U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES

Public Health Service

Centers for Disease Control and Prevention

National Institute for Occupational Safety and Health CENTERS FOR DISEASE CONTROL

APE

D

AND PREVENTION

TR MENT OF HEALTH & HUMAN SERV

I

CES

•

USA
National Institute for Occupational Safety and Health

Foreword

The National Institute for Occupational Safety and Health’s (NIOSH) Health Hazard Evaluation and Technical

Assistance (HETA) program responds to approximately 400 requests per year from employers, employees, employee

representatives, other Federal agencies, and State and local agencies to examine suspected hazards in the workplace.

The typical HETA response to a request for assistance results in an evaluation of whether chemical, physical, biological,

or other agents are hazardous as used or found in the workplace followed by the development of recommendations for

control procedures, improved work practices, and medical programs to reduce exposure levels and prevent adverse

health effects. The results of individual evaluations may trigger wider studies of similar exposures in other settings, or

may stimulate recommendations for implementation or modification of health standards. Requests received by the

HETA program tend to reflect emerging occupational problems. More than 8,000 evaluations have been completed

since the inception of the HETA program in 1972 on hazards such as chemical exposures, indoor air quality, ergonomics

and noise-induced hearing loss.

Noise-induced hearing loss is one of the most prevalent occupational health hazards facing American workers today.

Approximately 30 million people are exposed to hazardous levels of noise at their work sites and an additional 9 million

are at risk from other substances such as solvents and metals. While noise-induced hearing loss is irreversible, it is

preventable and its risk can be reduced with the application of noise controls and occupational hearing loss prevention

programs.

When evaluating noise during an Health Hazard Evaluation (HHE), staff may monitor noise exposures, survey worker

medical information, conduct worker audiometric evaluations, assess worker use of hearing loss protection devices, and

evaluate hearing loss prevention policies and standards. NIOSH researchers present written reports detailing the results

of their evaluations to help companies assess workers exposure to noise, evaluate and plan noise controls, and develop

employee education programs on hearing loss prevention.

This document presents summaries of the HHEs related to noise conducted from 1986-1997. The summaries are

organized by industry. In several cases noise exposure was just one of many exposures that NIOSH researchers

investigated at the work site.

The full reports listed in this document are available from the Hazard Evaluation and Technical Assistance Branch.

Contact:

The Hazard Evaluation and Technical Assistance Branch (HETAB)

Alice Hamilton Laboratory

4676 Columbia Parkway

Cincinnati, OH 45226

or call:

1-800-35-NIOSH

More information about the Health Hazard Evaluation Program is available on the web at

http://www.cdc.gov/niosh/hhe.html.
National Institute for Occupational Safety and Health 3

Agriculture, Forestry, and

Fishing (SIC 0100-0999)

Assessing Exposure to Noise during

Aerial Pesticide Application

HETA 95-0248-2562

March 1996

Purpose: To investigate worker exposure to noise during

aerial pesticide application.

Keywords: SIC 0721 (Crop Planting, Cultivating, and

protecting) aerial dusting and spraying, pesticide

exposure, organophosphate, carbamate, pyrethroid,

skin exposure, mixer-loader, pilot, noise, personal

hearing protection, hearing conservation program,

heat stress.

Abstract: NIOSH researchers conducted a HHE at an

aerial pesticide application firm in Arkansas.

Personal noise monitoring was conducted on two

pilots and all three mixer-loaders and spectral noise

analyses were conducted to determine the dominant

noise frequencies and to evaluate the flight helmets

for noise attenuation. The noise monitoring showed

that both pilots sampled were exposed TWA sound

levels higher than the NIOSH REL and the OSHA

PEL for noise. The TWA noise exposures of the

mixer loaders also exceeded the NIOSH REL, but not

the OSHA regulation. Recommendations are made

for improving safety during the use of pesticides and

for the implementation of a medical surveillance

program.

Construction (SIC 1500-1799)

Assessing Workers’ Exposure to Noise

in Bridge Repainting

HETA 91-006-2193

March 1992

Purpose: To investigate exposure to noise in bridge repainting.

Keywords: SIC 1622 (Bridge, Tunnel, and Elevated

Highway Construction), lead, abrasive blasting,

construction, bridge workers.

