# Occupational noise

(Redirected from Industrial noise)

Occupational noise is the amount of acoustic energy received by an employee's auditory system when they are working in the industry. Occupational noise, or industrial noise, is often a term used in occupational safety and health, as sustained exposure can cause permanent hearing damage. Occupational noise is considered an occupational hazard traditionally linked to loud industries such as ship-building, mining, railroad work, welding, and construction, but can be present in any workplace where hazardous noise is present.

## Regulation

In the US, the National Institute for Occupational Safety and Health (NIOSH) and the Occupational Safety and Health Administration (OSHA) work together to provide standards and regulations for noise in the workplace.[1]

National Institute for Occupational Safety and Health (NIOSH), Occupational Safety and Health Administration (OSHA), Mine Safety and Health Administration (MSHA), Federal Railroad Administration (FRA) have all set standards on hazardous occupational noise in their respective industries. Each industry is different, as workers' tasks and equipment differ, but most regulations agree that noise becomes hazardous when it exceeds 85 decibels, for an 8-hour time exposure (typical work shift). This relationship between allotted noise level and exposure time is known as an exposure action value (EAV) or permissible exposure limit (PEL). The EAV or PEL can be seen as equations which manipulate the allotted exposure time according to the intensity of the industrial noise. This equation works as an inverse, exponential, relationship. As the industrial noise intensity increases, the allotted exposure time, to still remain safe, decreases. Thus, a worker exposed to a noise level of 100 decibels for 15 minutes would be at the same risk level as a worker exposed to 85 decibels for 8 hours.[2] Using this mathematical relationship, an employer can calculate whether or not their employees are being overexposed to noise. When it is suspected that an employee will reach or exceed the PEL, a monitoring program for that employee should be implemented by the employer.[3]

The above calculations of PEL and EAV are based on measurements taken to determine the intensity of that particular industrial noise. A-weighted measurements are commonly used to determine noise levels that can cause harm to the human ear. There are also special exposure meters available that integrate noise over a period of time to give an Leq value (equivalent sound pressure level), defined by standards.

### Regulations in different countries

Permissible noise levels in different countries[4]
Country TWA, dBA

(for an 8-hour shift)

Level increase corresponding to doubling the dose

(Exchange rate)

Argentina 90 3
Australia 85 3
Brazil 85 5
Chile 85 5
China 70-90 3
European Union countries 85 3
Finland 85 3
France 85 3
Germany 85, 70, 55[6] 3
Hungary 85 3
India 90
Israel 85 5
Italy 85 3
Netherlands 80 3
New Zealand 85 3
Norway 85, 55, 70 3
RF[7] 80 3
Spain 85 3
Sweden 85 3
United Kingdom 85 3
USA 90 (100[8])* 5
Uruguay 90 3
* OSHA issued a directive to inspectors in 1983.[9] They are ordered to stop requiring employers to install engineering noise control if noise dose < 100 dBA. This decision is considered illegal,[10] but it is carried out in practice in most US states.[11]

These numerical values do not fully reflect the real situation. For example, the OSHA standard[3] sets the Action Level 85 dBA, and the PEL 90 dBA. But in practice, the Compliance Safety and Health Officer must record the excess of these values with a margin, in order to take into account the potential measurement error. And, instead of PEL 90 dBA, it turns out 92 dBA, and instead of AL 85 dBA, it's 87 dBA.[12]

## Risks of occupational hearing loss

Occupational noise, if experienced repeatedly, at high intensity, for an extended period of time, can cause noise-induced hearing loss (NIHL)[14] which is then classified as occupational hearing loss. Most often, this is a type of sensorineural hearing loss.[15]

Noise, in the context of industrial noise, is hazardous to a person's hearing because of its loud intensity through repeated long-term exposure. In order for noise to cause hearing impairment for the worker, the noise has to be close enough, loud enough, and sustained long enough to damage the hair cells in the auditory system. These factors have been taken into account by the governing occupational health and safety organization to determine the unsafe noise exposure levels and durations for their respective industries.

Noise can also affect the safety of the employee and others. Noise can be a causal factor in work accidents as it may mask hazards and warning signals and impede concentration. High intensity noise interferes with vital workplace communication which increases the chance of accidents and decreases productivity.[16]

Noise may also act synergistically with other hazards to increase the risk of harm to workers. In particular, toxic materials (e.g., some solvents, metals, asphyxiants and pesticides) have some ototoxic properties that may affect hearing function.

