ADOSH-SF Code of Practice CoP 3.0 - Occupational Noise

Article-level navigation isn't available for this document — showing the full text as extracted.

Abu Dhabi Occupational Safety and
Health System Framework
(ADOSH-SF)
Code of Practice
CoP 3.0 – Occupational Noise
Version 4.0
July 2024

ADOSH-SF – Codes of Practice - CoP 3.0 – Occupational Noise
Version 4.0 – 15 th July 2024 Page 2 of 24
Table of Contents
1. Introduction ...................................................................................................................................................... 3
2. Training and Competency ........................................................................................................................... 4
3. Requirements .................................................................................................................................................. 5
3.1. Roles and Responsibilities ................................................................................................................. 5
3.2. Noise Risk Assessment....................................................................................................................... 6
3.3. Hearing Conservation Program........................................................................................................ 7
3.4. Noise Hazard Signage ....................................................................................................................... 11
3.5. Audiometric Measuring Instruments ........................................................................................... 11
3.6. Audiometric Test Rooms .................................................................................................................. 12
3.7. Computation of Employee Noise Exposure ............................................................................... 12
3.8. Computation of Hearing Protection Attenuation ................................................................... 13
4. Record Keeping ............................................................................................................................................. 14
5. References ..................................................................................................................................................... 15
6. Document Amendment Record ............................................................................................................... 16
APPENDIX 1: Allowable Duration of Exposure Based on Sound Level dB(A) ................................. 17
APPENDIX 2: Calculating dB(A) Using Octave Band Analysis Data .................................................... 18
APPENDIX 3: Calculation of Allowable Noise: ........................................................................................... 20
APPENDIX 4: Computation of Hearing Protection Attenuation ......................................................... 21

ADOSH-SF – Codes of Practice - CoP 3.0 – Occupational Noise
Version 4.0 – 15 th July 2024 Page 3 of 24
1. Introduction
(a) This Code of Practice (CoP) applies to all employers within the Emirate of Abu
Dhabi. This CoP is designed to incorporate requirements set by UAE and Abu Dhabi
Regulatory Authorities. If requirements of this document conflict with requirements
set by another regulatory authority, employers are required to follow the more
stringent requirement.
(b) This CoP establishes the requirements and standards so that the risks associated
where employees, contractors or visitors could be exposed to noise levels at or in
excess of 85 decibels (dB) as measured on an A-weighted scale at any time during a
work shift are managed in an appropriate manner.

ADOSH-SF – Codes of Practice - CoP 3.0 – Occupational Noise
Version 4.0 – 15 th July 2024 Page 4 of 24
2. Training and Competency
(a) Employers shall ensure that OSH training complies with the requirements of:
(i) ADOSH-SF – Element 5 – Training, Awareness and Competency;
(ii) ADOSH-SF – Mechanism 7.0 – Occupational Safety and Health Practitioner and
Service Provider Registration.
(b) Employers shall provide training to all employees exposed to noise at or in excess of
an 8-hr time weighted average of 85 dB(A). Training shall be conducted within 30
days of starting work and prior to working in a high noise area, and include:
(i) requirements of this CoP;
(ii) health hazards associated with exposure to noise above 85 dB(A);
(iii) signs and symptoms of noise exposure and hearing loss;
(iv) types of hearing loss;
(v) information on the employer’s hearing conservation program;
(vi) the purpose of hearing protectors along with the advantages, disadvantages, and
attenuation of various types of hearing protectors;
(vii) instructions on selection, fitting, use, and care of hearing protectors;
(viii) purpose of audiometric testing and explanation of the testing procedures; and
(ix) locations within the facility where noise hazards exists and hearing protection is
required.
(c) Training provided shall include practical and theoretical training.
(d) Training shall be conducted in a language and method appropriate for the workforce.
(e) Refresher training shall be provided at appropriate intervals and include the criteria
listed in Section 2(b) of this Cop.
(f) Employers shall maintain a record of the required training that contains the following:
(i) name and ID number;
(ii) Emirates ID number of the employee;
(iii) subject(s) of training;
(iv) date(s) of training; and
(v) person providing the training;
(g) Employers shall provide appropriate information, instruction and /or training to those
persons who are not at work, but are at risk from noise levels emitted from the
workplace.
(h) Employers shall ensure that any contractors who are working within the workplace,
and are exposed to noise levels at or above an 8-hr time weighted average of 85 dB(A)
have received appropriate training.

