The 2003 Occupational Safety and Health Administration (OSHA) Occupational Injury and Illness Recording and Reporting Final Rule changed the definition of recordable work-related hearing loss. We performed a study of the Alcoa Inc. audiometric database to evaluate the impact of this new rule. The 2003 rule increased the rate of potentially recordable hearing loss events from 0.2% to 1.6% per year. A total of 68.6% of potentially recordable cases had American Academy of Audiology/American Medical Association (AAO/AMA) hearing impairment at the time of recordability. On average, recordable loss occurred after onset of impairment, whereas the non-age-corrected 10-dB standard threshold shift (STS) usually preceded impairment. The OSHA Final Rule will significantly increase recordable cases of occupational hearing loss. The new case definition is usually accompanied by AAO/AMA hearing impairment. Other, more sensitive metrics should therefore be used for early detection and prevention of hearing loss.
Noise-induced hearing loss is one of the most prevalent occupational conditions. 1 Since the 1983 Occupational Safety and Health Administration (OSHA) Hearing Conservation Amendment, annual audiometric surveillance of individuals exposed to noise at levels of 85 dBA or greater has been a central part of industrial hearing-conservation programs. The 1983 OSHA rule defines a 10-dB “shift” or worsening in hearing at an average of 2000-, 3000-, and 4000-Hz frequencies as a Standard Threshold Shifts (STS). The 1983 standard allows age-correction of an STS for presbycusis using standardized tables, but makes it clear that such age correction is optional. If the professional supervisor of the hearing-conservation program (a physician or audiologist) determines an STS to be work-related, the OSHA standard mandates action including retesting, written notification, and counseling regarding hearing protection.
The 1983 OSHA standard, however, does not specify which hearing loss cases need to be recorded on a company’s OSHA log. Later guidance documents required the recording of hearing loss cases if there had been an average shift in hearing from a baseline of 25 dB or more at the frequencies of 2000, 3000, and 4000 Hz, again allowing age correction.
In January 2001, OSHA released a draft of a new recordkeeping standard. This standard originally proposed the recording of all work-related 10-dB STSs (age correction allowed) on the OSHA 300 log. This draft received support from a number of professional groups, including the American College of Occupational and Environmental Medicine, the American Academy of Audiology (AAO), the Council on Accreditation of Occupational Hearing Conservation, and National Hearing Conservation Association. At the same time, OSHA received comments that recording of 10-dB STSs would result in many “false-positive recordings” either because of “audiometric testing errors, because the hearing loss was temporary and not persistent, or because the case was insufficiently work-related.” Commenters taking this position challenged the medical significance of a 10-dB STS, stating that the OSHA recordability provisions are intended to “collect data on serious injuries and illnesses, not potential precursors.”2
In 2002, OSHA released a revised recordkeeping rule, requiring the recording of work-related 10-dB STS on the OSHA 300 log only if the absolute average at 2000, 3000, and 4000 Hz was equal to or greater than 25 dB. This rule took effect on January 1, 2003. In the decision to add the requirement that cases of 10-dB STS should also exhibit at least 25 dB of hearing loss in the average of 2000, 3000, and 4000 Hz, OSHA stated that the 10-dB STS at higher levels (above 25 dB) are “more significant,” and that the new rule provides a reasonable “middle ground” solution to “reconcile the differences between a highly sensitive measure (all 10-dB shifts) and increasingly insensitive measures (15-, 20-, or 25-dB shifts).”
In an analysis of the impact of the new rule, OSHA reviewed a National Institute for Occupational Safety and Health (NIOSH) database of audiograms to determine the proportion of audiograms meeting the recording criteria. This database was assembled in 1987 and includes audiometric data on noise-exposed employees from representative companies in the United States and Canada. A total of 3.09% of audiograms met the final rule’s criteria for recording hearing loss, whereas 0.83% met the previous recording criteria of a 25-dB shift. Based on national projections of 4,680,500 workers enrolled in hearing-conservation programs, OSHA calculated the new rule would lead to an additional 105,000 cases of occupational hearing loss being recorded annually.
We performed an analysis of a large industrial audiometric database to provide an independent review of the significance and impact of the changes in the OSHA hearing loss recordkeeping rule.