Comparison of daily noise exposures in one workplace based on 3-dB vs 5-dB exchange rates and criteria recommended by the ACGIH versus OSHA

In May 1994, the American Conference of Governmental Industrial Hygienists (ACGIH) recommended as a threshold limit value (TLV) for noise exposure an 8-h equivalent level of 85 dBA, based on a 3-dB exchange rate. The U.S. Department of Labor’s Occupational Safety and Health Administration (OSHA) requires that employees be included in a hearing conservation program (HCP) if their 8-h time-weighted average (TWA) noise exposure equals or exceeds 85 dBA based on a 5-dB exchange rate. To investigate the number of additional employees who would be included in the HCP at one industrial facility if the ACGIH TLV were used, new personal dosimetry samples were collected for all noise-exposed employees. Employees at this facility have low noise exposures characterized by time-varying or intermittent noise and impact components. To allow analysis of each sample using both exchange rates, each monitored worker wore either two single-setting dosimeters or one double-setting dosimeter. Based on this data the potential impact if OSHA changed its present procedures for determining employee noise exposure will be presented.