ADOSH-SF – Codes of Practice - CoP 3.0 – Occupational Noise
Version 4.0 – 15 th July 2024 Page 5 of 24
3. Requirements
3.1. Roles and Responsibilities
3.1.1. Employers
(a) Employers shall undertake their roles and responsibilities in accordance with the
general requirements of
ADOSH-SF – Element 1 – Roles, Responsibilities and Self-
Regulation Section 3.2.5.
(b) Employers shall eliminate noise hazards by purchasing low noise and vibration
producing equipment, maintaining equipment to manufacturer’s specifications,
erecting barriers, or implementing other control measures to eliminate / reduce noise
hazards, where reasonably practicable.
(c) Employers shall provide protection to employees, contractors and visitors against the
effects of noise exposure when the sound levels exceed those shown in Appendix 1
when measured on the A scale of a standard sound level meter at slow response.
When noise levels are determined by octave band analysis, the equivalent A-weighted
sound level may be determined using the procedure found in Appendix 2.
(d) Employers shall, when employees are subjected to exposure levels exceeding those
listed in Appendix 1, implement reasonably practicable engineering and/or
administrative control measures. If such control measures fail to reduce sound levels
within the levels of Appendix 1, personal protective equipment shall be provided and
used to reduce sound levels within the levels of the table.
Note: If the variations in noise level involve maxima at intervals of 1 second or less, it is to be considered
continuous.
(e) Employers shall ensure employees, contractors and visitors are not be exposed to any
continuous, intermittent, or impact noise levels at or in excess of a 100 dB(A), unless
the appropriate hearing protection is provided.
(f) Employers shall develop and implement a “Hearing Conservation Program” as per
Section 3.3 of this CoP when they have noise hazards that exceed 85 dB(A).
3.1.2. Employees
(a) Employees hall undertake their roles and responsibilities in accordance with the
general requirements of
ADOSH-SF – Element 1 – Roles, Responsibilities and Self-
Regulation Section 3.2.7.
(b) Employees shall report any activity or equipment defect relating to noise exposures
which they believe is reasonably practicable to cause any overexposure to themselves
or another person.
(c) Employees shall use appropriate hearing protection, equipment or safety devices
provided by the employer in accordance with any training or instruction received.

ADOSH-SF – Codes of Practice - CoP 3.0 – Occupational Noise
Version 4.0 – 15 th July 2024 Page 6 of 24
3.2. Noise Risk Assessment
(a) Employers who carry out work which is liable to expose any employees to noise at or
above the action level of 85 dB(A) shall make a suitable and sufficient assessment of
the risk, in line with the requirements of
ADOSH-SF - Element 2 – Risk Management,
from that noise to the safety and health of those employees, and the risk assessment
shall identify the measures which need to be taken to meet the requirements of this
CoP. Employers shall also assess exposure to any contractors or other persons that
may be affected by the noise emissions of the workplace.
(b) When undertaking the noise risk assessment, the employer shall assess the levels of
noise to which workers are exposed by:
(i) observation of specific working practices;
(ii) reference to relevant information on the probable levels of noise corresponding
to any equipment used in the particular working conditions; and
(iii) if necessary, measurement of the level of noise to which his employees are
likely to be exposed.
(c) Employers shall assess whether any employees are likely to be exposed to noise at or
above the exposure limits as detailed in Appendix 1 of this document.
(d) The risk assessment shall consider:
(i) the level, type and duration of exposure, including any exposure to peak sound
pressure;
(ii) the effects of exposure to noise on employees or groups of employees whose
health is at particular risk from such exposure;
(iii) so far as is practicable, any effects on the health and safety of employees
resulting from the interaction between noise and the use of ototoxic substances
at work, or between noise and vibration;
(iv) any indirect effects on the health and safety of employees resulting from the
interaction between noise and audible warning signals or other sounds that
need to be audible in order to reduce risk at work;
(v) any information provided by the manufacturers of work equipment;
(vi) the availability of alternative equipment designed to reduce the emission of
noise;
(vii) any extension of exposure to noise at the workplace beyond normal working
hours, including exposure in rest facilities supervised by the employer;
(viii) appropriate information obtained following health surveillance, including, where
possible, published information; and
(ix) the availability of personal hearing protectors with adequate attenuation
characteristics.
(e) The risk assessment shall be reviewed on a regular basis, at least annually and
following any significant changes within the workplace likely to affect the noise levels
employees are exposed to.

