Page 20 - OHS, September 2024

NOISE MONITORING
Despite the irreversible nature of NIHL, over half of noise-exposed workers report not wearing hearing protection.
and shift durations can all be compared to the same action values. With the eight-hour averaged action levels, employers must measure representative samples of employees’ exposure to noise. To do this, an average measurement must be taken which is known as the LAVG, a logarithmic average. This is done with a hand- held sound level meter or a noise dosimeter which can be work throughout the day. In the case of the noise dosimeter, as it is worn
through the day it will display the eight-hour noise exposure.
If the workplace in which the sample is taken is continuously noisy—and will remain so over the workers’ shift—then the mea- surement can be taken over the course of a few minutes, as this is a representative average of the conditions throughout the day. If the noise level fluctuates throughout the day, longer samples must be taken to achieve a representative average when using devices such as a sound level meter. A noise dosimeter is a bodily worn device that can be worn to measure exposure during a working day, which is especially useful if the worker is mobile and therefore it becomes increasingly difficult to measure exposure using a handheld sound
level meter.
Controlling Noise
Any sound over 85 decibels(dB) can damage hearing, meaning the operation of concrete mixers, forklifts, jackhammers, nail guns and masonry drills all pose a permanent risk to worker health if effec- tive control measures are not put in place.
The hierarchy of controls should always be used with hearing protection being the last resort, or a first aid measure until noise can be controlled at the source. They are listed from the most to least effective and include elimination, substitution, engineering controls, administrative controls and personal protective equipment (PPE).
A noise survey can help employers determine which employees are at risk. For noise control and control of noise sources, a noise- control survey should be conducted to identify the source and de- termine its contribution to the area noise level and worker noise exposure so that businesses can identify at-risk employees and ensure they adhere to OSHA regulations. However, professionals who undertake the monitoring must be trained and prepared with the right equipment as minor errors in noise level estimates can lead to major errors in exposure calculations. This results in greater risks for employers and employees’ long-term ear health.
In 1981, OSHA implemented new requirements to protect all workers in general industry for employers to implement a Hear- ing Conservation Program where workers are exposed to a time- weighted average noise level of 85 dBA or higher over an eight-
hour work shift.
These programs require employers to evaluate noise levels regu-
larly, offer hearing protection that has been determined as adequate for the noise in the workplace and train employees on managing noise. This is unless equipment and schedules are made so that they are less noisy and worker exposure to noise is less than the 85 dBA.
Noise assessors should ideally use both a sound level meter, primarily designed as a hand-held device used by an operator, and a noise dosimeter, which a staff member wears for their working shift. This ensures primary noise sources can be identified and, when exposure is occurring, to establish a noise control program.
Wear Hearing Protection: A Last Resort
If noise levels are above safety regulations, workers must wear pro- tection. When selecting the right makes and models, the attenua- tion level is critical and noise levels at the ear must be reduced so that exposure is below 85dB(A) TWA. NIOSH has published three methods for calculating the attenuation of hearing protectors. However, making sure people wear the protector for the entirety of their shift is essential to ensure real-world protection.
Despite the irreversible nature of NIHL, over half of noise-ex- posed workers report not wearing hearing protection.3
Employers can take a proactive approach to encourage all-day wear by considering comfort, communication, the environment, the individual and the relationship with other PPE. Removing PPE, even for short periods, has a significant effect on exposure. There- fore, it is crucial that hearing protection is comfortable to increase worker acceptance and support the likelihood of all-day wear.
When working in an environment with airborne hazards pres- ent, for example, ensure the hearing protection that was provided is comfortable and unobtrusive to the respiratory protection worn.
Every worker on site will have unique physical characteristics that will affect how comfortable the chosen hearing protection is. Some will be more comfortable wearing ear defenders, others will be more suited to ear plugs. The more comfortable an individual is, the less likely they are to remove the PPE.
The interaction of hearing protection with other PPE is also a significant factor. For example, an employee wearing prescription or safety glasses will not obtain an adequate fit from a standard earmuff. So plugs or semi-inserts may be more suitable.
The world is getting louder, employers must act now to imple- ment a successful and effective noise control regime. However, skill and knowledge of measuring noise can take years to build, so this guidance is a starting point. If certain aspects of noise monitoring, protection and control are outside of an individual’s competencies then external consultancies, training and support should be sought to bridge knowledge gaps and ensure employees get the critical protection they need. When it comes to a permanent health issue like hearing loss, it’s never worth the risk.
Tim Turney is Global Marketing Manager at global monitoring equip- ment manufacturer Casella. Casella is dedicated to reducing occupational health and environmental risks and sup-
porting businesses in solving their moni-
18 Occupational Health & Safety | SEPTEMBER 2024
www.ohsonline.com
toring and analysis needs. For more infor- mation about Casella’s noise monitoring solutions visit, www.casellasolutions.com/ us/en.html.
REFERENCES
1. tinyurl.com/bdz3pepp 2. tinyurl.com/3v25bk3k 3. tinyurl.com/4mra9be