Modern thinking in occupational safety and health further identifies noise as hazardous to workers' safety and health. This hazard is experienced in various places of employment and through a variety of sources.

## Reduction

There are several ways to limit exposure to hazardous occupational noise. The hierarchy of controls[17] is a guideline for reducing hazardous noise. Before starting a noise reduction program, base noise levels should first be recorded.[18] After this the company can start to eliminate the noise source. If the noise source cannot be eliminated, the company must try to reduce the noise with alternative methods. This process is called acoustic quieting.

Acoustic quieting is the process of making machinery quieter by damping vibrations to prevent them from reaching the observer. The company can isolate the certain piece of machinery by placing materials on the machine or in between the machine and the worker to decreases the signal intensity that reaches the worker's ear.

If elimination and substitution are not sufficient in reducing the noise exposure, engineering controls should be put in place by the employer.[19][20][21][22][23][24][25][26][27][28][29][30][31][32] An engineering control usually changes the physical environment of a workplace. For noise reduction, an engineering control might be as simple as putting barriers in-between the noise source and the employee in order to disrupt the transmission path. An engineering control might also involve changing the machine that produces the noise. Ideally, most machines should be made with noise reduction in mind, but this doesn't always happen. Changing the machinery involved in an industrial process may not be possible, but is a good way to reduce the noise at its source.[33]

To decrease an employee's exposure to hazardous noise, the company can also take administrative control by limiting the employee's exposure time. This can be done by changing work shifts and switching employees out from the noise exposure area. An employer might also implement a training program so that employees can learn about the hazards of occupational noise. Other administrative controls might include restricting access to noisy areas as well as placing warning signs around those same areas.

If all other controls fail to decrease the occupational noise exposure to an acceptable level, hearing protection should be used.[34] There are several types of earplugs that can be used to attenuate the noise to a safe level. Some earplug types include: single-use earplugs, multiple-use ear plugs, and banded ear plugs.[35] Depending on the type of work being done and the needs of the employees, earmuffs might also be a good option. While earmuffs might not have as high of a noise reduction rating (NNR) as earplugs, they can be useful if the noise exposure isn't very high, or if an employee cannot wear earplugs. Unfortunately, the ability of HPDs decrease the risk of health damage is close to zero in practice.[9][36]

## Initiatives

Since the hazards of occupational noise exposure were realized, programs and initiatives such as the US Buy Quiet program have been set up to regulate or discourage noise exposure. The Buy Quiet initiative promotes the purchase of quieter tools and equipment and encourages manufacturers to design quieter machines.[37] Additionally, the Safe-In-Sound Award was created to recognize successes in hearing loss prevention programs or initiatives.[38]

General:

