EPA Hearing Protector Labels

The Environmental Protection Agency (EPA) requires that hearing protectors be labeled to show their effectiveness. Compliance with these requirements involves labeling, testing, recordkeeping and related duties which are the responsibility of the manufacturers. The information supplied is intended for the benefit of those who purchase and use the protectors. The employer who is responsible for reducing employee noise exposure to requires limits can make good use of the new label information.

The EPA is requiring that both a primary label and sup-porting information be supplied with hearing protectors. The primary label gives the noise reduction rating of the product; the supporting information covers additional factors affecting actual performance of the device such as proper fit, durability of the protector and effectiveness at specific frequencies.

The noise reduction rating (NRR) is intended to show the effectiveness of the protector in terms of decibels of noise attenuation. Several variables have been taken into account in the NRR, such as differing noise spectra and fit variability. In most cases, therefore, the exposure of employees wearing the protector closely approximates the value obtained by subtracting the NRR from the A-weighted noise level. If, for example, a bearing protective device with an NRR of 15 were purchased and if the device were properly worn in a noise level of 100 dB(A), the noise level perceived by the ear would be 85 dB(A). Earmuffs and semiaural devices will have NRR ratings between approximately 15 and 25. Premolded and custom-molded plugs will be between 10 and 25. Foam earplugs will be 29 and disposable plugs will be approximately 20. If noise exposure consists mainly of frequencies below 500 Hz, however, the NRR should be subtracted from the A-weighted noise level. Hearing protectors of the type which do not begin So attenuate noise until a specific sound pressure level is reached do not register on the test wed to establish the NRR. The EPA is requiring manufacturers of these protectors to devise a suitable test and rating

system for their products. For ear muff type protectors designed to be worn with the headband in different positions, the actual attenuation can vary. The label must show the lowest NRR that the device would provide and which of the positions gives this value.

In addition to the protector's own noise reduction rating, the label also shows where the protector stands in comparison to other devices. The EPA is requiring that each label show the range of attenuation available from hearing protectors on the market. In selecting a protector, therefore, the attenuation needed would be compared with the NRR and the range of ratings to determine if the device at hand would be suitable or if another device is available that would be better for the purpose.

The supporting information which must also be provided with the protector consists of more detailed attenuation data, precautions and other information on how to obtain the protection expected. The detailed attenuation data must include the mean attenuation values for each test frequency and the NRR calculated from those values. For ear muff type protectors which can be used in more than one position, the NRR values for all positions must be given. A Statement to the effect that improper fit will reduce effectiveness along with instructions on how to fit or insert the device properly must be included. To prevent misuse, a warning regarding the use of hearing protectors to prevent the harmful effects of impulsive noise must state that "the Noise Reduction Rating (NRR) is based on the attenuation of continuous noise and may not be an accurate indicator of the protection attainable against impulsive noise such as gunfire."

In its publication Questions & Answers to Part 1910, OSHA states that hearing protectors should be selected from those which have a sound attenuation curv⁵ guaranteed by the manufacturer. The new EPA labels will assure that reliable information is available for all hearing protectors.