OSHA recently posted one of the most interesting LOI’s I have seen in quite a while. Somone asked: If an employee exposure after de-rating falls below 85 dBA, would that be a justification to not record an STS shift on the OSHA 300 Log? Of course OSHA said NO, but it was a nice try. Here is OSHA’s full answer…
Question 1: If an employee exposure after de-rating falls below 85 dBA, would that be a justification to not record an STS shift on the OSHA 300 Log?
Response: First, OSHA does allow the worker’s use of hearing protection to be considered by an employer when making determinations of work relatedness. However, this should not be the sole criterion in such determinations, nor should the determination be reduced to an equation. Under OSHA’s recordkeeping regulation, an employer must consider many factors when determining whether hearing loss is work-related, and such determinations must be made on a case-by-case basis.
On July 2, 2002, OSHA issued a final rule which revised the criteria for recording work-related hearing loss cases. See, 67 Fed. Reg. 44037. As noted above, Section 1904.10(a) provides that if an employee’s audiogram reveals that the employee has experienced a work-related STS in hearing in one or both ears, and the employee’s total hearing level is 25 dBA or more above audiometric zero (averaged at 2000, 3000, and 4000 Hz) in the same ear(s) as the STS, the case must be recorded on the OSHA 300 Log. Section 1904.10(b)(5) requires an employer to consider a case to be work-related only when exposure at work either caused or contributed to the hearing loss, or significantly aggravated a pre-existing hearing loss. The Section goes on to state that there are no special rules in the recordkeeping regulation for determining whether an employee’s hearing loss is work-related, but that employers must use the same rules contained in Section 1904.5 when making determinations for any and all employee injury/illness cases, including hearing loss cases. Among other things, Section 1904.5(a) provides that an employer must record a case if an event or exposure in the work environment is a discernable cause of the injury or illness. Please know that the work event need only be one of the discernable cause, it need not be the sole or predominant cause. See, the preamble to OSHA’s January 19, 2001, final rule revising the recordkeeping regulation, 66 Fed. Reg. 6943.
In the preamble to the July 2, 2002, final rule, OSHA explained that “[W]hen evaluating the work relatedness of a given hearing loss case, the employer should take several factors into account.” These factors include the worker’s prior occupational and non-occupational noise exposure, evaluation of calibration records and the audiometric environment, investigation of related activities and personal medical conditions, and age correction. Another “important factor to consider is the effectiveness of the hearing protection program. When employees are exposed to high levels of noise in the workplace, and do not wear appropriate hearing protection devices, a case of hearing loss is more likely to be work-related. If an employee’s hearing protection devices are not appropriate for the noise conditions, if they do not fit properly, or if they are not used properly and consistently, they may not provide enough protection to prevent workplace noise from contributing to a hearing loss case.” See, 67 Fed. Reg. 44045.
Thus, a determination of work relatedness should include an assessment of the appropriateness of the employee’s hearing protection worn. However, while your application of the de-rating method to the NRR of the hearing protection device is a conservative assessment of workplace conditions, you should know that when OSHA assesses the adequacy of a hearing protection device to determine an employer’s compliance with the hearing conservation requirements of Section 1910.95, we only subtract 7 dB from the NRR. The additional safety factor of 50 percent is only applied by OSHA when considering whether the employer should be implementing engineering controls. [OSHA Instruction TED 01-00-015]
Finally, besides assessing the level of protection of the worker’s hearing protector, your determination should also consider whether the given worker actually used the protection, and whether the worker was properly trained in wearing the protection. These, along with all the other criteria in Section 1904.10, should be included in your determination of the work relatedness of a hearing loss case.
Additional guidance for hearing professionals on determining when hearing loss is work-related is available from the Council for Accreditation in Occupational Hearing Conservation (CAOHC), and from the National Hearing Conservation Association (NHCA).
Question 2: Instead of using 85 dBA as the criterion for evaluating the appropriateness of a de-rated hearing protector, should 82 dBA be used? Most hearing professionals consider 80 dBA as the minimum “safe” level, so what would OSHA consider as the minimum “safe” level to target?
Response: OSHA’s criterion is provided in mandatory Appendix B to §1910.95: “For employees who have experienced a significant threshold shift, hearing protector attenuation must be sufficient to reduce employee exposure to a TWA of 85 dB.” Any revision to the criterion in this Appendix would require notice and comment rulemaking. At present, OSHA has no plans to revise Appendix B to § 1910.95.
CLICK HERE for the LOI