NIOSH HEALTH HAZARD EVALUATION REPORT:

DEPARTMENT OF HEALTH AND HUMAN SERVICES

Centers for Disease Control and Prevention

National Institute for Occupational Safety and Health

HETA #2000-0410-2891

STN Cushion Company

Thomasville, North Carolina

August 2002

This Health Hazard Evaluation (HHE) report and any recommendations made herein are for the specific facility evaluated and may not be universally

applicable. Any recommendations made are not to be considered as final statements of NIOSH policy or of any agency or individual involved.

Additional HHE reports are available at http://www.cdc.gov/niosh/hhe/reports

This Health Hazard Evaluation (HHE) report and any recommendations made herein are for the specific facility evaluated and may not be universally

applicable. Any recommendations made are not to be considered as final statements of NIOSH policy or of any agency or individual involved.

Additional HHE reports are available at http://www.cdc.gov/niosh/hhe/reports

This Health Hazard Evaluation (HHE) report and any recommendations made herein are for the specific facility evaluated and may not be universally

applicable. Any recommendations made are not to be considered as final statements of NIOSH policy or of any agency or individual involved.

applicable. Any recommendations made are not to be considered as final statements of NIOSH policy or of any agency or individual involved.

Additional HHE reports are available at http://www.cdc.gov/niosh/hhe/reports
ii

PREFACE

The Hazard Evaluations and Technical Assistance Branch (HETAB) of the National Institute for

Occupational Safety and Health (NIOSH) conducts field investigations of possible health hazards in the

workplace. These investigations are conducted under the authority of Section 20(a)(6) of the Occupational

Safety and Health (OSHA) Act of 1970, 29 U.S.C. 669(a)(6) which authorizes the Secretary of Health and

Human Services, following a written request from any employer or authorized representative of employees,

to determine whether any substance normally found in the place of employment has potentially toxic effects

in such concentrations as used or found.

HETAB also provides, upon request, technical and consultative assistance to Federal, State, and local

agencies; labor; industry; and other groups or individuals to control occupational health hazards and to prevent

related trauma and disease. Mention of company names or products does not constitute endorsement by

NIOSH.

ACKNOWLEDGMENTS AND AVAILABILITY OF REPORT

This report was prepared by Josh Harney, Jeffery Hess, and Doug Trout of HETAB, Division of Surveillance,

Hazard Evaluations and Field Studies (DSHEFS). Field assistance was provided by Chris Reh, Vince

Mortimer, Calvin Cook, Ann Krake, Amber Rogers, Kristin Gwin, Barbara Mackenzie, Edward Hitchcock,

and James Kesner. Analytical support was provided by Datachem Laboratories. Desktop publishing was

performed by David Butler. Review and preparation for printing were performed by Penny Arthur. 

Copies of this report have been sent to employee and management representatives at STN Cushion Co. and

the OSHA Regional Office. This report is not copyrighted and may be freely reproduced. Single copies of

this report will be available for a period of three years from the date of this report. To expedite your request,

include a self-addressed mailing label along with your written request to:

NIOSH Publications Office

4676 Columbia Parkway

Cincinnati, Ohio 45226

800-356-4674

After this time, copies may be purchased from the National Technical Information Service (NTIS) at

5825 Port Royal Road, Springfield, Virginia 22161. Information regarding the NTIS stock number may be

obtained from the NIOSH Publications Office at the Cincinnati address.

For the purpose of informing affected employees, copies of this report shall be

posted by the employer in a prominent place accessible to the employees for a

period of 30 calendar days.
iii

Highlights of the NIOSH Health Hazard Evaluation

a

a

Health Study of Workers Exposed to Bromopropane at STN Cushion

Company, Thomasville, North Carolina

NIOSH got a confidential request from workers worried about nerve problems, weakness, dizziness, leg

numbness, and headaches they thought were from glue chemicals.

What NIOSH Did

# We measured air concentrations of

1-bromopropane (1-BP) and 2-bromopropane

(2-BP) in the Fabrication area and in other

areas of the plant.

# We checked the exhaust ventilation in the

Fabrication area before and after

improvements were made to the spray tables.

# We did a medical survey that included a

questionnaire, blood and urine testing,

neurobehavioral testing, and a female

reproductive health study.

What NIOSH Found

# Air concentrations of 1-BP and 2-BP

decreased in the Fabrication area by almost

2/3 after the ventilation improvements were

made.

