Purpose and Scope
The purpose of these standards is to prevent the occurrence
and reduce the progression of occupational noise-induced
hearing loss among miners. This part sets forth mandatory
health standards for each surface and underground metal,
nonmetal, and coal mine subject to the Federal Mine Safety
and Health Act of 1977. The provisions of this part become
effective September 13, 1999.
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Definitions (30 CFR § 62.101)
The following definitions apply in this part:
Access - The right to examine and copy records.
Action Level
- An 8-hour time-weighted average sound level (TWA8) of
85 dBA, or equivalently a dose of 50%, integrating all sound
levels from 80 dBA to at least 130 dBA.
Audiologist -
A professional, specializing in the study and rehabilitation
of hearing, who is certified by the American Speech-Language-Hearing
Association (ASHA) or licensed by a state board of examiners.
Baseline Audiogram
- The audiogram recorded in accordance with §62.170(a)
of this part against which subsequent audiograms are compared
to determine the extent of hearing loss.
Criterion Level
- The sound level which if constantly applied for 8 hours
results in a dose of 100% of that permitted by the standard.
Decibel (dB)
- A unit of measure of sound pressure levels, defined in
one of two ways, depending upon the use:
(1) For measuring
sound pressure levels, the decibel is 20 times the common
logarithm of the ratio of the measured sound pressure
to the standard reference sound pressure of 20 micropascals
(µPa), which is the threshold of normal hearing
sensitivity at 1000 Hertz (Hz).
(2) For measuring
hearing threshold levels, the decibel is the difference
between audiometric zero (reference pressure equal to
0 hearing threshold level) and the threshold of hearing
of the individual being tested at each test frequency.
Dual Hearing Protection Level
- A TWA8 of 105 dBA, or equivalenly, a dose of 800% of that
permitted by the standard, integrating all sound levels
from 90 dBA to at least 140 dBA.
Exchange Rate
- The amount of increase in sound level, in decibels, which
would require halving of the allowable exposure time to
maintain the same noise dose. For the purposes of this part,
the exchange rate is 5 decibels (5 dB).
Hearing protector
- Any device or material, capable of being worn on the head
or in the ear canal, sold wholly or in part on the basis
of its ability to reduce the level of sound entering the
ear, and which has a scientifically accepted indicator of
noise reduction value.
Hertz (Hz)
- Unit of measurement of frequency numerically equal to
cycles per second.
Medical Pathology
- A condition or disease affecting the ear.
Miner's designee
- Any individual or organization to whom a miner gives written
authorization to exercise a right of access to records.
Qualified technician
- A technician who has been certified by the Council for
Accreditation in Occupational Hearing Conservation (CAOHC),
or by another recognized organization offering equivalent
certification.
Permissible Exposure Level -
A TWA8 of 90 dBA or equivalently a dose of 100% of that
permitted by the standard, integrating all sound levels
from 90 dBA to at least 140 dBA.
Reportable Hearing Loss
- A change in hearing sensitivity for the worse, relative
to the miner's baseline audiogram, or the miner's revised
baseline audiogram where one has been established in accordance
with § 62.170(c)(2), of an average of 25 dB or more
at 2000, 3000, and 4000 Hz in either ear.
Revised baseline audiogram
- An annual audiogram designated to be used in lieu of a
miner's original baseline audiogram in measuring changes
in hearing sensitivity as a result of the circumstances
set forth in §§ 62.170(c)(1) or 62.170(c)(2) of
this part.
Sound level- The sound pressure level in decibels
measured using the A-weighting network and a slow response,
expressed in the unit dBA.
Standard threshold shift - A change in hearing sensitivity
for the worse relative to the miner's baseline audiogram,
or relative to the most recent revised baseline audiogram
where one has been established, of an average of 10 dB or
more at 2000, 3000, and 4000 Hz in either ear.
Time-weighted average-8 hour (TWA8). The sound level
which, if constant over 8 hours, would result in the same
noise dose as is measured.
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Noise Exposure Assessment (30 CFR
§ 62.110)
Editorial Note: This section became effective September
13, 2000.
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The mine operator must establish a system of monitoring
that evaluates each miner's noise exposure sufficiently
to determine continuing compliance with this part.
