Handout for Sheet Metal Workers on sources of noise, effects of noise on hearing, and how to protect yourself from noise, including selection of hearing protection. Part of a collection. Click on the 'collection' button to access the other items.
Bricklayers, Cement Masons, Electricians, Insulation Workers, Ironworkers, Masonry Restoration Workers, Operating Engineers, Sheet Metal Workers, Tilesetters WISHA noise Web site
OSHA noise Web site
This study and these brochures are funded by
National Institute for Occupational Safety and Health
Washington state Medical Aid and Accident Funds
Photos: Sebrina Somers, Sue Swan; Illustrations: ©2004 www.clipart.com
Like many construction workers, you may not hear as well
as you once did, and that may worry you. Your concerns
are real—by retirement, many construction workers have
a noticeable hearing loss. You and your employer need to
take steps to protect your hearing, and this pamphlet will
help you do so.
What is noise?
Noise is unwanted sound. It is measured on a decibel scale. Noise levels for some familiar sounds are shown at left.
What if you are exposed to too much noise?
Noise exposures that are loud enough and last long enough can damage nerves in your inner ear. This causes permanent and irreversible hearing loss.
Hearing loss makes it hard to:
- talk with family, friends, and coworkers.
- hear warning signals
- enjoy music, nature, voices, and other good sounds.
Safe noise levels
The legal limit for construction workers in Washington is an 8-hour (full-shift) average noise exposure of 85 decibels. This limit is enforced by WISHA. Construction workers in most other states have an 8-hour limit of 90 decibels enforced by OSHA.
If you must raise your voice to talk to someone an arm’s length away, the noise level is probably over 85 decibels. Workers with an average noise exposure above 85 decibels need to wear hearing protectors—either earplugs or earmuffs — and be in a hearing loss prevention program. You should wear hearing protectors any time noise levels are over 85 decibels.
Noise exposure levels for sheet metal workers
University of Washington researchers have been measuring the noise exposures of construction workers. Among sheet metal workers, we found:
- the average level was 79 decibels across a full work shift
- about one-tenth of work shifts were above the 8-hour limit of 85 decibels
- about one-fi fth of work shifts had short periods of extremely high levels (above 115 decibels)
Potentially harmful after short-term exposure (95 decibelsand above)
Harmful after long-term exposure(85-95 decibels)
Noise below 85 decibels
Noise levels of tools
We measured the noise levels of various tools. We found that:
- most tools used by sheet metal workers exceeded 85 decibels
- the highest average noise levels came from hammers, sledges, screw guns, and drills
- noise levels were usually above 85 decibels even when no tool was used
Hearing protection use
We looked at whether sheet metal workers used hearing protectors when their noise levels were above the limit of 85 decibels. We found that hearing protection was:
- used two-thirds of the time it was needed overall
- needed most with large power tools and rotohammers
- worn most often with large power tools, welding and cutting equipment, and hand power saws
- almost never worn when needed with rotary and squaring shears
How you can stop hearing loss
Our research shows sheet metal workers are often exposed to too much noise, and need to be in a hearing loss prevention program. This program should include noise monitoring, training, efforts to reduce noise, and use of hearing protectors.
The basics of hearing protection
- Consider noise sources around you— not just your own tasks—when deciding when to wear hearing protectors.
- If your noise exposure is intermittent, try banded earplugs or earmuffs. They are easy to put on and take off.
- All hearing protectors are labeled with a Noise Reduction Rating (NRR) in decibels. The NRR is usually about twice as high as the protection you will actually get.
- Keep your protectors with you so you have them when you need them.
How much hearing protection do I need?
Based on our measurements, most sheet metal workers will get enough protection if they wear a hearing protector with an NRR of 12 decibels. For most activities, an NRR higher than 12 decibels will block too much sound and may interfere with communication, including warning signals. Sheet metal workers with very high noise exposures need an NRR between 12 and 33 decibels.
Finding a hearing protector that works for you
Hearing protectors are like shoes: one style will not work for all workers and all exposure levels. You may have to try several styles before you find one that is comfortable and works for you. It may take several weeks before you get used to wearing hearing protectors. Your employer should train you on how to wear hearing protectors properly.
Also keep in mind
Your employer may be able to reduce your exposure by using quieter equipment, blocking noise with shields, or moving noisy equipment away from you. All sheet metal workers should be enrolled in a hearing loss prevention program—find out if your employer has one.