# Workers in the Fabrication area reported

dizziness and blurred vision more frequently

than those in other areas.

# Workerurinary bromine levels corresponded

with the airborne 1-BP concentrations.

# We could not tell if the exposures to 1-BP at

STN were related to health problems among

employees.

What STN Managers Can Do

# Purchase only 1-BP based solvent containing

the lowest possible amount of 2-BP (which is

present as a contaminant).

# Decrease unusedspace in each spray booth to

make the ventilation work as well as it can.

# Keep the Fabrication room emergency exit

door and Poly room garage door closed when

spraying glue.

# Provide gloves [not latex] that protect the

skin of Sprayers from 1- & 2-BP.

# Change work practices so that employees are

not allowed to eat or drink at their

workstations.

# Share information on potential hazards of

working with 1- & 2-BP to all workers who

can be exposed. 

What STN Employees Can Do

# Participate in all hazard communication

sessions.

# Wear the correct gloves when spraying glue.

# Wash hands before eating, drinking, or

smoking, and at the end of the day.

# Do not eat or drink at your workstation.

# If you have health effects that might be

related to the workplace you should see a

doctor experienced in occupational health

issues.

Highlights of the HHE Report
iv

What To Do For More Information:

We encourage you to read the full report. If you would like

a copy, either ask your health and safety representative to

make you a copy or call 

1-513-841-4252 and ask for

 HETA Report #2000-0410-2891

Health Hazard Evaluation Report 2000-0410-2891

STN Cushion Company

Thomasville, North Carolina

August 2002

Joshua M. Harney, MS

Jeff Hess, MD

Christopher Reh, Ph. D., CIH

Doug Trout, MD, MHS

SUMMARY

On August 28, 2000, the National Institute for Occupational Safety and Health (NIOSH) received a

confidential request for a health hazard evaluation (HHE) at STN Cushion Company (STN) in Thomasville,

North Carolina. The request was submitted by employees concerned about health effects potentially

associated with 1-bromopropane (1-BP, also called n-propyl bromide) and 2-bromopropane (2-BP, also called

isopropyl bromide) exposures during the spray application of an adhesive. The employees’ concerns centered

around neuropathy (abnormal nerve function), weakness and numbness in the lower extremities, dizziness,

and headaches.

Site visits were conducted in November 2000 (exposure monitoring and informal [confidential] employee

interviews), April 2001 (ventilation assessment), and July-August 2001 (medical evaluation and repeat

exposure and ventilation evaluations). After April 2001, STN improved the local ventilation in the area of

concern based on recommendations made by the NIOSH ventilation engineer. During both exposure

assessments, employees were monitored for full-shift 1-BP and 2-BP inhalation exposure. Short-term (15-

minute) and ceiling (5-minute) 1-BP and 2-BP inhalation exposure measurements were also collected from

the adhesive sprayers (Sprayers). Area air sampling for 1-BP and 2-BP was conducted also. The ventilation

assessments included an evaluation of local exhaust ventilation at the workstations (consisting of spray tables

and spray booths).

The medical survey, consisting of a questionnaire, a complete blood count, start-of-week and end-of -week

urine analysis for bromine, and a battery of neurobehavioral tests, was performed on all employees within the

facility who were willing to participate. Additionally, a reproductive study was performed which included all

eligible female employees who were willing to participate. The purpose of the medical survey was: 1) to

assess whether hematological (blood), neurobehavioral (postural stability and psychomotor ability), and

reproductive effects might be associated with 1-BP exposure; 2) to assess whether health effects reported

on the questionnaire were associated with 1-BP exposure; and 3) to evaluate urinary bromine levels at the
v

start and end of the week and compare these results to airborne 1-BP levels (to see if urinary bromine

concentration can be used as a biomarker of exposure). The “exposed” population consisted primarily of

those employees who worked in the Fabrication area performing spraying activities. The comparison (“less

exposed”) population consisted of all other employees who worked in the facility.

At the first site visit the mean (average) airborne 1-BP exposure for the Sprayers was 65.9 parts per million

(ppm) (range 41.3 to 143.0 ppm). The mean full-shift airborne 2-BP exposure for Sprayers was 0.66 ppm

(range 0.33 to 1.35 ppm). At the second site visit, the mean concentration of 1-BP for the Sprayers increased

from the first (16.6 ppm) to the third (23.3 ppm) day of sampling, but was lower than the concentration found

during the first site visit. Two individual spray booths (Stations #6 and #11) did, however, yield a 3-day

average exposure above a recommended level of 25 ppm. The initial ventilation assessment revealed that

all of the workstations had exhaust flow rates which were lower than recommended values. Enclosure of

spray tables led to improved ventilation at each of the workstations; however, factors were identified which

would lead to further improvement in ventilation effectiveness. 

