Safety Tidbit 7.04 - Significant Threshold Shifts

 

Safety Tidbit 7.04 – Significant Threshold Shifts

 

Reference: 29 CFR 1904.10: Recording and Reporting Occupational Injuries and Illnesses

Centers for Disease Control and Prevention. (2018, February 5). Controls for noise exposure. Centers for Disease Control and Prevention. Retrieved from https://www.cdc.gov/niosh/topics/noisecontrol/default.html. 

 

This Safety Tidbit was written by my student, Ms. Megan Rutledge – a senior in the Safety Sciences Program at the Indiana University of PA graduating Summer 2022.

 

          OSHA defines an STS as a change in hearing threshold, relative to the baseline audiogram for that specific employee, of 10 dB or more at 2000, 3000, or 4000 Hz in one or both ears. The audiologist compares the current and baseline audiograms; if the employee never had a recordable hearing loss. However, if the employee has experienced a recordable hearing loss, the current audiogram will be compared to the revised baseline audiogram from when the hearing loss occurred. If retested in 30 days, the employer need not record the first audiogram.  

           There are no special rules on determining whether the hearing loss was work-related or not unless a physician or health care provider determines the hearing loss is not work-related. The health care provider must follow the rules set out by 29 CFR 1904.5 when determining if the hearing loss is work-related. Age may also be a factor of a recordable hearing loss or an STS. 

The current audiogram results may be adjusted for age using Tables F-1 or F-2 in appendix F of 29 CFR 1910.95.

           Employers can protect their employees by providing appropriate safeguards to reduce noise levels. Listed below are some tips to follow to protect your workers from potentially having a Significant Threshold Shift:

1. Select low-noise tools and machinery, if possible.
2. Lubricate gears routinely.
3. Place a barrier between the employee and the source of the noise.
4. Provide adequate hearing protection- ear muffs or earplugs, whichever the employee uses.
5. Isolate the noise source in an enclosure or insulated room.

 

Hope this was helpful and thank you for reading my Safety Tidbits! Comments and questions are always welcome. ~ Bryan

 

P.S. If you have a new safety or health question, please let me know.