ADOSH-SF – Codes of Practice - CoP 3.0 – Occupational Noise
Version 4.0 – 15 th July 2024 Page 7 of 24
3.3. Hearing Conservation Program
(a) Employers shall administer a continuous, effective hearing conservation program, as
described in this section whenever noise exposures, as identified through a noise risk
assessment described in section 3.2 of this document, equals or exceed 85 decibels
measured on the A-weighted scale (slow response). For the purposes of the hearing
conservation program, employee noise exposures shall be computed in accordance
with Appendix 1 and/or Appendix 3, and without regard to any attenuation provided
by the use of personal protective equipment. Employers shall ensure no employee,
contractor or other person is exposed to any continuous, intermittent, or impact noise
at or in excess of 100dB(A) without the use of hearing protection.
(b) Employers hearing conservation programs shall consist of the following elements:
(i) exposure monitoring:
1. employers shall use a competent person to develop and implement a
monitoring program and sampling strategy to assess employee’s exposure
to noise;
2. the sampling strategy shall be designed to identify employees for inclusion
in the hearing conservation program and to enable the appropriate selection
of hearing protection;
3. where circumstances such as high employee mobility, significant variations
in sound level, or a significant component of impulse noise make area
monitoring generally inappropriate, the employer shall use representative
personal sampling to comply with the monitoring requirements of this
paragraph unless the employer can show that area sampling produces
equivalent results;
4. all continuous, intermittent and impulsive sound levels from 80 dB(A) to
130 dB(A) shall be integrated into the noise measurements;
5. instruments used to measure employee noise exposure shall be calibrated
as per manufacturer’s recommendations to ensure measurement accuracy;
6. monitoring shall be repeated whenever a change in production, process,
equipment or control measures increases noise exposures to the extent
that:
• additional employees may be exposed at or above the action level; or
• the attenuation provided by hearing protectors being used by
employees may be rendered inadequate to meet the requirements of
Section 3.3(b)(xii) of this CoP.
(ii) employee notification:
1. employers shall notify each employee exposed at or above an 8-hour time-
weighted average of 85 dB(A) of the results of the monitoring. Notification
shall be made in the language and method understood by the employee.
(iii) audiometric testing program:
1. employers shall establish and maintain an audiometric testing program as
provided in this paragraph by making audiometric testing available to all

ADOSH-SF – Codes of Practice - CoP 3.0 – Occupational Noise
Version 4.0 – 15 th July 2024 Page 8 of 24
employees whose exposures equal or exceed an 8-hour time-weighted
average of 85 dB(A);
2. the audiometric testing program shall be provided at no cost to the
employees; and
3. audiometric tests shall be performed by a licensed or certified audiologist,
otolaryngologist, or other physician, or by a technician that is
certified/accredited by DOH and who has satisfactorily demonstrated
competence in administering audiometric examinations, obtaining valid
audiograms, and appropriately using, maintaining and checking calibration
and appropriate functioning of the audiometers being used. A technician
who performs audiometric tests shall be responsible to an audiologist,
otolaryngologist or physician.
(iv) baseline audiogram:
1. within 6 months of an employee’s first exposure at or above 85 dB(A) of
noise, the employer shall establish a valid baseline audiogram against which
subsequent audiograms can be compared;
2. testing to establish a baseline audiogram shall be preceded by at least 14
hours without exposure to workplace noise. Hearing protectors may be
used as a substitute for the requirements that the baseline audiograms be
preceded by 14-hours without exposure to workplace noise; and
3. employers shall notify employees of the need to avoid high levels of non-
occupational noise exposure during the 14-hour period immediately
preceding the audiometric examination.
(v) annual audiogram:
1. within 12 months of an employee’s baseline audiogram, the employer shall
provide an audiogram that can be compared to the baseline audiogram and
subsequent audiograms;
2. testing to establish an annual audiogram shall be preceded by at least 14
hours without exposure to workplace noise. Hearing protectors may be
used as a substitute for the requirements that the baseline audiograms be
preceded by 14-hours without exposure to workplace noise; and
3. employers shall notify employees of the need to avoid high levels of non-
occupational noise exposure during the 14-hour period immediately
preceding the audiometric examination.
(vi) evaluation of audiogram:
1. each employee’s audiogram shall be compared to that employee’s baseline
audiogram to determine if the audiogram is valid and if a standard threshold
shift has occurred as defined by Section 3.3(b)(viii) of this CoP;
2. if the annual audiogram shows that an employee has suffered a standard
threshold shift, the employer may obtain a retest within 30 days and
consider the results of the retest as the annual audiogram;
3. an audiologist, otolaryngologist, or physician shall review problem
audiograms and they shall determine whether there is a need for further
evaluation. The employer shall provide to the person performing this
evaluation the following information:
• a copy of the requirements of this CoP;