Of the 84 individuals employed at STN at the time of the survey, 32 (38%) volunteered to participate in the

medical survey. The symptoms most often reported from all participants included: headache (reported by

48%), trouble falling asleep or staying asleep (reported by 28%), dizziness or feeling “off balance” (reported

by 25%), and blurred vision (reported by 24%). Two of the symptoms in the questionnaire, blurred vision and

dizziness or feeling “off-balance,” were significantly more common among the exposed versus the comparison

groups. Of the exposed employees, five of six reporting blurry vision and four of six reporting dizziness noted

symptom improvement during time away from the work environment.

All of the results for blood indices were within the normal value ranges provided by the testing laboratory;

however, because of the small number of blood specimens available for analysis, a statistical determination

regarding the blood tests and their relationship to 1-BP exposure could not be made. The start-of-week and

end-of-week urine bromine concentrations for the exposed group were both significantly higher than the

corresponding values for the comparison group. We found no significant elevation in urine bromine level in

the end-of-week urine samples compared to the start-of-week urine samples—in other words, we did not

detect an increase in urine bromine from the first urine sample (start-of-week) to the second urine sample

(end-of-week). Urinary bromine concentrations were highly correlated to the airborne concentration of 1-BP,

and it was concluded that urinary bromine may be a good indicator of 1-BP exposure. A total of 30

participants participated in the neurobehavioral testing. We found no differences in the Postural Stability test

results between employees in the exposed and comparison groups. Of the 16 Psychomotor Ability

parameters tested, 3 demonstrated a statistically significant difference between the exposed and comparison

groups. Specifically, we found indications of increased tremor in the right hand of participants in the exposed

group. Although we cannot determine the cause of the tremor observed by our testing, we believe that this

unilateral tremor is likely due to muscle fatigue (a known cause of the type of tremor observed), as 1-BP

exposure, if sufficient to cause tremor, would likely cause bilateral tremor (tremor on both sides) due to a

potential mechanism involving the central nervous system. And lastly, we collected insufficient data among

exposed workers in the reproductive evaluation part of the survey to be able to make any comparisons

between exposed and comparison workers in that portion of the HHE.

Although we found the Sprayers at STN to have greater exposure to 1-BP than other employees, we are

unable to determine if these exposures constitute a health hazard. By enclosing the spray booths in the

Fabrication area, STN has dramatically reduced Sprayers’ exposures to 1-BP and 2-BP. Because of
vi

symptoms consistent with excessive solvent exposure reported among the exposed workers, concerns raised

in other studies, and the lack of definitive information, efforts should continue to minimize 1-BP and 2-BP

exposures. Recommendations are provided in this report to assist in this, and include improving the ventilation

of spray booths #6 and #11 as well as improving personal protective equipment use.

Keywords: SIC Code 2392 (House furnishing, Except Curtains and Draperies); 1-bromopropane, 1-BP,

2-bromopropane, 2-BP, solvent, neuropathy, neurobehavioral, reproductive.
TABLE OF CONTENTS

Preface ....................................................................... ii

Acknowledgments and Availability of Report ............................................. ii

Summary .................................................................... iv

Introduction ................................................................... 1

Background .................................................................... 1

Methods ...................................................................... 1

Air Sampling ................................................................ 1

Ventilation Assessment ......................................................... 2

Medical Survey .............................................................. 3

Survey Population ......................................................... 3

Questionnaire ............................................................ 3

Blood .................................................................. 4

Urine .................................................................. 4

Neurobehavioral Testing ..................................................... 4

Postural Stability ....................................................... 4

Psychomotor Ability .................................................... 5

Reproductive Study ........................................................ 5

Statistical Analysis ......................................................... 6

Evaluation Criteria ............................................................... 6

1-Bromopropane and 2-Bromopropane .............................................. 7

Local Exhaust Ventilation ....................................................... 7

Results ....................................................................... 8

Air Sampling ................................................................ 8

November 2000—before enclosure of spray tables .................................. 8

July/August 2001—after enclosure of spray tables ................................... 9

Local Exhaust Ventilation ....................................................... 9

Spray Table Evaluation— November 2000—before enclosure of spray tables ................ 9

