OSHA requires a hearing conservation program to be in place when workers are exposed to noise levels of 85 decibels (dB) and above. Examples of hearing protection devices include ear plugs or ear muffs.  Hearing loss is often ignored because it can happen gradually over a period of time. The use of personal listening devices, such as ear buds or headphones, cannot take the place of hearing protection.

Some examples of equipment at UVM that may require hearing protection are sonicators, cage washers, and powered groundskeeping equipment.  A risk assessment should be conducted before appropriate hearing protection is chosen.


hearing protection: headphones, earplugs

Noise Reduction Ratings

Hearing protection devices receive a Noise Reduction Rating (NRR). This is the measurement, in decibels, of how well a hearing protector reduces noise as specified by the EPA.The higher the NRR number, the greater the noise reduction. While wearing hearing protection, your exposure to noise is equal to the total noise level minus the NRR of the hearing protectors in use. OSHA and NIOSH have developed different methods of "derating" the NRR based upon the type of hearing protection being used, as well as the type of noise it is used for.

Permissible Exposure Limits (PEL)

The limits for permissible noise exposure, according to OSHA standards, are shown in the table below. Short-term noise exposure should be limited to a level not greater than 115 dBA. Risk Management & Safety is available to monitor noise levels, as requested.

PELs for Noise According to OSHA:

8 hours 90 dB
6 hours 92 dB
4 hours 95 dB
3 hours 97 dB
2 hours 100 dB
1.5 hours 102 dB
1 hour 105 dB
30 min 110 dB
15 min 115 dB