## References

1. ^ "Occupational Noise Exposure: Standards". Occupational Safety and Health Administration. Retrieved 2016-07-14.
2. ^ "Reducing Noise Exposure: Guidance & Regulations". www.cdc.gov. 2021-11-08. Retrieved 2022-04-05.
3. ^ a b US Occupational Safety and Health Administration (1983). "29 CFR 1910.95 Occupational noise exposure". www.osha.gov. Washington, DC: OSHA. Retrieved 18 July 2023.
4. ^ Suter, Alice H. (2011-05-24). "Noise. Standards and Regulations". Encyclopaedia of Occupational Health & Safety (Part VI. General Hazards) (4 ed.). International Labour Organization. Retrieved 14 July 2023.
5. ^ "Occupational Health and Safety Code". www.alberta.ca. Edmonton: Government of Alberta. 2023. Retrieved 14 July 2023.
6. ^ For mental work
7. ^
8. ^ Bruce, Robert D.; Wood, Eric W. (2003-05-01). "The USA needs a new national policy for occupational noise". Noise Control Engineering Journal. Reston, VA: Institute of Noise Control Engineering. 51 (3): 162-165(4). doi:10.3397/1.2839711. ISSN 2168-8710. Retrieved 29 July 2023. Quote: Over the past 30 years, there has been a wide range of regulatory action—varying from strict interpretation of the regulation in the early 1970s to a lackadaisical approach today, where an employer willing to hand out ear plugs may get away without a citation unless the time-weighted average level exceeds 100 dB on the A-weighted scale!
9. ^ a b Suter, Alice (2012). "Engineering Controls for Occupational Noise Exposure - The Best Way to Save Hearing" (PDF). Sound & Vibration. Henderson, Nevada: Tech Science Press. 48 (1): 24–31. ISSN 1541-0161. Retrieved 7 June 2023.
10. ^ Occupational Safety and Health Administration (2010-10-19). "Interpretation of OSHA's Provisions for Feasible Administrative or Engineering Controls of Occupational Noise". Federal Register. Proposed Rule. Washington, DC: Office of the Federal Register. 44 (201): 64216–64221. ISSN 0097-6326. Retrieved 29 July 2023. p. 64218: ... the majority's adoption of a cost-benefit test amounted to an unauthorized amendment of the standard. Commissioner Cleary’s view
11. ^ OSHA (July 6, 2022). "Appendix H. Economic Feasiblity Analysis of Noise Engineering Controls". OSHA Technical Manual (OTM) Section III: Chapter 5. Noise. US Occupational Safety and Health Administration. Retrieved 18 January 2023. `{{cite book}}`: `|website=` ignored (help)
12. ^ B.9 Extended Workshifts OSHA (July 6, 2022). "OSHA Technical Manual (OTM) Section III: Chapter 5. Noise". www.osha.gov. US Occupational Safety and Health Administration. Retrieved 18 January 2023. Instrument accuracy must be taken into account ... . Type-2 dosimeters are considered to have an error of ±2 dBA, and the Action Level must be corrected, accordingly. For example, for an 8-hour shift, the corrected Action Level would be 87 dBA ...
13. ^ Izmerov, Nikolai; Suvorov, Herman; Prokopenko, Ludmila (2001). "Chapter 4. Occupational hearing loss". The man and the noise (Человек и шум) (in Russian). Moscow: ГЕОТАР-МЕД. p. 103. ISBN 5-9231-0057-6.
14. ^ Technical Committee ISO/TC 43 Acoustics (2013). ISO 1999:2013 Acoustics — Estimation of noise-induced hearing loss (3 ed.). Geneva, Switzerland: International Organization for Standardization. p. 23. Retrieved 14 July 2023.`{{cite book}}`: CS1 maint: numeric names: authors list (link)
15. ^ Isaacson, Jon; Vora, Neil M. (2003-09-15). "Differential Diagnosis and Treatment of Hearing Loss". American Family Physician. 68 (6): 1125–1132. ISSN 0002-838X. PMID 14524400.
16. ^ "Effects of Noise on The Individual in the Workplace". soundcontroltech.com. Retrieved 2017-05-21.
17. ^ "CDC - Hierarchy of Controls - NIOSH Workplace Safety and Health Topic". www.cdc.gov. Retrieved 2018-02-23.
18. ^ Bies, David; Hansen, Colin; Howard, Carl (2017). Engineering Noise Control. Boca Raton: CRC Press. p. 248. ISBN 9781351228152.
19. ^ OSHA (July 6, 2022). "L. Noise Exposure Controls - Overview". OSHA Technical Manual (OTM) Section III: Chapter 5. Noise. US Occupational Safety and Health Administration. Retrieved 28 July 2023. `{{cite book}}`: `|website=` ignored (help)
20. ^ Driscoll, Dennis P. (2022). "Chapter 10: Noise Control Engineering". In D.K. Meinke, E.H. Berger, R.L. Neitzel, D.P. Driscoll & K. Bright (ed.). The Noise Manual (6th ed.). Falls Church, VA: American Industrial Hygiene Association. pp. 201–254. Retrieved 29 July 2023.`{{cite book}}`: CS1 maint: multiple names: editors list (link)