Spray Booth Evaluation— July/August 2001—after enclosure of spray tables ............... 10

Medical Survey ............................................................. 10

Questionnaire ........................................................... 10

Blood ................................................................. 10

Urine ................................................................. 11

Neurobehavioral Testing ................................................... 11

Postural Stability Testing ................................................. 11

Psychomotor Ability Testing .............................................. 11

Reproductive Evaluation .................................................... 12

Discussion ................................................................... 12

Exposure Survey ............................................................ 12
viii

Ventilation Assessment ........................................................ 12

Medical Survey ............................................................. 13

Questionnaire ........................................................... 13

Hematological Effects ...................................................... 13

Urinary Bromine ......................................................... 13

Neurobehavioral ......................................................... 14

Psychomotor Ability Testing .............................................. 14

Postural Stability Testing ................................................. 14

Survey Limitations ........................................................... 14

Conclusions .................................................................. 15

Recommendations .............................................................. 15

References ................................................................... 15

Tables ....................................................................... 19

Appendix .................................................................... 34
Health Hazard Evaluation Report No.2000-0410-2891 Page 1

INTRODUCTION

On August 28, 2000, the National Institute for

Occupational Safety and Health (NIOSH)

received a confidential request for a health hazard

evaluation (HHE) at STN Cushion Company

(STN) in Thomasville, North Carolina. The

request was submitted by employees concerned

about health effects potentially associated with 1-

bromopropane (1-BP, also called n-propyl

bromide) and 2-bromopropane (2-BP, or isopropyl

bromide) exposures during the spray application of

an adhesive. The employees’ concerns included

neuropathy (abnormal nerve function), weakness

and numbness in the lower extremities, dizziness,

and headaches. On November 14, 2000, NIOSH

investigators conducted an initial site visit at STN

which included an exposure assessment of

employees applying the adhesive and informal

(confidential) interviews to learn more about

employee health concerns. A NIOSH ventilation

engineer assessed the performance of the existing

local exhaust ventilation (LEV) in the Fabrication

area on April 18, 2001. Based on

recommendations made by NIOSH following the

April site visit, STN enclosed the spray tables on

four sides to improve the capture efficiency of the

local exhaust ventilation, thus creating ‘spray

booths.’ On July 31 to August 2, 2001, NIOSH

conducted follow-up exposure monitoring,

ventilation assessment, and medical evaluations of

workers.

In January 2002, each study participant was sent

a copy of all personal test results from the medical

evaluation. Results of the industrial hygiene

sampling were initially sent to STN and an

employee representative in letters dated February

21, 2001 (for the sampling conducted in November

2000), and September 12, 2001 (for sampling

conducted July-August 2001). A letter containing

a preliminary analysis of the data (including data

from biologic samples, neurobehavioral testing, and

the questionnaire) was distributed on May 24,

2002. This report consolidates all previous

communication, and includes up-to-date

conclusions and recommendations.

BACKGROUND

STN manufactures sofa cushions for various

furniture companies. Each cushion is assembled

by gluing together several pieces of cut flexible

foam. Once two pieces of foam are glued

together, they are hand-pressed to achieve a

proper bond. The adhesive is spray-applied using

a compressed air spray gun in the Fabrication

room. This room initially contained 13 spray

stations having a slotted LEV hood and one downdraft spray table. Following the LEV

improvements, the downdraft spray table was

discarded, and only 12 spray stations were used.

The adhesive is Whisper Spray (Imperial

Adhesives, Cincinnati, Ohio), which contains 55%

by weight 1-BP. This product also contains 1–5%

VM&P naphtha and 1–5% ethyl acetate. In

addition, small amounts of 2-BP are usually

present in most 1-BP-containing formulations.

Occasionally, a water-based spray adhesive

(Simalfa® 309, Alfa Adhesives, Inc., North

Haledon, New Jersey) that contains no

hydrocarbon solvent is used at up to four spray

stations. Adjacent to the Fabrication room are the

Saw room and the Poly room, neither of which use

the spray adhesive.

METHODS

Air Sampling

During the November 2000 exposure assessment,

employees in the Fabrication room were monitored

for full-shift inhalation exposures to 1- and 2-BP

inhalation exposure. Short-term (15-minute) and

ceiling (5-minute) 1-BP and 2-BP inhalation

exposure measurements were also collected from

the Sprayers. In addition, area air sampling for 1-

and 2-BP was conducted in the Fabrication, Saw,
Page 2 Health Hazard Evaluation Report No.2000-0410-2891

and Poly rooms to determine the degree of vapor

migration away from the spray tables. For the

inhalation exposure measurements, the sampling

pumps and sample trains were worn by the

employees, and the sample media were placed in

the subjects’ breathing zones. 