ADOSH-SF – Codes of Practice - CoP 3.0 – Occupational Noise
Version 4.0 – 15 th July 2024 Page 9 of 24
• the baseline audiogram and most recent audiogram of the employee
to be evaluated;
• measurements of background sound pressure levels in the
audiometric test room as required in Section 3.5 of this document;
and
• records of audiometric calibrations as required by the equipment
manufacture.
(vii) follow-up procedures:
1. if a comparison of the annual audiogram to the baseline indicates a
standard threshold shift as defined in Section 3.3(b)(viii) of this document,
the employee shall be informed of this fact in writing, in a language the
employee will understand, within 21 days of the determination.
2. unless a physician determines that the standard threshold shift is not
work related or aggravated by occupational noise exposure, the employer
shall ensure that the following steps are taken when a standard threshold
shift occurs:
• employees shall be fitted/refitted with hearing protectors, trained in
their use and care, and required to use them;
• hearing protection in use shall be evaluated to ensure they are
offering the appropriate attenuation. If necessary, hearing protectors
shall be replaced with hearing protectors offering greater
attenuation;
• employees shall be referred for a clinical audio-logical evaluation or
an otological examination, as appropriate, if additional testing is
necessary or if the employer suspects that the medical pathology of
the ear is affected or aggravated by the wearing of hearing
protectors; and
• the employee is informed of the need for an otological examination if
the medical pathology of the ear that is unrelated to the use of
hearing protectors is suspected.
3. if subsequent audiometric testing of an employee indicates that a
standard threshold shift is not persistent, the employer shall inform the
employee of the new audiometric interpretation.
(viii) standard threshold shift:
1. as per this CoP, a standard threshold shift is a change in hearing threshold
relative to the baseline audiogram of an average of 10 dB(A) or more at
2000, 3000, and 4000 Hz in either ear; and
2. in determining whether a standard threshold shift has occurred, no
allowance shall be made for the contribution of aging (presbycusis).
(ix) audiometric test requirements:
1. audiometric tests shall be pure tone, air conduction, hearing threshold
examinations, with test frequencies including as a minimum 500, 1000,

ADOSH-SF – Codes of Practice - CoP 3.0 – Occupational Noise
Version 4.0 – 15 th July 2024 Page 10 of 24
2000, 3000, 4000, and 6000 Hz. Tests at each frequency shall be taken
separately for each ear;
2. audiometric tests shall be conducted with audiometers (including
microprocessor audiometers) that meet the specifications of, and are
maintained in accordance with,
American National Standards Institute
S3.6-2010 or
International Standards Organization (ISO) 8253-1:2010;
3. pulsed-tone and self-recording audiometers, if used, shall meet the
requirements specified in Section 3.5 of this CoP; and
4. audiometric examinations shall be administered in a room meeting the
requirements listed in Section 3.6 of this CoP.
(x) audiometric calibration:
1. the functional operation of the audiometer shall be checked before each
day’s use in accordance with manufacturer’s specifications. If no
specification exists, the audiometer shall be checked by testing a person
with known, stable hearing thresholds, and by listening to the
audiometer’s output to make sure that the output is free from distorted or
unwanted sounds. Deviations of 10 dB(A) or greater require an acoustic
calibration;
2. audiometric calibration shall be checked annually in accordance with
manufactures specifications. Test frequencies below 500 Hz and above
6000 Hz may be omitted from this check. Deviation of 15 dB(A) or greater
require an exhaustive calibration; and
3. an exhaustive calibration shall be performed at least every two years in
accordance with manufacturer’s specifications and
American National
Standards Institute S3.6-2010 or
International Standards Organization
(ISO) 8253-1:2010. Test frequencies below 500 Hz and above 6000 Hz
may be omitted from this check.
(xi) hearing protectors:
1. employers shall make hearing protectors available to all employees
exposed to an 8-hour time-weighted average of 85 dB(A) or greater at no
cost to employees. Hearing protectors shall be replaced as necessary;
2. employers shall require all employees exposed to an 8-hour time-
weighted average of 85 dB(A) or greater to wear hearing protection;
3. employees shall be given the opportunity to select their hearing
protectors for a variety of appropriate hearing protectors provided by the
employer;
4. employers shall provide training in the use and care of all hearing
protectors provided to employees; and
5. employers shall make sure that the hearing protectors provided to
employees shall fit the employee correctly and provide the required
protection.
(xii) hearing protector attenuation:
1. employers shall evaluate hearing protector attenuation for the specific
noise environments in which the protector shall be used. The employer