Abstract: NIOSH conducted a Health Hazard Evaluation

(HHE) to evaluate workers’ exposure to noise during

repainting of the Brent Spence Bridge, a double-level

highway bridge over the Ohio River in Covington,

Kentucky. Personal exposures to noise, expressed as

8-hour time-weighted averages (TWAs), ranged from

89.6 decibels on the Aweighted slow weighting

network [dB(A)] to 105.4 dB(A). Most workers

surveyed had 8-hr TWA noise exposures exceeding

the NIOSH Recommended Exposure Limit (REL) of

85 dB(A), and the Occupational Safety and Health

Administration (OSHA) permissible exposure limit

(PEL) of 90 dB(A). All workers were provided, and

used, hearing protection devices (earplugs); however,

they were not protected by a comprehensive hearing

conservation program. Recommendations for an

improved hearing conservation program are

presented in the full report.

Manufacturing (SIC 2000-3999)

Evaluation of Planned Noise Abatement

Procedures in Two Sawmill Facilities

HETA 88-030-2109

April 1991

Purpose: To investigate planned noise abatement

procedures in two sawmill facilities.

Keywords: SIC 2421 (Sawmills and Planing Mills,

General), noise exposure, hearing loss, noise control

engineering, hearing conservation programs.

Abstract: In this evaluation, NIOSH assisted a sawmill

company in evaluating the effects of noise abatement

procedures planned for its two milling facilities.

Additionally, employee data were gathered on

hearing ability, employment history at the company,

and any noise exposure or medical problems that

might affect hearing. Results revealed that 73% of

the surveyed job descriptions in the mills had average

noise levels in excess of the NIOSH REL. The noise

controls tested in the mill were found to produce

varying amounts of noise reduction to the workers.

The hearing tests revealed that 72.5% of the

employees exhibited some degree of hearing

impairment at one or more audiometric test

frequency. NIOSH investigators concluded that a

health hazard exists for the companys employees. It

was recommended that a comprehensive hearing

conservation program minimally complying with

OSHA regulations should be implemented in order to

protect these employees from excessive noise

exposures in the work place.
4 National Institute for Occupational Safety and Health

Evaluating Noise Controls at a Paper Mill

Facility

HETA 86-437-1818

July 1987

Purpose: To investigate the effectiveness of a rotary

knife blade enclosure in reducing worker exposure to

noise at a paper mill facility.

Keywords: SIC 2645 (DieCut Paper and Paperboard and

Cardboard), noise, paper making industry, paper

cutters, enclosures.

Abstract: NIOSH conducted an evaluation of the noise

levels found in the small paper cutter area of an Ohio

paper mill before and after installing an enclosure

over the rotary knife blade. The results of the area

noise sampling showed a noise reduction of 13 dB(A)

as a function of the knife blade enclosure, going from

108 dB(A) prior to installation to 95 dB(A) after

enclosing the blade. However, the personal noise

dosimetry results showed little change from the

preenclosure to postenclosure sampling period. This

apparent paradox was partially explained as the result

of different operators and their work practices or

different weights of paper. It does, however, point

out the difference between noise exposures to

workers and noise levels being emitted by machinery.

A noise hazard was found to exist in the small cutter

area of the paper mill. The potential for excess noise

exposure was reduced by enclosing the rotary knife

blade, however eighthour TWA values in excess of 85

dB(A) were common in the area even after the blade

was enclosed. Recommendations to further reduce

the noise hazard and to protect the workers’ hearing

are provided in the full report.

Noise Exposures at a Specialty

Chemical Plant

HETA 86-071-1817

July 1987

Purpose: To investigate worker exposure to noise at a

specialty chemical manufacturing plant.

Keywords: SIC 2842 (Specialty Cleaning, Polishing, and

Sanitation Preparations) batch process, methylene

chloride, noise, acids, alkaline dust, ventilation,

personal protective equipment.

Abstract: NIOSH conducted a HHE to determine worker

exposure to noise at a specialty chemical

manufacturing plant. Fullshift noise exposures

ranged from 78 to 88 dB(A) TWA with a mean of 82

dB(A) TWA. The percent of the daily allowable

noise exposure based on the OSHA noise PEL of 90

dB(A) for eight hours ranged from 19 to 74%. Five

workers had fullshift noise exposures at or above 85

dB(A) TWA, the NIOSH recommended exposure

limit. Maximum one minute average noise levels

encountered by workers during the shift ranged from

88 to 113 dB(A). Overall area noise measurements

ranged from 84 to 96 dB(A). Noise levels in the

facility represent a risk for potential hearing

impairment. Some areas and equipment generate

sufficiently high noise levels (85 dB(A) or greater) to

present an auditory hazard for unprotected workers in

the immediate area. Recommendations addressing a

hearing conservation program are presented in the

full report.

