Back to Basics is a weekly feature that highlights important but possibly overlooked information that any EHS professional should know. This week, we examine noise exposure and OSHA’s recommendations for exposure reduction.
All of the human senses must be protected from hazards and damage in the workplace, including hearing. According to OSHA, the CDC estimates that about 22 million employees are exposed to potentially damaging noise at work every year. Reducing hazardous noise exposure and providing hearing protection are two crucial steps employers must take to protect a worker’s ears and to prevent hearing loss.
Hearing loss is preventable, so no matter what the workplace, reducing noise exposure must be a priority. OSHA says that if a worker must raise their voice to speak to someone three feet away, noise levels might be over 85 decibels (dB). Noise hazards may be present in your workplace if workers:
- Hear ringing or humming in their ears when they leave work
- Have to shout to be heard by a coworker and arm’s length away
- Experience temporary hearing loss when leaving work
There are several instruments that measure sound and noise levels that should be made available in a workspace, including level meters, noise dosimeters, and octave band analyzers. The National Institute for Occupational Safety and Health (NIOSH) Sound Level Meter App is one tool available to the public that measures sound in the workplace and provides noise exposure parameters to help reduce occupational noise-induced hearing loss. This app can be downloaded on mobile iOS devices.
The standards for noise hazards are covered in OSHA’s standards for recordkeeping and general industry. The basic requirement for recordkeeping is that if an employee’s hearing test, the audiogram, reveals that the employee has experienced a work-related Standard Threshold Shift (STS) in hearing in one or both ears, and the employee’s total hearing level is 25 dB or more about audiometric zero in the same ear(s) as the STS, the employer must record the case on the OSHA 300 Log.
Exposure to high levels of noise can cause permanent hearing loss, which neither surgery nor a hearing aid can help correct. Short-term exposure to loud noise can also cause a temporary change in hearing, like when a worker’s ears feel stuffed up, or tinnitus, which is a ringing in the ear.
These short-term issues, according to OSHA, might go away within a few minutes or hours after exposure to the noise. Repeated exposures to loud noise can lead to permanent tinnitus and/or hearing loss. Noise-induced hearing loss can limit an employee’s ability to hear high frequency sounds, understand speech, and seriously impair their ability to communicate.
Additionally, loud noise can create physical and psychological stress, reduce productivity, interfere with communication and concentration, and contribute to workplace accidents and injuries by making it difficult to hear warning signals for other hazards.
Exposure and controls
According to OSHA, exposure to noise is measured in units of sound pressure levels called decibels, using an A-weighted sound levels (dBA). There are multiple ways to control and reduce worker exposure to noise in a workplace where exposure is excessive, including engineering and administrative controls.
Engineering controls for noise hazards involve modifying or replacing equipment, or making related physical changes at the noise source or along the transmission path to reduce the noise level at the worker’s ear. The following are some inexpensive, effective engineering controls:
- Choose low-noise tools and machinery
- Maintain and lubricate machinery and equipment
- Place a barrier between the noise source and the employee, like sound walls or curtains
- Enclose or isolate the noise source
Administrative controls, in this case, are changes in the workplace or schedule that reduce or eliminate worker exposure to noise. Machinery should be operated during shifts when fewer people are exposed, and the amount of time a person spends at a noise source must be limited. Employers should also provide quiet areas where workers can gain relief from hazardous noise sources. Controlling noise exposure through distance is often a simple, effective, and inexpensive administrative control, and for every doubling of the distance between the source of the noise and the worker, the noise is decreased by 6 dBA.
Hearing conservation program
As per OSHA’s standard, employers are required to implement a hearing conservation program in their workplaces. The goal of hearing conservation programs is to prevent initial occupational hearing loss, preserve and protect remaining hearing, and equip workers with the knowledge and hearing protection devices necessary to keep themselves safe.
Employers must measure noise levels, provide annual hearing exams, hearing protection, and training. They must also conduct evaluations of the adequacy of the hearing protectors in use, unless changes made to tools, equipment, and schedules result in worker noise exposure levels that are less than 85 dBA. Research suggests that workplaces with appropriate and effective hearing conservation programs have higher levels of worker productivity and a lower incidence of absenteeism.
For more information on workplace noise exposure, click here.