COMPARISON OF DAILY NOISE EXPOSURES IN ONE WORKPLACE BASED ON NOISE CRITERIA RECOMMENDED BY ACGIH AND OSHA

The objective of this study was to determine the impact of the new Ame rican Conference of Governmental industrial Hygienists (ACGIH(new)) no ise criteria, as compared to the current U.S. Occupational Safety and Health Administration (OSHA) hearing conservation criteria, on the num ber of employees to be included in the hearing conservation program at one industrial facility. This study also compares the combined effect s of a 3-dB versus a 5-dB exchange rate and an 80-dBA versus a 90-dBA measurement threshold on daily noise doses and equivalent 8-hr time-we ighted averages (TWAs). Employee noise exposures were measured using p aired Ametek MK-3 noise dosimeters, one dosimeter set to the ACGIH(new ) noise criteria and one to the present OSHA hearing conservation crit eria. Samples were collected over 4-hr periods (half-shifts) for 50 em ployees in 7 job categories. Results indicate that the majority of the employees' exposures fell below an 8-hr TWA(OSHA) of 85 dBA. The diff erences between the predicted TWA(ACGIHnew) and the TWA(OSHA) ranged b etween 0.2 and 12.6 dB for paired samples, with an average difference of 4.6 dB. Overall, these differences in employee 8-hr TWAs would proj ect a 36% increase in the percent of the population enrolled in the he aring conservation program and a 50% increase in the percent of the po pulation required to wear hearing protection.