Evaluating Noise at a Pipe Fabricating

Plant

HETA 88-214-1952

March 1989

Purpose: To investigate noise exposure at a pipe

fabricating plant.

Keywords: SIC 3079 (Pipe Fabrication), extruding,

polyvinyl chloride, polyethylene, polystyrene, noise.

Abstract: NIOSH researchers investigated exposures to

hazardous levels of noise at a pipe fabricating plant in

West Virginia. Personal, TWA noise exposure

measurements taken over a three-day period ranged

from 80 dB(A) to 104 dB(A). Job categories

working in areas with hazardous noise levels

included grinder, line takeoff attendant, and hopper

attendant. Workers in the grinding area used hearing

protection; however, workers in the other areas did

not use hearing protection and some were exposed to

hazardous noise levels. On the basis of data obtained

during this evaluation, NIOSH investigators

concluded that some workers receive hazardous noise

exposures. Recommendations to correct these

occupational health/safety problems are presented in

the full report.
National Institute for Occupational Safety and Health 5

Evaluation of Noise Exposures at a

Glass Products Manufacturing

Facility

HETA 89-137-2005

January 1990

Purpose: To investigate worker exposure to noise in a

glass products manufacturing facility.

Keywords: SIC 3231 (Glass Products, Made of

Purchased Glass), silica, hydrofluoric acid, sulfuric

acid, organic vapors, mineral spirits, pine oil, noise,

cumulative trauma disorder, ventilation.

Abstract: NIOSH conducted an evaluation of employee

exposures to noise in a glass manufacturing facility

along with many other occupational exposures.

Noise exposures were assessed by measuring the

sound levels in the Furnace, Decorating, and

Mirroring Departments. Personal noise exposures

ranged from 79 to 92 dB(A), TWA, in the areas

tested. Noise levels in excess of the NIOSH REL

were found in several departments. Based on the

data collected during this evaluation, NIOSH

investigators concluded that employees in several

departments at the company were exposed to

excessive levels of noise. Recommendations for

implementing hearing conservation programs are

included in the full report.

Noise Exposures and Hearing Loss in

Workers Involved in the Manufacture

of Roofing Granules

HETA 91-0091-2418

May 1994

Purpose: To investigate noise exposures and hearing loss

in roofing granules manufacturing.

Keywords: SIC 3295 (Minerals and Earths, Ground or

Otherwise Treated), silica, noise, hearing

conservation.

Abstract: This investigation was performed in response

to a request from the Oil, Chemical and Atomic

Workers’ union that listed hearing loss as a health

concern in workers involved in the manufacture of

roofing granules. Hearing losses were reportedly

documented by company hearing tests, but the union

reported that the manufacturer did not address the

losses. NIOSH investigators performed a walkthrough inspection of the plant. Medical records

from both individual employees and the company

medical department, and health survey questionnaires

distributed by the local union were reviewed. Noise

dosimeter measurements and area noise levels were

made in several areas of the plant. Personal noise

dosimetry revealed that a majority of the samples

were in excess of the NIOSH REL of 85dB(A) for an

8-hour TWA. Recommendations for reducing

exposures to noise are included in full report.

Field Survey at an Oxygen Process Shop

to Evaluate Potential Hazards from

Air Contaminants, Noise, Heat Stress,

and Ergonomic Problems

HETA 92-0230-2471

November 1994

Purpose: To investigate noise exposures in oxygen

processing.

Keywords: SIC 3312 (Steel Works, Blast Furnaces

[including coke ovens], and Rolling Mills), air

contaminants, metals, sulfur dioxide, noise, hearing

aids, heat stress, ergonomics, vibration, lifting.

