoxicity can even manifest symptoms up to five years after initial exposure. Typically, the first indication is the perception of sounds that others cannot hear, such as the persistent ringing in your ears (known as tinnitus). Other signs and symptoms may include:
Regular check-ups and monitoring are crucial, especially if you work in an environment where chemical exposure is a daily occurrence. If you notice any of the symptoms above, consult a healthcare professional. Early detection and intervention can make all the difference in preventing permanent hearing.
SafeLink Consulting helps businesses evaluate hazard communication as well as chemical and noise exposure together as part of a comprehensive hearing conservation program. Learn more about our OSHA compliance services and how we can support your workplace safety program.