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SOME LINKS OF INTEREST

NHCA

1998 State OSHA Citations for 1910.95

1998 Federal Citations for 1910.95

NOISE DOSIMETRY

On-Site Hearing Test and Training
29 CFR 1910.95

Hearing Conservation Program

You Decide!

The decision to conduct, or not to conduct, annual hearing test & too train your employees, is not necessarily regulatory based. The decision, must be also based on the potential cost associated with noise induced hearing loss.

When reviewing the estimated annual cost of loss of productivity, special education, and medical care due to hearing loss the cost is $56 billion, on an annual basis. The average disability for Occupational Noise Induced Hearing loss is $17,000.00 per ear.

To estimate the potential financial and regulatory impact of Noise Induced Hearing Loss at your facility you will need to consider the following information. (Workforce Demographics)

Review Your Workforce Demographics:

Our research indicates, the average age of the American industry worker is 37 years old, worked in industrial environments for over 12 years, and will be working until he/she reaches social security retirement age and beyond. This indicates that employers will have an experienced workforce, but a workforce that has been exposed to potential cumulative illnesses and injuries for a long period of time. As the workforce continues to age, the number of workers who experience hearing loss and the cost of workers compensation will increase.

What is the Average Age of Your Workforce?
10 Million people have hearing loss due to noise.

Who in your workforce uses firearms, chain saws, listen to loud music, and visits the racetrack?
50 Million Americans who own firearms are at risk for noise induced hearing loss.

Where have members of your workforce been employed?
The number of people with hearing loss in the US, are between 25 million and 28 million, or about 1 in 10.

Compare Your Workforce Demographics:

Researchers report a sharp increase in the number of younger people, in their 40ís and 50ís, who complain of not hearing well. While more than 30% of people over 65 have some type of hearing loss, 14% of those between 45 and 64 having hearing loss. Traditionally, statistics on hearing loss have shown seniors from 65 years of age to be the most vulnerable age group over 30 percent reporting hearing loss while approximately 10 percent in the 40 to 65 year age group acknowledge loses. Experts predict that as America ages, hearing loss will become epidemic. The last Census indicated that 13% of the population was over 65, and projections are that this figure will double over the next three decades as baby boomers enter their senior years. This means that one-quarter-more-of the population will be over 65. (How to Limit Your Cost Link: new page)

Do you conduct pre-employment screenings?
Only 16% of physicians routinely screen for hearing loss.

How does hearing loss potentially effect production?
Hearing Loss is the # 1 handicapping disorder.


How To Limit Costs Associated With Hearing Loss?

It is important to realize that all noise induced hearing loss can not be prevented. The basic fact that the American workforce is aging and that hearing loss is often associated with aging, it can be assumed an inevitable. However, there are some steps that can be taken, and in some cases are required by the OSHA, to prevent unnecessary hearing loss in the workplace, reduce cost, and meet regulatory requirements.

Educate employees about the potential for hearing loss, not just in the workplace but also in their everyday activities. Explain to employees the benefits of wearing hearing protection, how too properly wear hearing protection, when to wear hearing protection, the anatomy of the ear.*

Have a noise area survey conducted to determine the noise level. If the noise levels are above 85DBA conduct an 8-hour TWA sample. If the noise levels continue above 85 DBA then conduct an abatement feasibility study. If you can not abate the noise, provide hearing protection for your employees.*

Provide hearing screenings to compare the hearing ability of each employee on an annual basis. If an individualís screening indicates a hearing loss, refer the individual for medical referral.*

*Required by the OSHA.