Abstract: NIOSH investigators conducted a field survey

at an oxygen process shop to evaluate potential

hazards from noise. Employee reports of tinnitus

(ringing in the ears) related to work schedules and

long-term hearing problems suggest that the

companys hearing conservation program might not

be effective. The interviewed employees identified

the following sources of noise: warning sirens and

horns, scrap dropping into the charge, plates hitting

the floor, furnaces, mixers, discharge of the electric

arc, preheaters, heavy equipment such as grade-alls

and cranes, air hammers, and poorly functioning airconditioning units. The maximum area noise

measurements ranged from 80 to 106 dB(A),

depending on the area. The findings of this health

hazard evaluation indicate that the shop employees

are potentially exposed to dangerous levels of noise,

which may be having a deleterious effect on

employee hearing. Specific recommendations for

reducing employee exposure to noise are made in the

full report.
6 National Institute for Occupational Safety and Health

Evaluating Noise Exposures Occurring

in the Manufacture of Road Signs

HETA 86-191-1836

February 1987

Purpose: To investigate noise levels in a sign

manufacturing shop.

Keywords: SIC 3499 (Fabricated Metal Products, Not

Elsewhere Classified) silk-screening, organic

solvents, inks, noise, sign fabrication.

Abstract: NIOSH investigators evaluated noise

exposures from the sign fabrication process

conducted at a sign shop in West Virginia. Personal

noise exposure measurements were taken using a

noise dosimeter and a portable sound level meter

with an octave band analyzer. Personal, TWA noise

exposures from the sign fabrication shop did not

exceed allowable exposure levels as averaged over

the entire work shift. However, some workers

received brief exposures to sound levels above 115

dB(A) from the operation of the metal saw. NIOSH

investigators concluded that some workers receive

potentially hazardous noise exposures in the sign

fabrication shop. Recommendations for prevention

of these problems are presented in the full report.

Evaluating Noise Levels at an Outboard

Motor Manufacturing Facility

HETA 93-0498-2409

March 1994

Purpose: To investigate noise in outboard motor

manufacturing.

Keywords: SIC 3519 (Internal Combustion Engines, Not

Elsewhere Classified), outboard marine motor

manufacturing, noise dosimetry, octave-band

analysis, hearing conservation, engineering controls.

Abstract: Investigators from NIOSH conducted a HHE

to evaluate noise levels at an outboard motor

manufacturing facility. A request from the joint

union/management team at the company asked for

assistance from NIOSH to help meet a company

noise reduction goal of 82 dB(A). The team felt that

a reduction in plant noise would improve workers’

ability to communicate, reduce stress in the work

place, and improve product quality while protecting

workers from occupational hearing loss. Personal

noise exposure measurements collected with noise

dosimeters on eighteen employees and octave band

analyses of various departments were completed over

two days at the facility. Prominent noise sources

included the use of compressed air in several

operations and outboard motor noise generated

during the wet and dyno testing operations. The

results of the evaluation revealed that employees in

the machining, assembly, and testing departments

were exposed to potentially harmful noise. A

majority of the TWA noise exposure levels exceed the

NIOSH REL for occupational noise.

Recommendations for implementing specific

elements of a hearing conservation program as well

as suggestions for noise controls that should help to

reduce the noise levels in the facility were offered in

the full report.

Evaluating Worker Exposure to Noise at

a Manufacturer of Industrial

Centrifugal Equipment

HETA 95-0167-2539

November 1995

Purpose: To investigate exposure to noise in industrial

centrifugal manufacturing.

Keywords: SIC 3559 (Special industry machinery, not

elsewhere classified), industrial centrifugal

equipment manufacture, noise exposure, noise

dosimetry, hearing conservation.

Abstract: NIOSH received a request from employees

and from a United Auto Workers local at a

manufacturer of industrial centrifugal equipment to

conduct a health hazard evaluation at the facility.

The concern was worker noise exposure in the main

building, particularly the noise associated with a

recently installed air compressor. In the request, it

was pointed out that a few employees had been

identified as having hearing loss at a local hospital.

The employees were concerned that the losses may

be occupationally related. A NIOSH investigator

conducted a full-shift noise survey in the main

building of the facility using noise dosimeters.

Additional noise measurements were made with a

real-time analyzer to determine the spectral content

of specific noisy operations. Based on the results of

the noise data analyses and observations made during

the evaluation, the NIOSH investigator concluded

that a health hazard related to potential hearing loss

exists for employees at facility. A majority of the

workers were exposed to time-weighted noise levels

in excess of the NIOSH recommendation, while 35%
National Institute for Occupational Safety and Health 7

of the sampled employees exceeded the OSHA action

level that stipulates that a hearing conservation

program needs to be implemented. Hearing

conservation program recommendations toward

reducing the noise exposures and preventing further

hearing losses were offered in the report.

