Noise Exposure and Evaluation at Tire- Changing Facilities.

Thirty (30) personal noise-exposure samples were collected on 20 tire-changing and repair technicians in three tire-changing facilities to determine their personal noise exposures and to estimate the maximum number of tire changes that could be performed without exceeding occupational exposure limits. Of the 30 projected 8-h time-weighted average noise samples, none exceeded the Occupational Safety and Health Administration's Permissible Exposure Limit, 1 (3%) exceeded the Occupational Safety and Health Administration's Action Level, and 18 (60%) exceeded the American Conference for Governmental Industrial Hygienists Threshold limit Value of 85 dBA, indicating the need for a hearing loss prevention program. The average shift time for the technicians was 6 h and 42 min and the average number of tire changes was 18. Based on the projected 8-h noise exposure 95% upper confidence limits, the estimated maximum number of tires that could be changed without exceeding the Occupational Safety and Health Administration's noise action level was 32 tires, the permissible exposure limit greater than 40 tires, and the American Conference of Industrial Hygienists' Threshold Limit Value was less than 20 tires. In addition, area noise samples of tire-changing equipment were taken with a sound-level meter to identify the noise sources that contributed to the tire technicians' exposures. The air ratchet, tire-changing machine, and tire-bead seater were measured at noise levels >85 dBA, increasing the risk of noise-induced hearing loss to the technicians.