OSHA Regulations

Who must be tested

You must offer hearing tests to all of those exposed to 85 dBA or more on an 8-hour time weighted average (TWA). The employer must notify each employee exposed to 85 dBA or more of noise monitoring results. Any employee exposed to more than 90 dBA on an 8-hour TWA must be provided hearing protectors to reduce the noise to 90 dBA 8-hour TWA or less.

Training

Employers must annually train employees exposed to an 8-hour TWA of 85 dBA in the following: (1) effects of noise on hearing; (2) purpose of hearing protectors; and (3) the purpose of hearing testing.

Baseline Audiogram

The employer must conduct a baseline hearing test for an exposed employee within 6 months of employment, or 1 year if using mobile testing. The baseline test must be preceded by 14 hours of non-noise exposure or the wearing of hearing protectors.

Annual Audiogram

After obtaining the baseline, the employer must annually conduct hearing tests for those exposed to 85 dBA TWA.

Standard Threshold Shift (STS)

A Standard Threshold Shift occurs when there is a change in the average of the 2000, 3000, and 4000 frequencies of 10 dBA or more in either ear. Allowance for aging (presbycusis) may be made.

You have 30 days to retest an STS, and may substitute the retest for the original.

You must perform these tasks when an STS occurs:

Notify the employee in writing of the STS within 21 days of the test.
For those not wearing hearing protectors, fit them with hearing protectors and train them in their use and care.
For those wearing hearing protectors, refit the protectors and retrain the employees in their use and care.
Refer for clinical evaluation any employees for whom addition testing is necessary or for whom the wearing of protectors causes a medical pathology.
Notify any employees of the need for an otological examination if a medical pathology is suspected that’s unrelated to wearing hearing protectors.
Employees who’ve had an STS must be provided hearing protectors that attenuate the exposure to an 8-hour TWA of 85 decibels or less.

Baseline Revision

An annual audiogram may be substituted for the baseline when in the judgment of an audiologist the STS revealed by the audiogram is persistent or if the audiogram indicates significant improvement of the baseline.

Recordables

An employee is considered potentially recordable when that employee has an STS and a non-age corrected average of 25 dB or more in the 2000, 3000, and 4000 Hz frequencies.

You do not have to record such cases if you plan a retest within 30 days of the test with a shift. If a retest confirms the recordable shift, you have 7 calendar days to record it on the 300 Log.

If subsequent testing shows the shift to be non-persistent, the 300 Log entry may be lined off.

Confirmed or persistent recordable shifts may be presented to an audiologist to determine work-relatedness. If the shift is deemed non-occupational, it may be lined-off the 300 Log.

Recordkeeping

Noise exposure measurements must be kept for two years; audiometric tests for the duration of the employee’s employment. All records must be provided to employees or former employees upon request.