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Keeping the Noise Down
Ear Plugs Are Not the Only Answer

HOW NOISE CAN HURT YOU

• Damage to hearing. Long-term exposure to high noise levels may cause severe hearing loss and can also cause "ringing" in the ears.
• Damage to the rest of the body. High noise levels may contribute to diseases caused by stress, such as ul­cers and heart disease. Many workers exposed to noise complain of head­aches, irritability, nervousness, and fatigue.

MEASURING NOISE

Noise is measured in units called deci­bels ("dBs") with a machine called a sound level meter.

A general rule of thumb when com­paring noise levels is that an increase of 3 decibels doubles the sound inten­sity and an increase of 10 decibels makes the sound 10 times more in­tense.

The sound level shows how strong or intense the sound is, which is not the same as how loud it sounds to you. A sound which is 93 decibels has twice the intensity of a sound at 90 decibels and can cause much more hearing loss‑‑even though it may not sound twice as loud to you.

OSHA RULES

OSHA rules say you cannot legally be exposed to more than 90 decibels averaged over an 8-hour shift.

The rules also say how long you can legally be exposed to noise levels above 90 dB.

For instance, you can be exposed to a constant noise level of 94 dB during 41 1/2 hours per day.

Table 1 shows the number of hours under the OSHA rules that workers can be exposed to certain levels of noise.

When workers are exposed to noise levels above the legal limits, OSHA rules say that employers must use engineering controls (changes in the work environment) or administrative controls (limits on worker's exposure time) in order to reduce the exposure.

Until these control measures are effective, workers must be provided with equipment to protect their hear­ing.

According to OSHA rules, employers must provide free ear protection to workers exposed to an average of 85 dB or more.

The OSHA rules also say that em­ployers must provide free hearing tests to workers exposed to 85 dB or more, averaged over an 8-hour shift.

New tests must then be taken at least once a year. The tests must be conducted by a trained person. The union has the right to see the results.

Employers are required by OSHA to give you a copy of these OSHA noise rules and to post one in the workplace.

TABLE 1

Amount of time workers may be exposed to

various noise levels

Noise level

in decibels:                90        92        95        100     105     110     115

Hours of

exposure allowed:   8         6         4           2          1        1/2       1/4

WAYS TO CONTROL NOISE

1. Engineering controls.

• Quieter equipment. Use nylon rollers instead of steel wheels with bearings. Consider noise specifications when purchasing new equipment. Add mufflers to re­duce motor noise.
• Enclose noisy machines.
• Enclose operators.
• Barriers. Place sound barriers be­tween noisy areas and the rest of the workplace. mill.
• Change processes. Examples: reduce machine speed or the distance that material falls.
• Insulation. Use sound absorbent material on walls and ceilings. Mount vibrating machinery on insulated cushions.
• Good maintenance. Lubricate machine parts regularly.

2. Personal protective equipment.

As a last resort‑‑when better methods don't work to reduce noise or while they are being put in place‑‑workers can be protected from hearing loss by the use of earplugs or muffs.

3. Administrative controls. Workers are sometimes moved to less noisy jobs for part of the workday to reduce their total noise exposure. 

Courtesy of TheWorkSite.org.