Air sampling was conducted using a NIOSH draft

sampling and analytical method for 1-BP and 2-

BP. In this method, air is drawn through a

standard charcoal tube (SKC Anasorb® CSC Lot

2000) at a nominal flowrate of 50–250 milliliters

per minute using a calibrated personal sampling

pump. After sampling, the charcoal tubes are

capped and shipped refrigerated to the analytical

laboratory. The front and back sections of the

charcoal tubes are placed in glass vials, and each

section is desorbed for 30 minutes with 1 milliliter

of carbon disulfide. Each sample is analyzed for

both 1-BP and 2-BP using gas chromatography

with a flame ionization detector.

The 1-BP limit of detection (LOD) and limit of

quantification (LOQ) were 0.001 milligram per

sample (mg/sample) and 0.004 mg/sample,

respectively. The LOD and LOQ for 2-BP are

0.001 and 0.003 mg/sample, respectively. LODs

and LOQs are values determined by the analytical

procedure used to analyze the samples, and are

not dependent on sample volume. Minimum

detectable concentrations (MDCs) and minimum

quantifiable concentrations (MQCs) are

determined by dividing the LODs and LOQs by air

sample volumes appropriate for the given set of

samples. For this HHE, the average sample

volume for a given set of samples was used to

calculate these values. MDCs and MQCs for the

full-shift exposure measurements can be found at

the bottom of Table 1, for the short-term exposure

measurements at the bottom of Table 2, for the

ceiling exposure measurements at the bottom of

Table 3, and for the area air sampling at the

bottom of Table 4. While the LODs and LOQs

are listed above in terms of mg/sample, the MDCs

and MQCs in the tables have been converted to

parts per million (ppm) to be consistent with the

evaluation criterion.

During the second exposure assessment, full-shift,

short-term, and ceiling personal breathing zone

(PBZ) samples were again collected from

Sprayers. The 1-BP LOD and LOQ for the

analytical method used were 0.0007 mg/sample

and 0.002 mg/sample, respectively. The LOD

and LOQ for 2-BP were 0.0006 and 0.002

mg/sample, respectively. MDCs and MQCs for

full-shift, short-term, and ceiling exposure

measurements from this portion of exposure

monitoring can be found at the bottom of their

respective tables (Tables 5, 6, 7) at the end of this

report. 

Ventilation Assessment

The LEV at the Sprayer’s workstations was

assessed both before and after the enclosure of

the spray tables into spray booths. For the

purposes of this report, the spray stations in the

Fabrication area will be referred to by a

numbering system. As one walks through the

plastic curtain from the Saw room into Fabrication

and turns to face the wall on the right, Station #1

is the rightmost workstation (nearest the lavatory).

Station #2 is immediately to the left of Station #1,

and shares its spray booth. Numbering then

proceeds with Station #3, immediately to the right

of Station #4. Station #4 is to the right of the exit

door. Station #5 is on the left side of this exit

door, followed in a row along the wall by Stations

#6 through #12. At the end of the Fabrication

room directly opposite Stations #1 and #2 is

Station #12, next to the doorway to the Poly room.

Two work- stations that were present during the

November 2000 survey were not during the

July/August 2001 survey (the downdraft spray

table, and a booth along the wall between the

Fabrication room door and the lavatory).

Air velocity into the LEV plena was measured

with a hot-wire anemometer (TSI® Velocicalc
Health Hazard Evaluation Report No.2000-0410-2891 Page 3

Plus, model #8360) during both evaluations.

During the November 2000 evaluation, five

velocities were recorded for each slot, giving 20

readings for each slot hood. Three rows of four

measurement points were used for the downdraft

table, and 128 readings for each double-station

hood. For computation, each 16-grid filter was

averaged separately to give 4 values for each

single-station hood, and 8 values for each doublestation hood. Additionally, air velocity 12-inches

above the work surface was measured at 6-inch

intervals out from the back wall of the workstation. Some groups of measurements were

taken more than once, and the readings were

averaged to give one set of values.

The movement of air was also observed using

“smoke tubes” (MSA #458481, Mine Safety

Appliances Company, Pittsburgh, Pennsylvania).