ADOSH-SF – Codes of Practice - CoP 3.0 – Occupational Noise
Version 4.0 – 15 th July 2024 Page 11 of 24
shall use one of the evaluation methods described in Section 3.8 of this
document;
2. hearing protectors shall attenuate employee exposure at least to an 8-hr
time-weighted average of 85 dB(A);
3. in the event hearing protectors cannot be purchased with an attenuation
rating that shall bring the exposure below an 8-hr time-weighted average
of 85 dB(A), double protection (both muffs and plugs) shall be worn.
Employers shall calculate the rating for the double hearing protection
using the requirements of Section 3.8(b) of this document. Double hearing
protectors shall attenuate employee exposure at least to an 8-hr time-
weighted average of 85 dB(A); and
4. the appropriateness of hearing protector attenuation shall be re-
evaluated whenever employee noise exposures increase to the extent
that the hearing protectors provided no longer provide appropriate
attenuation. The employer shall provide more effective hearing
protection where necessary.
3.4. Noise Hazard Signage
(a) Employers shall post warning signs in each work area where the noise levels are or
exceed 85 dB(A) notifying employees and visitors that hearing protection is required
if entering or working in the area. If double hearing protection is required, this shall
be identified on the warning sign.
(b) Signs shall be in the language of employees entering the area. Signs shall comply with
ADOSH-SF – CoP 17.0 – Safety Signage and Signals.
3.5. Audiometric Measuring Instruments
(a) In the event that pulse-tone audiometers are used, they shall have a tone on-time of
at least 200 milliseconds.
(b) Self-recording audiometers shall comply with the following requirements:
(i) the chart upon which the audiogram is traced shall have lines at positions
corresponding to all multiples of 10 dB(A) hearing level within the intensity
range spanned by the audiometer. The lines shall be equally spaced and shall be
separated by at least 1/4 inch. Additional increments are optional. The
audiogram pen tracings shall not exceed 2 dB(A) in width;
(ii) it should be possible to set the stylus manually at the 10 dB(A) increment lines
for calibration purposes;
(iii) the slewing rate for the audiometer attenuator shall not be more than 6
dB(A)/sec except that an initial slewing rate greater than 6 dB(A)/sec is
permitted at the beginning of each new test frequency, but only until the second
subject response;
(iv) the audiometer should remain at each required test frequency for 30 seconds
(+ or - 3 seconds). The audiogram shall be clearly marked at each change of
frequency and the actual frequency change of the audiometer shall not deviate

ADOSH-SF – Codes of Practice - CoP 3.0 – Occupational Noise
Version 4.0 – 15 th July 2024 Page 12 of 24
from the frequency boundaries marked on the audiogram by more than + or - 3
seconds; and
(v) it shall be possible at each test frequency to place a horizontal line segment
parallel to the time axis on the audiogram, such that the audiometric tracing
crosses the line segment at least six times at that test frequency. At each test
frequency the threshold shall be the average of the midpoints of the tracing
excursions.
3.6. Audiometric Test Rooms
(a) Rooms used for audiometric testing shall not have background sound pressure levels
exceeding those in Table 3.1 when measured by equipment conforming at least to the
Type 2 requirements
of American National Standard Specification for Sound Level
Meters, S1.4-1983 (R2006), and to the
Class II requirements of American National
Standard Specification for Octave-Band and Fractional-Octave-Band Analog and
Digital Filters, S1.11-2004 (R2009).
Octave-band center
frequency (Hz) 500 1000 2000 4000 8000
Sound pressure level (dB) 40 40 47 57 62
Table 3.1 – Maximum Allowable Octave-Band and Sound Pressure Levels for Audiometric
Test Rooms
3.7. Computation of Employee Noise Exposure
(a) The sound pressure level shall be determined by a sound level meter or dosimeter
conforming, as a minimum, to the requirement of
the American National Standards
Institute (ANSI) Specification for Sound Level Meters, S1.4-1983 (R2006), Type S2A,
or
ANSI S1.25-1991 (R2007) Specification for Personal Noise Dosimeters. The
measurement device shall be set to use the A-weighted network with slow meter
response. The duration of exposure shall not exceed that shown in Appendix 1. These
values apply to the total duration of exposure per working day regardless of whether
this is one continuous exposure or a number of short-termed exposures.
(b) A sound calibrator shall be used for direct calibration of sound level meter or dosimeter
before and after noise measurements. The sound calibrator shall comply with:
(i) EN/IEC 60942 (2003) Class LS and Class 1; and/or
(ii) ANSI S1.40-1984.
(c) Sound level meters and dosimeters shall be calibrated by the manufacturer or a
manufacturer approved third party organization according to manufacturer’s
specifications.
(d) Occupational noise exposure assessments shall be completed in accordance with this
CoP.
(e) When the daily noise exposure is composed of two or more periods of noise exposure
of different levels, their combined effect shall be considered rather than the individual
effect of each.