Evaluating Employees’ Noise Exposures in

Conjunction with the Use of Personal

Radio Headsets on the Job Site

HETA 90-281-2319

May 1993

Purpose: To investigate noise exposures and personal

radio headset usage in an electrical distribution

equipment manufacturing facility.

Keywords: SIC 3613 (Electric Transmission and

Distribution Equipment, Switchgear and Switchboard

Apparatus), noise, personal radio headsets, hearing

conservation programs.

Abstract: NIOSH received a request for a HHE to

evaluate employees’ occupational noise exposures in

conjunction with the use of personal radio headsets

on the job site. One portion of the request concerned

the applicability of employees using a radio headset

over plugged ears in areas requiring hearing

protection. Employee noise exposures measured with

noise dosimeters revealed a median 8 hour TWA

noise exposure of 84.6 dB(A). One full-shift noise

sample exceeded 90 dB(A), the OSHA PEL.

Because 50% of the noise exposures equaled or

exceeded the recommended limits, investigators

determined that a potential for employee exposure to

excessive noise exists. The company should continue

with its hearing conservation program that was in

place at the time of the survey. Also, the potential for

excessive noise produced by personal radio headsets

turned to full volume should lead the company to

educate the employees on the hazards associated with

the devices. Specific recommendations are contained

in the full report.

Evaluation of Potential Exposures to

Noise at an Energy and Automation

Plant

HETA 91-305-2267

November 1992

Purpose: To investigate noise exposures in an energy

automation plant.

Keywords: SIC 3621 (Motors and Generators), motor

manufacturing, trace metals, noise, welding, brazing,

soldering.

Abstract: A HHE was conducted to evaluate potential

exposures to noise at an energy and automation plant.

Employee interviews and an area noise survey were

conducted. The survey identified several areas of the

plant where workers may have been overexposed to

noise. A full-shift noise survey was conducted to

document employees personal noise exposures in the

welding, punch press, and machine taping areas.

Results of the environmental monitoring indicate that

a health hazard existed for welders and press

operators from overexposures to noise.

Recommendations were provided to reduce noise

exposures and improve the hazard communication

program.

Evaluating Noise Exposure in an

Electronics Manufacturing Plant

HETA 91-021-2144

October 1991

Purpose: To investigate noise exposure in an electronic

manufacturing plant.

Keywords: SIC 3651 (Household Audio and Video

Equipment), noise exposure, noise control

engineering, hearing conservation programs.

Abstract: At the request of company management,

NIOSH conducted a HHE at an electronics

manufacturing plant to assist the company in

determining the spectral characteristics of worker

noise exposures for the purpose of the reduction of

these levels by the company’s plant engineering

department. Area noise sampling and worker noise

dosimeter measurements were made in several

locations of the facility to determine workers noise

exposures during their work shifts. The results of the

noise measurements revealed several areas in the

plant where the workers are exposed to noise levels

in excess of 85 dB(A), but not in excess of 90 dB(A).

Because several of the area noise measurements and

the worker’s personal noise dosimetry values were in

excess of the NIOSH Recommended Exposure Limit

of 85 dB(A), NIOSH investigators conclude that a

potential health hazard exists for the employees.

However, because no employee audiometric records

were evaluated in this evaluation, it cannot be

determined if these noise levels have had a

deleterious effect on the workers’ hearing. It was

recommended that the company use the spectral
8 National Institute for Occupational Safety and Health

noise data to devise noise reduction controls in the

affected departments. Specific recommendations

were given for the implementation of a

comprehensive hearing conservation program that

should be activated until the noise exposures can be

permanently reduced to levels below 85 dB(A).

Evaluating Worker Exposure to Noise at

a Plastic Accessories Manufacturing

Plant

HETA 87-159-1962

April 1989

Purpose: To investigate worker exposure to noise at a

plastic accessories manufacturing plant.

Keywords: SIC 3751 (Motorcycles), acetone, styrene,

noise.