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The mine operator must determine a miner's noise dose
(D, in percent) by using a noise dosimeter or by computing
the formula: D = 100(C1/T1 + C2/T2 + .... + Cn/Tn),
where Cn is the total time the miner is exposed at a
specified sound level, and Tn is the reference duration
of exposure at that sound level shown in Table 62-1.
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The mine operator must use Table 62-2 when converting
from dose readings to equivalent TWA8 readings.
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A miner's noise dose determination must:
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be made without adjustment for the use of any
hearing protector;
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integrate all sound levels over the appropriate
range;
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reflect the miner's full work shift;
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use a 90-dB criterion level and a 5-dB exchange
rate; and
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use the A-weighting and slow response instrument
settings.
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Observation of monitoring. The mine
operator must provide affected miners and their representatives
with an opportunity to observe noise exposure monitoring
required by this section and must give prior notice
of the date and time of intended exposure monitoring
to affected miners and their representatives.
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Miner notification. The mine operator
must notify a miner of his or her exposure when the
miner's exposure is determined to equal or exceed the
action level, exceed the permissible exposure level,
or exceed the dual hearing protection level, provided
the mine operator has not notified the miner of an exposure
at such level within the prior 12 months. The mine operator
must base the notification on an exposure evaluation
conducted either by the mine operator or by an authorized
representative of the Secretary of Labor. The mine operator
must notify the miner in writing within 15 calendar
days of:
-
the exposure determination; and
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the corrective action being taken.
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The mine operator must maintain a copy of any such
miner notification, or a list on which the relevant
information about that miner's notice is recorded, for
the duration of the affected miner's exposure at or
above the action level and for at least 6 months thereafter.
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Action Level (30 CFR § 62.120)
If during any work shift a miner's noise exposure equals
or exceeds the action level the mine operator must enroll
the miner in a hearing conservation program that complies
with § 62.150 of this part.
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Permissible Exposure Level (30
CFR § 62.130)
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The mine operator must assure that no miner is exposed
during any work shift to noise that exceeds the permissible
exposure level. If during any work shift a miner's noise
exposure exceeds the permissible exposure level, the
mine operator must use all feasible engineering and
administrative controls to reduce the miner's noise
exposure to the permissible exposure level, and enroll
the miner in a hearing conservation program that complies
with § 62.150 of this part. When a mine operator
uses administrative controls to reduce a miner's exposure,
the mine operator must post the procedures for such
controls on the mine bulletin board and provide a copy
to the affected miner.
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If a miner's noise exposure continues to exceed the
permissible exposure level despite the use of all feasible
engineering and administrative controls, the mine operator
must continue to use the engineering and administrative
controls to reduce the miner's noise exposure to as
low a level as is feasible.
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The mine operator must assure that no miner is exposed
at any time to sound levels exceeding 115 dBA, as determined
without adjustment for the use of any hearing protector.
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Dual Hearing Protection Level (30
CFR § 62.140)
If during any work shift a miner's noise exposure exceeds
the dual hearing protection level, the mine operator must,
in addition to the actions required for noise exposures
that exceed the permissible exposure level, provide and
ensure the concurrent use of both an ear plug and an ear
muff type hearing protector. The following table sets out
mine operator actions under MSHA's noise standard.
| Provision |
Condition |
Action Required by the Mine Operator |
| § 62.120 |
Miner's noise exposure is less than
the action level |
None |
| § 62.120 |
Miner's exposure equals or exceeds
the action level, but does not exceed the permissible
exposure level (PEL) |
Operator enrolls the miner in hearing
conservation program (HCP) which includes (1) a system
of monitoring, (2) voluntary, with two exceptions,
use of operator-provided hearing protectors, (3) voluntary
audiometric testing, (4) training, and (5) record
keeping. |
| § 62.130 |
Miner's exposure exceeds the PEL |
Operator uses/continues to use all
feasible engineering and administrative controls to
reduce exposure to PEL; enrolls the miner in a HCP
including ensured use of operator-provided hearing
protectors; posts administrative controls and provides
copy to affected miner; must never permit a miner
to be exposed to sound levels exceeding 115 dBA. |
| § 62.140 |
Miner's exposure exceeds the dual
hearing protection level |
Operator enrolls the miner in a
HCP, continues to meet all the requirements of §
62.130, ensures concurrent use of earplug and earmuff. |
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Hearing Conservation Program (30
CFR § 62.150)
A hearing conservation program established under this part
must include:
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a system of monitoring under § 62.110 of this
part;
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the provision and use of hearing protectors under §
62.160 of this part;
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audiometric testing under §§ 62.170 through
62.175 of this part;
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training under § 62.180 of this part; and
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recordkeeping under § 62.190 of this part
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Hearing Protectors (30 CFR §
62.160)
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A mine operator must provide a hearing protector to
a miner whose noise exposure equals or exceeds the action
level under § 62.120 of this part. In addition,
the mine operator must:
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train the miner in accordance with § 62.180
of this part;
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allow the miner to choose a hearing protector from
at least two muff types and two plug types, and
in the event dual hearing protectors are required,
to choose one of each type;
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ensure that the hearing protector is in good condition
and is fitted and maintained in accordance with
the manufacturer's instructions;
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provide the hearing protector and necessary replacements
at no cost to the miner; and
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allow the miner to choose a different hearing protector(s),
if wearing the selected hearing protector(s) is
subsequently precluded due to medical pathology
of the ear.