ADOSH-SF – Codes of Practice - CoP 3.0 – Occupational Noise
Version 4.0 – 15 th July 2024 Page 13 of 24
(f) When sound level meter or dosimeter readings equal or exceed 85 dB(A), employers
shall calculate the allowable noise using the calculation found in Appendix 3.
3.8. Computation of Hearing Protection Attenuation
(a) Calculating single hearing protection device (plugs or muffs):
(An example of how to perform this calculation can be found in Appendix4.)
(i) when calculating the hearing protection attenuation, the employer shall take
the noise reduction rating (NRR) stated by the manufacture of the hearing
protection and subtract 7dB(A) from the rating; and
(ii) the calculated hearing protection attenuation shall then be subtracted from the
worksite sound level measured with a sound level meter or dosimeter on the A-
weighted scale. If the calculated exposure is below 85 dB(A), the hearing
protection shall be determined to be appropriate.
(b) Calculating double hearing protection (plugs and muffs) - When a single hearing
protection device is not sufficient to protect an employee for a noise hazard, and
double protection (plugs and muffs) is required, the hearing protection attenuation
shall be calculated in the following manner:
(An example of how to perform this calculation can be found in Appendix 4.)
(i) calculate the hearing protection attenuation for the plugs as stated in Section
3.8(a);
(ii) calculate the hearing protection attenuation for the muffs by subtracting 25%
of the manufacture rated NRR. If the calculation gives you a decimal, round
down to nearest whole number;
(iii) add the calculated attenuation for the plugs and muffs together to get the total
attenuation; and
(iv) the calculated total hearing protection attenuation shall then be subtracted
from the worksite sound level measured with a sound level meter or dosimeter
on the A-weighted scale. If the calculated exposure is below 85 dB(A), the
double hearing protection shall be determined to be appropriate.

ADOSH-SF – Codes of Practice - CoP 3.0 – Occupational Noise
Version 4.0 – 15 th July 2024 Page 14 of 24
4. Record Keeping
(a) Exposure monitoring, medical surveillance, examination and consultation records shall
be kept for a minimum of period of employment plus 30 years, as per
ADOSH-SF –
Element 9 – Compliance and Management Review.
(b) All compliance and training records shall be kept for a minimum of five (5) years, as
per
ADOSH-SF – Element 9 – Compliance and Management Review.

ADOSH-SF – Codes of Practice - CoP 3.0 – Occupational Noise
Version 4.0 – 15 th July 2024 Page 15 of 24
5. References
•
2010 TLVs and BEIs – American Conference of Governmental Industrial Hygienists.
•
Health and Safety Executive, Statutory Instruments 2005 No.1643, Health and
Safety – The Control of Noise at Work Regulations 2005
•
U.S. Occupational Safety and Health Administration, 29 CFR 1910.95 – Occupational
Noise Exposure
•
American National Standards Institute (ANSI) Specification for Sound Level Meters,
S1.4-1983 (R2006), Type S2A
•
American National Standards Institute (ANSI) S1.25-1991 (R2007) Specification
for Personal Noise Dosimeters
•
NIOSH Publication No. 98-126, Criteria for a Recommended Standard: Occupational
Noise Exposure
•
American National Standards Institute (ANSI) - Measurement of Occupational Noise
Exposure, ANSI S12.12-1996 (ANSI 1991a)

ADOSH-SF – Codes of Practice - CoP 3.0 – Occupational Noise
Version 4.0 – 15 th July 2024 Page 16 of 24
6. Document Amendment Record
Version Revision Date Description of Amendment Page/s Affected
4.0
15 th July 2024
System acronym updated from OSHAD-SF
to ADOSH-SF to accurately reflect
document title
Throughout
Change from OSHAD to ADPHC
Change of Logo
Minor editorial changes throughout the
document without changing requirements.
Title of Mechanism 7.0 updated to ADOSH-
SF – Mechanism 7– Public and Preventive
Health Practitioner and Service Provider
Accreditation
OSHAD-SF - Mechanism 8.0 - OSH
Practitioner Registration deleted