The idea is to reduce potential cost, reduce liabilities, while meeting regulatory requirements. (Back to HCI Services)


Introduction

HEARING CONSERVATION

Compensation for noise-induced hearing loss is one of the most frequently compensated occupational injuries in the United States. Hundreds of thousands of workers apply for such compensation each year and the numbers are progressively increasing as the workforce ages and the judicial system becomes more sympathetic to their needs. Hearing Conservation Programs are designed to prevent excessive noise which can cause permanent hearing damage. These prevention methods may include both Engineering and/or Administrative controls when the worker is exposed to eight-hour, time weighted noise levels of 85 decibels (85 dB). The preferable method to prevent exposures is to eliminate the exposure by integrating engineering controls which abate or attenuate the noise exposure level to less than 85 dB. In those cases where engineering controls are not feasible, administrative controls are necessary.

Noise abatement can be accomplish in some cases by engineering controls and equipment maintenance or modification to reduce the intensity of the noise either at the source or in the immediate environment. Some examples of noise control suggested by the National Institute for Occupational Safety and Health include:

a. New or replacement equipment with lower noise levels.

b. Replacement of worn or unbalanced parts in existing equipment.

c. Maintenance of proper adjustment of equipment.

d. Security of covers or safety shields on machines.

e. Lubrication of moving parts on equipment.

f. Substitution of belt drives for gears.

g. Use of rubber or plastic linings for vibration dampening.

h. Use of sound-absorbing materials.

i. Installation or replacement of mufflers on internal combustion engines and compressors.

j. Isolation of noise sources.


Sound

Sound is produced when a sound source sets the air nearest to it in wave motion. The motion spreads to air particles far from the sound source. Sound travels in air at a speed of about 340 meters per second. The rate of travel is greater in liquids and solids; for example, 1,500 m/s in water and 5,000 m/s in steel.


Frequency

The frequency of a sound wave refers to the number of vibrations per second, measured in units of hertz (Hz). Sound is found within a large frequency range; audible sound for young persons is between about 20 Hz and 20,000 Hz.

The boundary between high and low frequencies is generally established at 1,000 Hz.

Sound may consist of a single pure tone, but in general it is made up of several tones of varying intensities.


Noise

It is customary to call any undesirable sound "noise." The disturbing effects of noise depend both on the intensity and the frequency of the tones. For example, higher frequencies are more disturbing than low ones. Pure tones are more disturbing than a sound made up of many tones.


Decibel

Sound levels are measured in units of decibels (dB). If sound is intensified by 10 dB, it seems to the ears approximately as if the sound intensity has doubled. A reduction by 10 dB makes it seem as if the intensity has been reduced by half.


Noise level measurement

In measuring sound levels, instruments are used which resemble the human ear in sensitivity to noise composed of varying frequencies. The instruments measure the "A-weighted sound level" in units called dB(A).  Workplace noise measurements indicate the combined sound levels of tool noise from a number of sources (machinery and materials handling) and background noise (from ventilation systems, cooling compressors, circulation pumps, etc.).

In order to accurately identify all workplace noise problems, the noise from each source should also be measured separately. Measurements at various production rates may be useful in considering possible control measures.


Dosimetry

Noise dose is computed when the sound level, L, is constant over the entire work shift, the noise dose, D, in percent, is given by: D=100 C/T where C is the total length of the work day, in hours, and T is the reference duration corresponding to the measured sound level, L, as given in the following formula:

T = 8/2(L-90)/5

T is the reference duration and is computed as above where L is the measured A-weighted sound level.

The dosimetry reading for determination of compliance is made according to the amount of exposure to noise in the workplace. The amount of such exposure is measured with an audiodosimeter which gives a readout in terms of "dose." To convert the reading of a dosimeter into a time-weighted average sound level one must refer to Table A-1 listed in 29 CFR 1910.95 of the OSHA standard. So, for

example, a dose of 91 percent over an eight hour day results in a TWA of 89.3 dB, and a dose of 50 percent corresponds to a TWA of 85 dB when referenced to the aforementioned table.

If the dose as read on the dosimeter is less than or greater than the values found in the Table, the TWA may be calculated by using the formula: TWA = 16.61 log10 (D/100)+90 where TWA = 8-hour time-weighted average sound level and D=accumulated dose in percent exposure.