One of the most common hazards in an industrial environment is noise. It is also one of the most frequently ignored by workers. The danger of long term noise exposure is not as obvious as a fall or a saw blade, but without effective preventative measures it will still result in debilitating damage in the long term.

According to National Institute for Occupational Safety and Health (NIOSH) 22 million workers are exposed to potentially damaging noise each year. It is important that employers have a program that will control the length and intensity of the amount of exposure that their employees receive. Per OSHA guidelines there are three components to an effective program: Recognition, Evaluation, and Control.

Recognition

The first step is any safety program is understanding the undeniable threats of hazardous noise. Noise is measured in decibels (dB), which is on a logarithmic scale, so the amount of noise generated doubles every 10 dBs. So 60 dB is twice as loud as 50, 70 twice as loud as 60, and so on. Measuring the noise level can be done a few different ways, but the two most common types of instruments are sound level meters and noise dosimeters.

Sound level meters measure sound at a particular moment. Since the OSHA standard is based around a weighted average, these are most useful for doing preliminary surveys to find areas where the limit is exceeded.

For areas that are identified, a noise dosimeter can then be worn by an employee for their entire shift. The meter will continually measure the decibel exposure and will report at the end of the shift the wearers weighted average exposure.

So what are the limits? According to OSHA, 90 dBs is the highest level of “safe” noise exposure when averaged over an eight hour period. Any employee who would exceed that limit must be provided with control measures to reduce their exposure back under 90 dB.  There is also an “action level” at 85 dB. An employee whose exposure hits 85 must be provided with a Hearing Conservation Program, which is covered more in depth below.

Evaluation

Once the need is identified, the next step in creating a program is evaluation. The way to measure an employee’s hearing level is audiometric testing, also called a hearing test. OSHA requires that testing be done when the threat is identified for current employees so that a baseline can be established. That needs to be done within six months of identifying a 85+ dB hazard. After it is identified all new employees who will work in that area should be tested upon hire.

Once a baseline is established, tests should be performed annually. Testing can only be performed by a licensed or certified audiologist or technician who has been certified by the Council of Accreditation in Occupational Hearing Conservation. The purpose of these tests is to see if there is any hearing loss, or standard threshold shift. All testing records should be kept for the duration of an employee’s time with the company, and likely should be kept after they leave as well to protect the company against potential lawsuits.

A loss of hearing is defined as a change in the hearing threshold of an average of 10dB or more in either ear. If that occurs, then OSHA requires that the employee be re-instructed on the proper usage of PPE, fitted properly with hearing protection, and required to wear their protection. This leads into the third component of a program, which is control

Control

When it comes to controlling the exposure to hazards, the process follows the same guidelines. As outlined in our previous post about the three lines of safety defense, the first two options are engineering controls and administrative controls. For noise, examples of effective engineering controls would be installing noise absorbing or reducing work environment, investing in machinery that would make less noise, or isolating the source of the sound. Administrative controls could involve changing the job functions so that there is less exposure or rotating employees from high to low noise areas. Both of these methodologies are more effective than PPE, which is why they come first for OSHA.

If a feasible administrative or engineering control is not available, then PPE is the next solution. There are two broad types of hearing protection, earmuffs and ear plugs. Make sure to take note of the NRR rating of each, as that will be instructive in which is needed. The NRR is subtracted from the measured exposure level, and the result must be below 90dB.

PPE is only as effective as the way it is worn, and far too often employees do not wear their hearing protection properly. This can be attributed to a lack of training or a lack of variety. Ears come in all shapes and sizes, so it is important for employers of offer a variety of options so that employees can select the PPE that fits them best.

Employers should also provide regular training on the importance of hearing protection and how to properly wear it. In the video below a Martin representative showcases how to put in an ear plug to achieve maximum protection:

 

Conclusion

Hearing is something that does not come back, once the cochlea or the auditory nerves are damaged they do not recover, so preservation of hearing is something that is vitally important. Maintaining a strong hearing conservation program is key to making sure that employees are not exposed to unsafe levels of noise and are protected for their future wellbeing. To review, here are the most important parts of an effective program.

• Conduct Noise Exposure Monitoring
• Perform Audiometric Testing on Employees Regularly
• Provide A Variety of PPE to Employees
• Conduct Employee Training
• Keep Records of All Program Activity

If you have further questions contact Martin today and speak with one of our safety specialist and learn more about checkups and keeping your hearing safe.