ADOSH-SF – Codes of Practice - CoP 3.0 – Occupational Noise
Version 4.0 – 15 th July 2024 Page 17 of 24
APPENDIX 1: Allowable Duration of Exposure Based on Sound Level
dB(A)
ﻣﺴﺘﻮﻯ
ﺍﻟﺘﻌﺮﺽ ﺍﻟﻔﺘﺮﺓ ﺍﻟﺰﻣﻨﻴﺔ ﻣﺴﺘﻮﻯ
ﺍﻟﺘﻌﺮﺽ ﺍﻟﻔﺘﺮﺓ ﺍﻟﺰﻣﻨﻴﺔ
Exposure
Level, L Duration,
T Exposure
Level, L Duration,
T
(dBA) Hours Minutes Seconds (dBA) Hours Minutes Seconds
80 24 - - 106 - 3 45
81 20 10 - 107 - 2 59
82 16 - - 108 - 2 22
83 12 42 - 109 - 1 53
84 10 5 - 110 - 1 29
85 8 - - 111 - 1 11
86 6 21 - 112 - - 56
87 5 2 - 113 - - 45
88 4 - - 114 - - 35
89 3 10 - 115 - - 28
90 2 31 - 116 - - 22
91 2 - - 117 - - 18
92 1 35 - 118 - - 14
93 1 16 - 119 - - 11
94 1 - - 120 - - 9
95 - 47 37 121 - - 7
96 - 37 48 122 - - 6
97 - 30 - 123 - - 4
98 - 23 49 124 - - 3
99 - 18 59 125 - - 3
100 - 15 - 126 - - 2
101 - 11 54 127 - - 1
102 - 9 27 128 - - 1
103 - 7 30 129 - - 1
104 - 5 57 130-140 - - <1
105 - 4 43 - - - -
A person shall not be exposed to any continuous, intermittent, or impact noise levels above 100 dB(A), unless
the appropriate hearing protection is provided.

ADOSH-SF – Codes of Practice - CoP 3.0 – Occupational Noise
Version 4.0 – 15 th July 2024 Page 18 of 24
APPENDIX 2: Calculating dB(A) Using Octave Band Analysis Data
When noise levels are determined by octave band analysis, the equivalent A-weighted sound
level may be determined using the following procedure:
Step 1: The A-weighting corrections given in Table A shall be added or subtracted
arithmetically to each octave band sound pressure level;
Step 2: The A-corrected band levels shall be converted into arbitrary intensity units “I” using
Table B;
Step 3: The values of “I” shall be added together arithmetically;
Step 4: The total value of “I” shall be converted into A-weighted sound level, dB(A), using
Table B. When the total value of “I” falls between two values in the table, take the
next higher value of sound level.
Octave band center
frequency Hz 63 125 250 200 1000 2000 4000 8000
A-weighting correction dB -26 -16 -9 -3 0 +1 +1 -1
Table A
dB 0 1 2 3 4 5 6 7 8 9
60 .0010 .0013 .0016 .0020 .0025 .0032 .0040 .0050 .0063 .0079
70 .010 .013 .016 .020 .025 .032 .040 .050 .063 .079
80 .100 .126 .158 .200 .251 .316 .398 .501 .631 .794
90 1.00 1.26 1.58 2.00 2.51 3.16 3.98 5.01 6.31 7.94
100 10.0 12.6 15.8 20.0 25.1 31.6 39.8 50.1 63.1 79.4
110 100 126 158 200 251 316 398 501 631 794
Table B
Example Problem:
The first two columns in the table below show the octave band sound pressure level measured
in each octave band center frequency. Column three shows the A-weighting corrections taken
from Table A as required in Step1 above, and column four gives the A-corrected octave band.
The A-corrected octave band levels are converted into “I” values using Table B as required in
Step 2 above. Column 5 shows the “I” value for each frequency, which is then added together
as required in Step 3 above. The total value for “I” is then converted into an A-weighted sound
level value using Table B, as required in Step 4 above.

ADOSH-SF – Codes of Practice - CoP 3.0 – Occupational Noise
Version 4.0 – 15 th July 2024 Page 19 of 24
1 2 3 4 5
Octave band
center
frequency
HZ
Octave band
sound pressure
level
dB
A-weighting
correction from
Table A
dB
A-corrected
octave band
level
dB
“I” value from
Table B
125 95 -16 79 0.079
250 102 -9 93 2.000
500 105 -3 102 15.800
1000 102 0 102 15.800
2000 98 +1 99 7.940
4000 89 +1 90 1.000
8000 79 -1 78 0.063
• Total value of “I” = 42.682
• From Table B the nearest A-weighted sound level to the nearest decibel, as required by
Step 4 above = 107 dB(A)

