The legal limitation on noise exposure in work environments is 90 decibels using A-weighted sound levels, or 90 dBA, during an 8-hour day, reports the Occupational Safety and Health Administration of the U.S. Department of Labor. For every 5 dBA of noise above the limit, workers must cut their time of exposure to the noise by half. The OSHA recommended noise exposure limitation is 85 dBA in 8 hours, with every increase of 3 dBA reducing exposure time by half.
Exposure to workplace noise above legal maximum levels can cause permanent loss of hearing as well as psychological and physical stress, warns OSHA. Indications that work environments are too noisy include having to shout at co-workers an arm’s length away or lingering ringing, humming or hearing loss when leaving work. OSHA requires employers in service and manufacturing sectors of general industry to assess noise levels and provide free hearing protection and yearly hearing exams for their employees.
Recommended steps to reduce noise levels in work environments include maintaining and lubricating equipment, choosing low-noise machinery and tools, and isolating the noise with barriers, according to OSHA. Employers can also limit employees’ exposure time to high noise levels, distance employees from loud machinery, and provide soundproof rooms where employees can recover. Although hearing protection devices are sometimes necessary, they are less desirable than other measures.