Noise hearing protectors

A baseline audiogram shall be established on employees exposed at or above the action level within 6 months of the first exposure. Employees shall be notified of the requirement that testing shall be preceded by at least 14 hours without exposure to workplace noise. Hearing protectors may be worn as a substitute to this requirement. 

Noise must be comply with the Noise at Work Regulations and ear protectors with BS 6344, Industrial hearing protectors. 

The NRR is a single-number rating method that attempts to describe a hearing protector based on how much the overall noise level is reduced by the hearing protector. The NRR is required by law to be shown on the label of each hearing protector sold in the United States. The NRR is specified by 40 CFR, Part 211, Product Noise Labeling, Subpart B. 

S3.19-1974, American National Standard for the Measurement of Real-Ear Hearing Protector Attenuation and Physical Attenuation of Earmuffs. When estimating A-weighted noise exposures, it is important to remember to first subtract 7 dB from the NRR and then subtract the remainder from the A-weighted noise level. The NRR theoretically provides an estimate of the protection that should be met or exceeded by 98 percent of the wearers of a given device. In practice, this does not prove to be the case, so a variety of methods for de-rating the NRR have been discussed. Non-auditory Effects of Noise... 

List the dBA levels of various equipment and tasks. For example, rock drilling can reach 115 dBA, chain saws 125 dBA, abrasive blasting 112 dBA, heavy equipment 110 dBA, demolition 117 dBA, and needle guns 112 dBA. Show slides of the equipment/tasks that require hearing protectors. Dispell myths about workers getting used to the noise. Have samples of all approved hearing protective devices. Indicate where workers can find hearing protectors. 

The Environmental Protection Agency has a noise reduction rating (NRR) and labeling standards for hearing protectors.These standards provide a reliable way to rate hearing protectors. As noted, the performance also depends on fit. NRR applies to continuous noise and may not represent the noise reduction from impulse noise. A NRR of 10... 

In addition, depending on the type of chemicals and type of exposure, the respiratory tract should also be protected against inhalation of airborne contaminants, which can be in the form of particles, vapors or gases. Also, hearing protectors should not be forgotten. The need to use hearing protectors starts when the noise level, in spite of engineering control measures, exceeds the national limit value, which is 90 or 85 dB in many countries (Korhonen 1997). 

Hearing protectors only reduce the amount of noise that gets through to the ears. The amount of this reduction is referred to as attenuation. Attenuation differs... 

Hearing protectors should be chosen to reduce the noise level at the wearer s ear to below the recommended limit for unprotected exposure (e.g. to 85 dBA which is a practicably achievable figure in almost all industrial situations). This cannot be done from simple A-weighted measurements of the noise level, because sound reduction will depend upon its frequency spectrum. Octave band analysis will provide the necessary information to be matched against the overall sound attenuation of different hearing protectors which is claimed by the manufacturers in their test data. 

The provision of each overexposed employee with an individually fitted hearing protector with an adequate noise reduction rating. 

Noise Reduction Rating—A rating given as a laboratory based indicator of the relative effectiveness of hearing protectors. 

It is incumbent upon safety professionals to educate employers and employees alike to avoid commonly made mistakes, such as f Misjudging noise levels Choosing a hearing protector based solely on attenuation characteristics... 

Most employers do not know the frequency of the noise in their workplace, so the NRR grade or class rating of the hearing protectors provides a guideline forjudging which level of protection is best matched... 

Noise Reduction Rating or NRR — all hearing protectors carry a label indicating the NRR a higher number on the label means more effectiveness. 

In general, earplugs can reduce noise reaching the ear by 25 to 30 dB. Earmuffs can reduce noise 20 to 25 dB. Combinations of the two protectors can give 3 to 5 dB more protection. No matter what t5q>e of protection device you select, remember that the only effective hearing protector is the one that you wear ... 

Data about the ability of equipment to protect against a particular hazard is provided by manufacturers who carry out tests under controlled conditions which are often specified in national or international standards. Performance requirements for face masks, for example, are contained in two British Standards which specify the performance requirements of full-face and half/quarter masks for respiratory protective equipment. The method used to determine the noise attenuation of hearing protectors at different frequencies (octave bands) throughout the audiWe range is specified in a European standard . 

LBVBI 2 - Approved hearing protectors are available however, preformed (sized) earplugs are primarily maintained in noise-hazardous areas, but not all sizes are available. Choices from approved hearing protectors are limited by incomplete inventories. 

LBVBI 5 - User considerations of comfort, ease of use, compatibility with other equipment and communication requirements are given equal weight to noise reduction characteristics in the selection and availability of hearing protectors. 

Several types of effective earmuffs and/or earplugs should be made available to employees. They should be selected based on the type of noise to be attenuated and the degree of noise attenuation needed. They should also be comfortable to wear and easy to use. It is important that plant management support and encourage their use whenever workers enter noisy areas. Hearing protectors only work when worn properly ... 

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