Standard Interpretations - Table of Contents
• Standard Number: 1910.95

April 10, 1986

Dr. B. Pfeiffer
Berufsgenossenchafliches Institute
Fur Arbeitssicherheit
Lindenstrasse 80 Postfach 2043
5202 St. Augustin 2 Federal Republic of Germany

Dear Dr. Pfeiffer:

This is in response to your inquiry of July 23 concerning the Occupational Safety and Health Administration's (OSHA) standard for occupational noise exposure. We apologize for the delay in responding.

The standard was first issued on April 17, 1971. On March 8, 1983, it was expanded by adding provisions (c) through (p), called the "Hearing Conservation Amendment." It is mandatory for employers to comply with the standard. OSHA enforces it by conducting unannounced inspections and issuing citations if employers are found not to be in compliance. A copy of the standard is enclosed.

The standard limits employee noise exposure in accordance with a 5-dB exchange rate. Specifically, a 5-dB increase in sound pressure level is permitted for each halving of duration of exposure. It is not permissible to expose any employee in excess of the 90-dBA criterion, which means that no employee may be exposed to the equivalence of a constant sound pressure level of 90 dBA for more than 8 hours, or to the equivalence of a constant sound pressure level 95 dBA for more than 4 hours, and so on.

Employers must make audiometric tests available to employees whose exposure exceeds an 85-dBA criterion, which means that tests must be made available where the exposure to the equivalence of a constant sound pressure level of 85-dBA lasts more than 8 hours, exposure to the equivalence of a constant sound pressure level 90 dBA last more than 4 hours, and so on. Any employee whose audiogram reveals a standard threshold shift (STS), as defined at (g)(10) of the standard, may not be exposed in excess of the 85-dBA criterion.

Employers must use feasible engineering and administrative controls to eliminate employee exposures in excess of the 90-dBA criterion. If the feasible engineering and administrative controls are not fully effective, the