[Federal Register Volume 64, Number 176 (Monday, September 13, 1999)]
[Rules and Regulations]
[Pages 49636-49637]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-23962]



[[Page 49635]]

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Part III





Department of Labor





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30 CFR Parts 56, 57, 62, 70 and 71



Occupational Noise Exposure Final Rule; Correction

  Federal Register / Vol. 64, No. 176 / Monday, September 13, 1999 / 
Rules and Regulations  

[[Page 49636]]



DEPARTMENT OF LABOR

Mine Safety and Health Administration

30 CFR Parts 56, 57, 62, 70 and 71

RIN 1219-AA53


Occupational Noise Exposure; Correction

AGENCY: Mine Safety and Health Administration, Labor.

ACTION: Final rule; correction.

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SUMMARY: This document corrects the preamble to the final rule for 
health standards for occupational noise exposure published elsewhere in 
today's Federal Register.

FOR FURTHER INFORMATION CONTACT: Carol J. Jones, Acting Director, 
Office of Standards, Regulations, and Variances, MSHA, (703) 235-1910.

Correction

    MSHA is publishing elsewhere in this issue of the Federal Register 
a final rule on health standards for occupational noise exposure. This 
document adds text inadvertently left out of the preamble. Certain text 
that should have been included under the heading ``Section 62.130  
Permissible exposure level'' was inadvertently omitted. The text should 
have followed this paragraph:

    Although many commenters may prefer to use hearing protectors in 
lieu of engineering or administrative controls to protect miners 
from noise overexposures, MSHA has concluded that the scientific 
evidence does not support this position, and that the approach taken 
in the final rule best protects miners from further noise-induced 
hearing loss.

    The text to be added reads as follows:
    MSHA noted earlier in this discussion that it had conducted a study 
of the noise reduction values of hearing protectors in the actual 
mining environment. The inability to accurately predict the noise 
reduction provided by a hearing protector to an individual miner led to 
MSHA's decision to reject the use of hearing protectors as the primary 
means of reducing a miner's noise exposure to the permissible exposure 
level. Not only do engineering and administrative controls best protect 
miners from noise-induced hearing loss, they increase the protection 
afforded by a hearing protector.
    One commenter requested that MSHA provide a definition of an 
engineering noise control. MSHA addresses engineering controls in 
significant detail under the discussion of feasibility in Part VI of 
this preamble.
    Several commenters wanted MSHA to recognize the noise-cancellation 
ear muff as an engineering noise control. Noise-cancellation ear muffs 
are hearing protectors that are designed to generate sound that cancels 
harmful noise signals under the cup of the ear muff. MSHA has not found 
any data substantiating a standardized method of evaluating the 
efficacy of noise-cancellation ear muffs in a manner similar to 
engineering controls. Also, noise-cancellation ear muffs in the active 
mode cannot be evaluated using the American National Standards 
Institute (ANSI) method for evaluating hearing protectors. Noise-
cancellation ear muffs are not engineering controls, and the final rule 
does not accept them as such but does recognize them as hearing 
protectors, where an NRR value has been assigned under EPA regulations.
    Some other commenters believed that the use of operator cabs, which 
are engineering controls that allow the miner to work within a 
protective sound enclosure, creates a safety hazard, especially in low-
seam underground mines. Although the Agency has limited experience with 
the use of noise-control cabs in underground mines, MSHA has had 
extensive experience with the use of cabs in underground mines to 
provide protection from falling objects, including roof falls. This 
experience demonstrates that equipment cabs can be safely used in the 
underground mine environment. In any case, MSHA would not expect a mine 
operator to use a cab as an engineering control if it created a safety 
hazard. As a practical matter, the final rule provides mine operators 
with significant flexibility in choosing among various noise controls, 
and does not compel the use of one type of control over another.
    Many commenters believe administrative controls create unnecessary 
problems for mine operators. Some of their concerns include 
restrictions in labor contracts, the limited numbers of qualified 
miners who can be rotated in and out of a job, and the difficulty in 
tracking rotated miners. MSHA has concluded that the effectiveness of 
administrative controls, when they are feasible, compels their 
application prior to allowing mine operators to use personal hearing 
protectors to control their miners' noise exposures.
    Regarding the feasibility of noise controls, the American Portland 
Cement Alliance commented that there are several operational areas 
where it is particularly difficult and expensive to control noise, for 
example raw and finish ball mills, crusher and screening areas, and 
coal unloading, compressor and blower rooms. In one example, the 
commenter estimated that it would cost ``hundreds of thousands of 
dollars'' in manpower, materials, lost production and equipment, to 
retrofit rubber liners in the interior walls of the mills. The 
commenter also noted that alternative means of milling would cost 
between 3-million and 10-million dollars per ball mill. Section VI of 
this preamble discusses the feasibility of a permissible exposure level 
for the mining industry, and, in addition, the feasibility of complying 
with the permissible exposure level for a particular operator. 
Regarding noise controls which may be feasible for particular operators 
of milling operations, the Agency intends to adhere to the enforcement 
guidelines set forth in volume IV of its existing program policy manual 
because the permissible exposure level in the final rule remains 
unchanged from the existing noise standards. The program policy manual 
indicates that frequently, mining personnel are exposed to noise levels 
of up to 114 dBA from milling operations, and that engineering noise 
controls may be feasible for such operations. Such controls include: 
resiliently backed liners; acoustically treated control booths; full or 
partial topless enclosures around mill equipment or employee work 
locations; and acoustic baffles suspended above enclosures. In order to 
determine which control or combination of controls are feasible and 
effective to reduce the noise exposure of employees working in mills, 
it is usually necessary to do a time study to pinpoint the locations 
and noise sources contributing to the employee's overexposure. In some 
situations an acoustically treated control booth may be all that is 
needed, in others more extensive treatments may be necessary. 
Administrative controls may also be feasible to limit employee exposure 
to particularly noisy areas of a mill.
    Control booths can be constructed and acoustically treated by mine 
operators or can be purchased from commercial sources. Resiliently 
backed liners can be put on chutes, bins and other drop or impact 
points to reduce noise from these sources. In situations where numerous 
employees are exposed to the noise, full or partial topless enclosures 
around the mill may be feasible. Dependent upon the noise reduction 
required to lower an employee's exposure to the permissible exposure 
level, acoustical absorptive material may be needed within or above the 
enclosure. Acoustical baffles suspended above such enclosures has 
proven to be an effective method of reducing the overall noise levels.
    The cost for such enclosures is dependent on the type of materials 
utilized in its construction and the

[[Page 49637]]

overall size of the enclosure. In three demonstrations of this 
technology, total material costs have ranged between $3500 and $7000. 
MSHA intends to assess, on a case-by-case basis, whether engineering 
and administrative controls are feasible at a particular mine that is 
experiencing an overexposure.

    Dated: September 9, 1999.
Carol J. Jones,
Acting Director, Office of Standards, Regulations, and Variances.
[FR Doc. 99-23962 Filed 9-10-99; 8:45 am]
BILLING CODE 4510-43-P