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The mine operator must ensure, after satisfying the
requirements of paragraph (a) of this section, that
a miner wears a hearing protector whenever the miner's
noise exposure exceeds the permissible exposure level
before the implementation of engineering and administrative
controls, or if the miner's noise exposure continues
to exceed the permissible exposure level despite the
use of all feasible engineering and administrative controls.
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The mine operator must ensure, after satisfying the
requirements of paragraph (a) of this section, that
a miner wears a hearing protector when the miner's noise
exposure is at or above the action level, if:
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the miner has incurred a standard threshold shift;
or
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more than 6 months will pass before the miner can
take a baseline audiogram.
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Audiometric Testing (30 CFR §
62.170 )
The mine operator must provide audiometric tests to satisfy
the requirements of this part at no cost to the miner. A
physician or an audiologist, or a qualified technician under
the direction or supervision of a physician or an audiologist
must conduct the tests.
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Baseline audiogram. The mine operator
must offer miners the opportunity for audiometric testing
of the miner's hearing sensitivity for the purpose of
establishing a valid baseline audiogram to compare with
subsequent annual audiograms. The mine operator may
use an existing audiogram of the miner's hearing sensitivity
as the baseline audiogram if it meets the audiometric
testing requirements of § 62.171 of this part.
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The mine operator must offer and provide within
6 months of enrolling the miner in a hearing conservation
program, audiometric testing which results in a
valid baseline audiogram, or offer and provide the
testing within 12 months where the operator uses
mobile test vans to do the testing.
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The mine operator must notify the miner to avoid
high levels of noise for at least 14 hours immediately
preceding the baseline audiogram. The mine operator
must not expose the miner to workplace noise for
the 14-hour quiet period before conducting the audiometric
testing to determine a baseline audiogram. The operator
may substitute the use of hearing protectors for
this quiet period.
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The mine operator must not establish a new baseline
audiogram or a new revised baseline audiogram, where
one has been established, due to changes in enrollment
status in the hearing conservation program. The
mine operator may establish a new baseline or revised
baseline audiogram for a miner who is away from
the mine for more than 6 consecutive months.
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Annual audiogram. After the baseline
audiogram is established, the mine operator must continue
to offer subsequent audiometric tests at intervals not
exceeding 12 months for as long as the miner remains
in the hearing conservation program.
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Revised baseline audiogram. An annual
audiogram must be deemed to be a revised baseline audiogram
when, in the judgment of the physician or audiologist:
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a standard threshold shift revealed by the audiogram
is permanent; or
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the hearing threshold shown in the annual audiogram
indicates significant improvement over the baseline
audiogram.
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Notification of Results (30 CFR
§ 62.175)
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The mine operator must, within 10 working days of receiving
the results of an audiogram, or receiving the results
of a follow-up evaluation required under § 62.173
of this part, notify the miner in writing of:
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the results and interpretation of the audiometric
test, including any finding of a standard threshold
shift or reportable hearing loss; and
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the need and reasons for any further testing or
evaluation, if applicable.
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When evaluation of the audiogram shows that a miner
has incurred a reportable hearing loss as defined in
this part, the mine operator must report such loss to
MSHA as a noise-induced hearing loss in accordance with
part 50 of this title, unless a physician or audiologist
has determined that the loss is neither work-related
nor aggravated by occupational noise exposure.
