October is National Protect Your Hearing Month, an annual event sponsored by the Centers for Disease Control and Prevention (CDC) to raise awareness about hearing protection. Hearing loss is one of the most common occupational illnesses, with work-related causes accounting for one quarter of overall hearing loss in the US. The CDC estimates that 22 million workers are exposed to potentially damaging noise at work each year.
Hazardous noise levels in the workplace are a serious concern that, if not protected against, can not only result in permanent hearing loss, but can also contribute to other causes of physical and mental stress as well as lower work productivity.
The two primary sources of occupational hearing loss are mechanical noise and ototoxic chemicals (or chemicals that can damage parts of the ear). The good news is that occupational hearing loss can be prevented if the sources are identified, and exposure is mitigated.
How do you determine if your workplace may have sources of exposure that could contribute to occupational hearing loss? For ototoxic chemicals, these can be identified by conducting a complete inventory review and having a system in place to assess the hazards of incoming chemicals. A Job Safety Analysis (JSA) can also be conducted to first identify exposure points and then the hierarchy of controls can be implemented to mitigate the hazards. Solutions may include replacing ototoxic chemicals with less toxic chemicals, improving ventilation, training employees to safely handle chemicals, and providing the appropriate personal protective equipment (PPE).
For mechanical sources, according to the National Institute for Occupational Safety and Health (NIOSH), if you must raise your voice to speak to someone an arm’s length away in any area of your facility, the noise levels may be loud enough to cause hearing loss. NIOSH has developed a Sound Level Meter (SLM) App that can be downloaded on mobile iOS devices and used to measure noise levels as an initial screening.
There are also several sound-measuring instruments that are available for a more comprehensive assessment of noise levels. These include sound level meters, noise dosimeters, and octave band analyzers. The choice of a particular instrument and approach for measuring and analyzing occupational noise depends on many factors, such as the purpose for the measurement and the environment in which it will be made.
The Occupational Safety and Health Administration (OSHA) specifically requires employers to implement a hearing conservation program whenever employee noise exposure equals or exceeds an 8-hour time-weighted average (TWA) sound level of 85 decibels (dBA). The OSHA permissible exposure limit (PEL) for noise is 90 dBA as an 8-hour TWA. As the decibels increase, the allowed exposure time rapidly decreases.
If noise levels are determined to be high, how can they be reduced? As we mentioned for ototoxic chemicals, exposure to mechanical noise can also be controlled following the hierarchy of controls. Options may include replacing noisy machinery with quieter alternatives, adding equipment enclosures, rotating duties to decrease exposure time, and providing proper PPE (e.g., earmuffs, earplugs).
To learn more about National Protect Your Hearing Month, or for information on noise monitoring and determining whether a hearing conservation program may be needed at your workplace, please contact us.
This blog was written by Sara Evarts, CIH, Safety Partners’ Associate Director, Industrial Hygiene.