Abstract: NIOSH conducted an evaluation of workers

noise exposures at a plastic accessories

manufacturing plant. Nine employees wore personal

noise dosimeters to assess their noise exposures. A

total of twothirds of the full shift noise exposures

were in excess of the NIOSH REL for noise and the

OSHA action level for implementation of a hearing

conservation program. Because of this finding,

attempts to implement engineering controls in some

of the noisier operations should be investigated.

Measures to reduce noise exposures and improve

workers safety and health are recommended in the

full report.

Transportation and Public

Utilities (SIC 4000-4971)

Determining Noise Exposure of Postal

Employees

HETA 92-056-2223

May 1992

Purpose: To investigate noise exposure from an

automated Small Parcel and Bundle Sorter.

Keywords: SIC 4311 (United States Postal Service),

noise, automated sorting machines, letter carriers.

Abstract: In response to postal employee concerns, an

investigator from NIOSH conducted noise surveys at

a local post office station to document noise

exposures experienced by employees in the letter

sorting area which also houses an automated Small

Parcel and Bundle Sorter (SPABS). Personal noise

dosimetry was conducted on letter carriers in the

sorting area and on postal clerks and mail handlers

servicing the SPABS. Although no noise levels were

measured that exceed current evaluation criteria for

noise exposure and occupational hearing loss, the

letter carriers do perceive that the noise emitted by

the SPABS is stressful and interferes with their work.

The noise from the automated sorting machine

measured by the NIOSH investigator is clearly

audible above the ambient noise in the letter sorting

area, with the stop/start warning device being much

louder than background noises. The type of noise

emitted by the warning device, measured in the

evaluation, meets several researchers’ definition of

noise as an occupational stressor because of its

unpredictability and lack of controllability.

Therefore, recommendations are made to reduce the

noise in the SPABS and letter sorting areas.

However, there are no current evaluation criteria to

cite specific noise levels that must be reached in

order to eliminate the non-auditory effects of the

noise exposure.

Evaluating Landfill Employee Exposure

to Noise

HETA 93-0696-2395

March 1994

Purpose: To investigate noise exposure in landfills.

Keywords: SIC 4953 (Refuse Systems), landfill, silica,

chromium, asbestos, noise, rubbish collection.

Abstract: In February 1993, NIOSH conducted a HHE

at an Ohio landfill facility to determine if employee

exposures to noise represented a health hazard.

Employees were using hearing protection devices to

guard against the hazards of occupational noise

exposure. Noise dosimetry was conducted over two

days on three heavy equipment operators, three

mechanics, and a laborer. The results of noise

dosimetry indicate that exposure to noise exceeded

the PEL of 90 dB(A) for an 8 hour TWA.

Recommendations are included in this report to

develop a comprehensive hearing conservation

program and gives suggestions for engineering

controls to reduce worker exposure to noise.
National Institute for Occupational Safety and Health 9

Evaluation of Noise Levels at a

Hydroelectric Power Plant

HETA 92-0243-2377

January 1994

Purpose: To investigate noise exposures in a

hydroelectric power plant.

Keywords: SIC 4910 (Electric services), noise,

audiometric testing, infrasound, hydroelectric power.

Abstract: NIOSH investigators conducted a HHE at an

Arkansas hydroelectric power plant in response to

employees’ concerns about excessive noise levels in

the power plant resulting from the generation of

electricity. Personal noise exposure measurements

were made on all of the electricians and mechanics at

work on the days of the surveys with noise

dosimeters set to measure noise according to

Department of the Army noise regulations. Spot

measurements of infrasound (sound below the sonic

range of human hearing) and simple measurements of

structural vibration were also made during the first

site visit. All of the mechanics and electricians who

worked in the power plant had noise exposures that

exceeded the U.S. Army Corps of Engineers safety

and health requirements. However, worker

compliance with the wearing of hearing protective

devices while working was observed to be good.

Deficiencies were discovered in the audiometric

testing program used at the power plant upon review

of their records.

Wholesale trade (SIC 5000-5199)

Potentially Hazardous Noise in a

Cosmetics and Drug Distribution

Warehouse

HETA 91-194-2153

October 1991

Purpose: To investigate noise exposure in a cosmetics

and drug distribution warehouse.

Keywords: SIC 5122 (Drug Proprietaries, Drug

Sundries), noise, warehousing.