21. ^ Jensen, Paul; Jokel, Charles R.; Miller, Laymon N. (December 1978). Industrial Noise Control Manual. DHHS (NIOSH) Publication No 79-117 (Revised ed.). National Institute for Occupational Safety and Health. p. 380. Retrieved 29 July 2023.
22. ^ Cheremisinoff, Nicholas P. (31 December 1996). Noise Control in Industry. A Practical Guide. Elsevier. p. 203. ISBN 978-0-8155-1399-5. Retrieved 29 July 2023.
23. ^ Occupational Safety and Health Administration (1980). "Noise Control-A Guide for Workers and Employers". www.nonoise.org. U.S. Department of Labor. Retrieved 29 July 2023.
24. ^ Technical Committee, ISO/TC 43/SC 1 Noise (1995). "ISO/TR 11688-1:1995 Acoustics — Recommended practice for the design of low-noise machinery and equipment — Part 1: Planning". iso.org. Geneva, Switzerland: ISO. p. 25. Retrieved 29 July 2023.`{{cite web}}`: CS1 maint: numeric names: authors list (link)
25. ^ Technical Committee, ISO/TC 43/SC 1 Noise (2008). "ISO/TR 11688-2:1998 Acoustics — Recommended practice for the design of low-noise machinery and equipment — Part 2: Introduction to the physics of low-noise design". iso.org. Geneva, Switzerland: ISO. p. 46. Retrieved 29 July 2023.`{{cite web}}`: CS1 maint: numeric names: authors list (link)
26. ^ Technical Committee, ISO/TC 43/SC 1 Noise (2001). "ISO 15664:2001. Noise control design procedures for open plant". iso.org. Geneva, Switzerland: ISO. p. 24. Retrieved 29 July 2023.`{{cite web}}`: CS1 maint: numeric names: authors list (link)
27. ^ Technical Committee, ISO/TC 43/SC 1 Noise (2004). "ISO 17624:2004. Guidelines for noise control in offices and workrooms by means of acoustical screens". iso.org. Geneva, Switzerland: ISO. p. 14. Retrieved 29 July 2023.`{{cite web}}`: CS1 maint: numeric names: authors list (link)
28. ^ Technical Committee, ISO/TC 43/SC 1 Noise (2000). "ISO 15667:2000 Acoustics — Guidelines for noise control by enclosures and cabins". iso.org. Geneva, Switzerland: ISO. p. 50. Retrieved 29 July 2023.`{{cite web}}`: CS1 maint: numeric names: authors list (link)
29. ^ Technical Committee, ISO/TC 43/SC 1 Noise (2020). "ISO 11690-1:2020. Recommended practice for the design of low-noise workplaces containing machinery. Part 1: Noise control strategies". iso.org. Geneva, Switzerland: ISO. p. 29. Retrieved 29 July 2023.`{{cite web}}`: CS1 maint: numeric names: authors list (link)
30. ^ Technical Committee, ISO/TC 43/SC 1 Noise (2020). "ISO 11690-2:2020. Recommended practice for the design of low-noise workplaces containing machinery. Part 2: Noise control measures". iso.org. Geneva, Switzerland: ISO. p. 31. Retrieved 29 July 2023.`{{cite web}}`: CS1 maint: numeric names: authors list (link)
31. ^ Technical Committee, ISO/TC 43/SC 1 Noise (1997). "ISO/TR 11690-3:1997. Recommended practice for the design of low-noise workplaces containing machinery. Part 3: Sound propagation and noise noise prediction in workrooms". iso.org. Geneva, Switzerland: ISO. p. 24. Retrieved 29 July 2023.`{{cite web}}`: CS1 maint: numeric names: authors list (link)
32. ^ Technical Committee, ISO/TC 43/SC 1 Noise (1998). "ISO 14163:1998. Guidelines for noise control by silencers". iso.org. Geneva, Switzerland: ISO. p. 44. Retrieved 29 July 2023.`{{cite web}}`: CS1 maint: numeric names: authors list (link)
33. ^ "Reducing Noise Exposure: Noise Controls". www.cdc.gov. 2021-11-08. Retrieved 2022-04-05.
34. ^ "1910.95(b)(1) | Occupational Safety and Health Administration". www.osha.gov. Retrieved 2022-04-04.
35. ^ Sokol, Bill (March 1, 2005). "Ear Plugs: A Field Guide". Occupational Health & Safety (Waco, Tex.). 74 (3): 46, 48–50, 52. PMID 15846964. Retrieved 2022-04-04.
36. ^ Groenewold M.R.; Masterson E.A.; Themann C.L.; Davis R.R. (2014). "Do hearing protectors protect hearing?". American Journal of Industrial Medicine. Wiley Periodicals. 57 (9): 1001–1010. doi:10.1002/ajim.22323. ISSN 1097-0274. PMC 4671486. PMID 24700499. Retrieved 29 July 2022.
37. ^ "Buy Quiet". Centers for Disease Control and Prevention. 25 October 2021.
38. ^ "Safe-in-Sound:Excellence in Hearing Loss Prevention Award". Safe-in-Sound. Retrieved 2016-07-14.