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Training (30 CFR § 62.180)
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The mine operator must, within 30 days of a miner's
enrollment into a hearing conservation program, provide
the miner with training. The mine operator must give
training every 12 months thereafter if the miner's noise
exposure continues to equal or exceed the action level.
Training must include:
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the effects of noise on hearing;
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the purpose and value of wearing hearing protectors;
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the advantages and disadvantages of the hearing
protectors to be offered;
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the various types of hearing protectors offered
by the mine operator and the care, fitting, and
use of each type;
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the general requirements of this part;
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the mine operator's and miner's respective tasks
in maintaining mine noise controls; and
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the purpose and value of audiometric testing and
a summary of the procedures.
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The mine operator must certify the date and type of
training given each miner, and maintain the miner's
most recent certification for as long as the miner is
enrolled in the hearing conservation program and for
at least 6 months thereafter.
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Records (30 CFR § 62.190)
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The authorized representatives of the Secretaries of
Labor and Health and Human Services must have access
to all records required under this part. Upon written
request, the mine operator must provide, within 15 calendar
days of the request, access to records to:
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the miner, or with the miner's written consent,
the miner's designee, for all records that the mine
operator must maintain for that individual miner
under this part;
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any representative of miners designated under part
40 of this title, to training certifications compiled
under § 62.180(b) of this part and to any notice
of exposure determination under § 62.110(d)
of this part, for the miners whom he or she represents;
and
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any former miner, for records which indicate his
or her own exposure.
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When a person with access to records under paragraphs
(a)(1), (a)(2), or (a)(3) of this section requests a
copy of a record, the mine operator must provide the
first copy of such record at no cost to that person,
and any additional copies requested by that person at
reasonable cost.
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Transfer of records.
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The mine operator must transfer all records required
to be maintained by this part, or a copy thereof,
to a successor mine operator who must maintain the
records for the time period required by this part.
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The successor mine operator must use the baseline
audiogram, or revised baseline audiogram, as appropriate,
obtained by the original mine operator to determine
the existence of a standard threshold shift or reportable
hearing loss. Appendix to part 62.
Table 61-1:
Reference Duration |
| dBA |
T(hrs) |
| 80 |
32.0 |
| 85 |
16.0 |
| 86 |
13.9 |
| 87 |
12.1 |
| 88 |
10.6 |
| 90 |
8.0 |
| 91 |
7.0 |
| 92 |
6.1 |
| 93 |
5.3 |
| 94 |
4.6 |
| 95 |
4.0 |
| 96 |
3.5 |
| 97 |
3.0 |
| 98 |
2.6 |
| 99 |
2.3 |
| 100 |
2.0 |
| 101 |
1.7 |
| 102 |
1.5 |
| 103 |
1.3 |
| 104 |
1.1 |
| 105 |
1.0 |
| 106 |
0.87 |
| 107 |
0.76 |
| 108 |
0.66 |
| 109 |
0.57 |
| 110 |
0.50 |
| 111 |
0.44 |
| 112 |
0.38 |
| 113 |
0.33 |
| 114 |
0.29 |
| 115 |
0.25 |
At no time shall any excursion exceed 115 dBA. For
any value, the reference duration (T) in hours is computed
by: T = 8/2(L-90)5 where L is the measured A-weighted,
slow-response sound pressure level.
Table 62.2 "Dose"/
TWA8 Equivalent |
Dose
(%) |
TWA8 |
| 25 |
80 |
| 29 |
81 |
| 33 |
82 |
| 38 |
83 |
| 44 |
84 |
| 50 |
85 |
| 57 |
86 |
| 66 |
87 |
| 76 |
88 |
| 87 |
89 |
| 100 |
90 |
| 115 |
91 |
| 132 |
92 |
| 152 |
93 |
| 174 |
94 |
| 200 |
95 |
| 230 |
96 |
| 264 |
97 |
| 303 |
98 |
| 350 |
99 |
| 400 |
100 |
| 460 |
101 |
| 530 |
102 |
| 610 |
103 |
| 700 |
104 |
| 800 |
105 |
| 920 |
106 |
| 1056 |
107 |
| 1213 |
108 |
| 1393 |
109 |
| 1600 |
110 |
| 1838 |
111 |
| 2111 |
112 |
| 2425 |
113 |
| 2786 |
114 |
| 3200 |
115 |
Interpolate between the values found in this Table,
or extend the Table, by using the formula:TWA8
= 16.61 log10 (D/100) + 90.
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