Abstract: An investigation was conducted at a drug and

cosmetics distribution warehouse to evaluate

potentially hazardous noise in the workplace. During

the investigation, personal noise dosimetry was

performed, along with octave band area noise

measurements at various locations throughout the

facility. Analysis of the results of the personal and

area noise measurements indicated that the measured

values in the shipping area of the facility approach

the NIOSH REL and OSHA action level (AL) of 85

dB(A) for an 8-hour TWA. These noise results reveal

that no noise hazard exists at the drug company.

However, noise levels in the shipping area are only

slightly below the NIOSH REL and OSHA AL.

Therefore, recommendations are made to further

reduce employee exposures to noise using

engineering and administrative controls.

Services (SIC 7000-8999)

Evaluating Noise Exposure in a

Biomedical Laboratory

HETA 91-287-2228

June 1992

Purpose: To investigate noise exposure in a biomedical

lab.

Keywords: SIC 8734 (Testing Laboratories), biosafety,

agricultural, microbiological and biomedical

laboratories, noise.

Abstract: This HHE was performed in response to a

confidential employee request concerning

microbiological safety in a biomedical laboratory. In

addition, once the HHE was in progress, lab

management requested an evaluation of noise

exposures in the necropsy suite, in the electron

microscopy lab, and in a veterinarian’s office.

NIOSH investigators administered a questionnaire to

employees, performed industrial hygiene

measurements during the operation of laboratory

apparatus, evaluated selected laboratory hoods with a

thermo anemometer and smoke tubes, and measured

noise in the specified areas. The results showed that

the noise levels in these areas did not approach those

associated with the development of noise-induced

hearing loss. Recommendations are made for further

reducing the amount of noise to which workers are

exposed.
10 National Institute for Occupational Safety and Health

Public Administration

(SIC 9000-9721)

Evaluating Risk of Noise Induced

Hearing Loss for Fire Fighters in a

Metropolitan Area

HETA 88-0290-2460

September 1994

Purpose: To investigate noise exposure in fire fighters.

Keywords: SIC 9224 (Fire Departments, including

volunteer), noise exposure, noise dosimetry, fire

apparatus, hearing loss, hearing conservation.

Abstract: A HHE was conducted to evaluate noise

exposure levels and hearing loss for fire fighters in a

metropolitan area. Full-shift personal noise

measurements and audiometric testing of fire fighters

were done in the department. The noise dosimeter

surveys revealed that average noise exposures were

generally less than the NIOSH recommended

exposure limits, but there were brief occurrences of

noise levels greatly exceeding the exposure limits.

These high exposures were usually associated with

emergency response runs in the fire vehicles. A

statistically significant relationship was found

between length of time spent as a fire fighter and

hearing loss. Based on the results of the audiometric

data analyses, the NIOSH investigator concluded that

a health hazard exists for fire fighters and

recommended steps to the fire department to reduce

the noise exposures to the fire fighters and help

prevent further hearing losses.

Evaluating Risk of Noise Induced

Hearing Loss for Fire Fighters

HETA 89-0026-2495

March 1995

Purpose: To investigate noise exposure and hearing loss

in fire fighters.

Keywords: SIC 9224 (Fire Departments, including

volunteer), noise exposure, noise dosimetry, fire

apparatus, hearing loss, hearing conservation.

Abstract: A health hazard evaluation was completed by

testing noise exposure levels emitted by fire

emergency vehicles, noise exposure at fire stations,

and hearing loss for fire fighters. The noise surveys

revealed that while the 24-hour cumulative noise

doses were generally less than the NIOSH

recommended exposure limits, there were brief

occurrences of noise levels greatly exceeding the

exposure limits. These high exposures were usually

associated with emergency response runs in the fire

vehicles. The audiometric data showed a decline in

hearing ability in the high frequency sound region,

while at the same time, a significant “improvement”

in hearing at the low audiometric test frequencies was

discovered. These data suggest that, in spite of the

fire fighters’ improved ability to take a hearing test,

there was still a significant loss of hearing in the

noise sensitive region. Based on the results of the

audiometric data analyses, the NIOSH investigator

concluded that a health hazard exists for fire fighters

and recommended steps to the department to reduce

the noise exposures to the fire fighters and help

prevent further hearing losses.

Evaluating Police Officers’ Exposures to

Noise Generated by Gun Firing

Exercises.

HETA 92-0034-2356

October 1993

Purpose: To investigate noise exposures during gun

firing exercises.