ADOSH-SF – Codes of Practice - CoP 3.0 – Occupational Noise
Version 4.0 – 15 th July 2024 Page 20 of 24
APPENDIX 3: Calculation of Allowable Noise:
T = reference duration corresponding to the measured sound level
L = sound level measured in decibels (A-weighted sound level)
T =
8
2 (L-85)/3
Example:
You measure a sound level of 94dB(A), what is the length of exposure allowed before 8-hr
time-weighted average of 85 dB(A)?
T =
8
T = 1 hr 2 (94-
85)/3
You are allowed one hour of exposure before you shall exceed the 8-hr time-weighted average
of 85 dB(A).
Note: This is the same as found in Appendix 1.
Calculation of total noise exposure (dose) shall be done using the following calculation:
D = noise dose (less than 1 = no overexposure and greater than 1 = overexposure)
C = total time of exposure at a specific noise level
T = reference duration corresponding to the measured sound level
** see above calculation or Appendix 1.
D = C1
+
C2
+
Cn
T1 T2 Tn
Example:
You measure a sound level of 88dB(A) for 2 hours, 91dBA for 30 min, and 85dB(A) for 3 hours.
Have you exceeded the allowed 8-hr time-weighted average of 85 dB(A)?
T88 = 4hrs, T91 = 2hrs, T85 = 8hrs
C88 = 2hrs, C91 = 0.5hrs, C85 = 3hrs
D = 2 +
0.5
+
3 D
=1.125 4 2 8
Since D is greater than one (1.125) you have exceeded the 8-hr time-weighted average of 85
dB(A).

ADOSH-SF – Codes of Practice - CoP 3.0 – Occupational Noise
Version 4.0 – 15 th July 2024 Page 21 of 24
APPENDIX 4: Computation of Hearing Protection Attenuation
Calculating Single Hearing Protection Device (Plugs or Muffs):
(i) When calculating the hearing protection attenuation, the employer shall take the noise
reduction rating (NRR) stated by the manufacturer of the hearing protection and subtract
7dB from the rating.
(ii) The calculated hearing protection attenuation shall then be subtracted from the worksite
sound level measured with a sound level meter or dosimeter on the A-weighted scale. If the
calculated exposure is below 85 dB(A), the hearing protection shall be determined to be
appropriate.
Example:
• Noise monitoring determines a level of 94 decibels on the A-weighted scale.
• Hearing protection is rated by the manufacture to have a NRR of 28dB
• Hearing Protection Attenuation = 28dB – 7dB = 21dB
• Employee exposure with hearing protection = 94dB(A) – 21(NRR) = 73dB(A)
• The hearing protection is appropriate to protect employees.
Calculating double hearing protection (plugs and muffs):
When a single hearing protection device is not sufficient to protect an employee for a noise
hazard, and double protection (plugs and muffs) is required, the hearing protection attenuation
shall be calculated in the following manner:
(i) Calculate the hearing protection attenuation for the plugs as stated above for single
hearing protection device.
(ii) Calculate the hearing protection attenuation for the muffs by subtracting 25% of the
manufacture rated NRR. If the calculation give you a decimal, round down to nearest
whole number.
(iii) Add the calculated attenuation for the plugs and muffs together to get the total
attenuation
(iv) The calculated total hearing protection attenuation shall then be subtracted from the
worksite sound level measured with a sound level meter or dosimeter on the A-weighted
scale. If the calculated exposure is below 85 dB(A), the double hearing protection shall
be determined to be appropriate.
Example:
• Noise monitoring determines a level of 125 decibels on the A-weighted scale.
• Hearing protection for plugs is rated by the manufacture to have a NRR of 34dB
• Hearing protection attenuation for plugs = 34dB – 7dB = 27dB
• Hearing protection for muffs is rated by the manufacture to have a NRR of 25dB.
• Hearing protection attenuation for muffs:
o 25% of 25dB = 6.25dB
o Attenuation for muffs = 25dB – 6.25B = 18.75dB (round 18.75 dB down to 18dB)

ADOSH-SF – Codes of Practice - CoP 3.0 – Occupational Noise
Version 4.0 – 15 th July 2024 Page 22 of 24
• Attenuation for double hearing protection = 27dB + 18dB = 45dB
• Employee exposure with double hearing protection = 125db(A) – 45(NRR) = 80dB(A)
• The double hearing protection is appropriate to protect employees.

ADOSH-SF – Codes of Practice - CoP 3.0 – Occupational Noise
Version 4.0 – 15 th July 2024 Page 23 of 24