Page 42 - OHS, September 2022

HEARING PROTECTION
avoiding actions that can invalidate monitoring data. Having a high-level understanding of the instrument’s purpose drives acceptance. Despite your best communication efforts, there are just some employees who can’t help themselves (i.e., play with the unit like a video game console or hide it in unexpected places, such as in a microwave, or tell you that the noise dosimeter was making noises). These situations are best handled by talking to the employee and supervisor and trying to find a way to save the dosimetry data, if possible.
Use an SLM and a noise dosimeter together during a noise survey. Each instrument provides valuable, unique information. The combination results in more complete information that better pinpoints noise controls. It is best practice to obtain sound level measurements with an SLM frequently during noise dosimetry. An SLM will document noise at specific points in time and from sources in the area. Its values will validate dosimeter readings and provide insight into how and when exposure is occurring. Note that SLMs cannot be used as noise dosimeters, conversely, noise dosimeters cannot be used as SLMs; this is a common mistake made in noise surveys. They work together but not interchangeably.
Take detailed field notes during a survey. This will facilitate a better understanding of events during the work shift. Noise instruments will record exposures but it’s the OEHS professional’s observations that are crucial to providing context to the data and identifying concerns, noise sources and other information to better apply the industrial hygiene hierarchy of controls.7 Record readable observations. When it comes to litigation, not only are noise data and calibration documentation important but notes taken during the noise survey may also be used.
You Have Successful Noise Survey Data. Now What?
Evaluate collected data from dosimeters, SLMs and observations in light of the applicable regulations and guidelines. Identify which tasks have the highest noise exposures and exceed applicable regulations. Determine noise sources that are causing elevated exposure. Even for exposures that fall below regulations, it is good practice to determine if there are elevated noise sources that need addressed.
Create a report of findings that discusses elevated noise exposures and recommends controls. Engineering controls
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may include shields, barriers, acoustical enclosures and sound- absorbing materials. If these are not feasible, document the reasons and proceed to administrative controls and/or PPE. Examples of administrative controls include rotating employees and programming machines to operate at a certain length of time during shifts. PPE should not be the first option when mitigating exposures. If the only option, choose hearing protection devices with the appropriate noise reduction rate (NRR–located on the hearing protector package). The higher the NRR, the more protective. Consult the OSHA Technical Manual (OTM) Section III, Chapter 5, Appendix E to help determine the best NRR based on the noise data.8
Performing noise surveys can be challenging for OEHS professionals, particularly if performed infrequently. It is my hope that this article provides insight into some of the pitfalls of noise surveys and promotes consideration of the technical as well as the human aspects of a survey. With knowledge and the best monitoring tools, we can handle our nemesis noise and protect workers from hearing loss.
Lucinette Alvarado, CIH, has worked as an industrial hygienist for 15 years and currently serves on the AIHA Board of Directors. She is the corporate CIH and Technical Services Manager for SKC Inc.
REFERENCES
1. https://www.osha.gov/noise
2. https://www.cdc.gov/niosh/topics/ohl/default.html
3. https://www.tandfonline.com/doi/full/10.1080/15459620490476503
4. https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1 910.95AppG#:~:text=HOW%20IS%20NOISE%20MEASURED%3F,level%20 meter%20and%20the%20dosimeter.
5. https://webstore.ansi.org/Standards/IEC/iec61672ed200 2?gclid=CjwKCAjwquWVBhBrEiwAt1KmwovCKSJCE-BYQkW79_ jtdk9JULRVdo5BlMXn0xGJ1DBSn0p9qx19DBoCoIwQAvD_BwE
6. https://www.osha.gov/otm/section-3-health-hazards/chapter- 5#measurements
7. https://www.cdc.gov/niosh/topics/hierarchy/default.html
8. https://www.osha.gov/otm/section-3-health-hazards/chapter- 5#appendixe
38 Occupational Health & Safety | SEPTEMBER 2022
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