Keywords: SIC 9221 (Police Protection), lead, firing

range, noise, ventilation.

Abstract: NIOSH investigators conducted environmental

monitoring of police officer firing exercises to assess

potential occupational exposures to hazardous noise

levels generated at the facility during the hand gun

firing exercises. Peak noise measurements ranged

from 157 to 160 dB(A) when officers were firing

their weapons on the indoor range. The hearing

protection devices used by officers are adequate

protection when they are properly maintained and

replaced when necessary. Recommendations are

provided in the report about periodic maintenance

and replacement for the hearing protection devices.
National Institute for Occupational Safety and Health 11

Evaluate of Noise and Hearing Loss in

Fire Fighters

HETA 86-138-2017

February 1990

Purpose: To investigate noise exposures and hearing

loss in fire fighters assigned to airports.

Keywords: SIC 9224 (Fire departments, including

volunteer), noise exposure, hearing loss, hearing

conservation.

Abstract: NIOSH conducted noise surveys and

audiometric examinations of fire fighters in a

metropolitan area, some of whom were assigned to

two fire stations serving a nearby airport. There was

concern that these fire fighters were at greater risk of

accruing hearing loss because of the addition of

aircraft noise to their occupational noise exposures.

The noise dosimetry results revealed timeweighted

averages that ranged from 60 to 82 dB(A). However,

the levels encountered during code three responses

(warning lights, sirens, and air horns) reached 109

dB(A) for a oneminute time period. The audiometric

results showed that the average fire fighter exhibited

a characteristic noiseinduced permanent threshold

shift. This hearing loss was statistically related to the

amount of time that the fire fighter had been on the

job, with decreasing hearing ability as a function of

years of service. NIOSH investigators conclude that

a health hazard exists for these fire fighters. A

comprehensive hearing conservation program should

be implemented in order to reduce the growth of

hearing loss for fire fighters. Specific

recommendations are presented in the full report.

Evaluation of noise exposure for two

Offices

HETA 91-0308-2376

January 1994

Purpose: To investigate excessive noise in an office

environment.

Keywords: SIC 9311 (Public Finance, Taxation, and

Monetary Policy), indoor environmental quality,

ventilation, medical questionnaire, office noise, IEQ,

GSA.

Abstract: Investigators from NIOSH conducted a health

hazard evaluation for several offices in an office

building in Michigan. Noise conditions in the office

setting were evaluated for their effects on speech

intelligibility, telephone usage, and work interruption

rather than on the risk of hearing damage. NIOSH

investigators examined noise levels and determined

that the office environments are suited for only fair to

moderate listening conditions. Recommendations

that address communication concerns are offered in

the report.

Evaluation of an Air Traffic Approach

Control Tower

HETA 96-0184-2663

November 1997

Purpose: To investigate the noise exposure of workers in

an air traffic approach control tower.

Keywords: SIC 9621 (Regulation and Administration of

Transportation Programs), air traffic control

operations-government, noise, radio headsets,

compression circuits, noise-limiting circuits,

audiometric testing, hearing conservation program.

Abstract: In this evaluation, NIOSH visited the airfield

to measure noise levels from the communication

systems used by the air traffic control (ATC)

specialists while a noise compression using was

inserted into the communication line, as well as when

the unit was removed and unattenuated signals were

allowed to reach the headset receiver. Also, ambient

background noise measurements were made in the

controllers work area. Finally, audiometric test

results from the ATC specialists and a copy of the

occupational injury and illness log were reviewed.

Analysis of the headset receiver and the compression

unit showed the controllers could be exposed to

equivalent free field noise levels up to 104 dB(A),

but that the compression units functionally reduced

the exposure to a safe level. Analysis of the

audiometric records did not reveal any systematic

occupational hearing loss in the population of

controllers. Researchers found deficiencies in the

manner in which the compression unit was used and

in the hearing tests given to the controllers. There

was a moderately high level of background noise in

the work area that could possibly interfere with

speech intelligibility. Recommendations to alleviate

these deficiencies are given in the last section of this

report.
For Information on Other

Occupational Safety

and Health Concerns

Call NIOSH at:

1-800-35-NIOSH (356-4674)

or visit the NIOSH Homepage at:

http://www.cdc.gov/niosh

DHHS (NIOSH) Publication No. 99-106