Combating Noise in the Workplace

March 1, 2009

Article provided on behalf of the American Industrial Hygiene Association ( by Mary Ann Latko, AIHA director of Scientific and Technical Initiatives.

For millions of American workers, exposure to dangerous noise levels is a daily fact of life, and occupational hearing loss is particularly insidious because it sneaks up on the worker. Like many construction workers, sheetmetal workers may not hear as well as they once did, and by retirement many sheetmetal workers have noticeable hearing loss.

Employers and employees alike need to take steps to protect workers’ hearing.

Because metal workers often are exposed to too much noise, a program for hearing-loss prevention should be put in place that includes noise monitoring, training, efforts to reduce noise and use of hearing protectors.

Noise-Exposure Level for Metal Workers

The legal noise exposure limit for construction workers in most states is an 8-hr. (full-shift) average exposure of 85-90 dB, a standard enforced by OSHA. Rick Neitzel, a certified industrial hygienist and research scientist at the University of Washington’s School of Public Health and Community Medicine, has been measuring noise exposures of construction workers. Among sheetmetal workers he found:

• The average level is 79 dB across a full work shift (noise below 85 dB is considered low hazard).

• About one-tenth of work shifts were above the 8-hr. limit of 85 dB (85-95 dB are harmful after long-term exposure and considered a caution zone).

• About one-fifth of work shifts had short periods of extremely high levels of noise above 115 decibels (short-term exposure of 95 dB and above is potentially harmful and considered a high hazard).

May Seminar on Pressroom Safety
The Precision Metalforming Association will hold its Pressroom Safety Seminar on May 27 at PMA headquarters in Independence, OH. Industrial-safety experts will teach attendees how to identify and eliminate hazards, evaluate and reduce risks, implement various means of protection and prevention, and decrease lost work days. For more information, contact PMA’s Deanna Nwosu at 216/901-8800 ext. 162 or

Measuring the noise level of various tools showed that:

• Noise levels of most tools used by sheetmetal workers exceed 85 dB;

• The highest average noise levels came from hammers, sledges, crew guns and drills;

• Noise levels were usually above 85 dB even when no tool was used.

Looking at whether sheetmetal workers use hearing protectors when their noise levels were above 85 dB, hearing

• Needed most when large power tools and rotohammers were used;

• Worn most often when workers used large power tools, welding and cutting equipment, and hand power saws;

• Almost never worn during use of rotary and squaring shears.

(To learn more about this research, visit

Working Together on Prevention

Sheetmetal workers and employers can work together to reduce exposure to hazardous noise via a number of methods: using quieter equipment, blocking noise with shields and moving noisy equipment a from workers.

Although some of these methods may be difficult to implement due to worksite location or equipment, another method can be employed by metal-industry workers themselves. Workers need to wear personal hearing-protection devices (HPDs), and business owners can help by providing hearing-loss training and HPDs to workers regardless of noise levels on the worksite. An environment can be considered noisy if workers must raise their voices to be heard by someone 3 to 5 ft. a—an arm’s length. If an employee notices a ringing sensation or dull, flat sound after leaving the worksite, that is an indication of a hazardous noise environment, and the worker should be wearing an HPD on the job.

Most sheetmetal workers will be protected if they wear a hearing protector with a noise-reduction rating (NRR) of 12 dB. For most activities, an NRR higher than 12 dB will block too much sound and may interfere with communication, including warning signals. Sheetmetal workers with high noise exposures need an NRR between 12 and 33 dB.

With many types of HPDs available, the best protector is one worn consistently and correctly for noise levels above 85 dB. Workers should remember to clean their hands when they insert earplugs to prevent chemicals, dirt and other irritants from entering the ear canal. An HPD must be comfortable to ensure that the worker is more likely to wear it, and employers should provide a variety of HPDs in different styles so that workers can find one that fits comfortably.

Encouraging metal-industry workers to care requires regular, consistent and repeated messages about the danger of noise and the nature of hearing loss. Communication is essential.

American Industrial Hygiene Association:

Industry-Related Terms: Insert
View Glossary of Metalforming Terms


See also: American Industrial Hygiene Assoc.

Technologies: Safety


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