The direction of air movement between the inside

and the outside of the building was observed using

a smoke tube. The “smoke” was released at the

bottom of the door, and observed to note whether

it was drawn out of the building or blown in across

the floor. If the door was sealed at the bottom to

restrict air infiltration, the door was opened slightly

to check air flow along the edge.

After the April 2001 site visit, the spray tables

were enclosed to become spray booths; each

station had its own spray booth, except for #1 &

#2 and #9 & #10, which shared spray booths.

Measurements of the spray booths were made

during the July/August 2001 evaluation. Two of

the spray booths (at Stations #3 and #6) are 8' x

44" x 46". Six booths are 10' x 44" x 45"(Station

#4, #5, #7, #8, #11, #12). Two spray booths are

large enough to accommodate two spray Stations

each (#1 & #2, and #9 & #10): 14' x 43" x 45". A

thermoanemometer was used to measure the face

velocity at evenly distributed points across the

mouth of each spray booth where the Sprayer

would normally stand. Measurements were

collected under two different conditions: ‘doors

open’ and ‘doors closed.’ This refers either to

both the Poly room garage door and Fabrication

room outdoor exit door being open or both being

closed. These measurements were combined to

yield the average face velocity for each spray

booth. 

Medical Survey

The medical survey, consisting of a questionnaire,

a complete blood count, pre- and post-exposure

urine analysis for bromine, and a battery of

neurobehavioral tests was performed on all

employees within the facility who were willing to

participate. Additionally, a reproductive study was

performed and included all female employees who

were willing to participate. The purpose of the

medical survey portion of this HHE was: 1) to

assess whether objective evidence for

hematological (blood), neurobehavioral, and

reproductive adverse effects were associated with

1-BP exposure; 2) to assess whether adverse

health effects reported on the questionnaire were

associated with 1-BP exposure; and 3) to evaluate

urinary bromine levels of employees and compare
Page 4 Health Hazard Evaluation Report No.2000-0410-2891

these results to airborne 1-BP levels (to see if

urinary bromine concentration can be used as a

biomarker of exposure). The survey was

approved by the NIOSH Human Subjects Review

Board and was conducted over a three-day period

beginning on Monday, July 31, 2001. All

employees working at the facility were given the

opportunity to enroll in the survey following a 15-

minute presentation conducted at STN by NIOSH

representatives in the week prior to the survey. In

that presentation, the purpose of the study, the

tests that would be performed, and the risks and

benefits of participation were discussed.

Following the presentation, each employee was

given the opportunity to enroll in all, portions of, or

none of the study. Informed consent was obtained

from each employee choosing to participate.

Survey Population

For this survey, the “exposed” population

consisted of those employees who worked as

Fabrication Sprayers for any part of their work

shift, and employees who performed activities

other than spraying in the Fabrication area for at

least one half of their typical work shift. The

comparison (“less exposed”) population consisted

of all other employees who worked in the facility

and who did not perform activities in the

Fabrication area or who performed non-spraying

activities in the fabrication area for less than one

half of their typical work shift.

Questionnaire

On August 1, 2001, each participant was asked to

complete a questionnaire. The questionnaire

included questions concerning demographic

factors (age, gender, etc.), job factors, medical

and work history, non-occupational exposures, and

symptoms. The questionnaire was selfadministered and a NIOSH staff member was

available to explain the questions, define medical

terms for participants, and check the questionnaire

for completeness and errors. For evaluation of the

questionnaire, positive responses were determined

by a “yes” or “unsure” response to any question.

Negative responses were determined by a “no”

response.

Blood

Blood samples were analyzed for blood cell counts

because the medical literature has suggested that

exposure to brominated solvents may be

associated with pancytopenia (a decrease in the

number of all blood cell types). A 6-milliliter blood

sample was collected from each participant during

the afternoon of August 2, 2001. Venipuncture

was performed by a trained technician following

universal precautions for working with blood and

blood products.1 After venipuncture, blood

samples were placed on ice and shipped to the

NIOSH contract laboratory for analysis. Analysis

consisted of determining the white blood cell

(WBC) count, red blood cell (RBC) count, and

platelet cell (PC) count of each specimen. The

counts of these cell types were compared

between the exposed and comparison groups. 

Urine

Urine specimens were collected early in the

morning of July 31 (prior to the work shift—“startof-week” sample) and in the afternoon of August

2, 2001 (at the end of the work shift—“end-ofweek” sample). After collection, urine samples

were frozen, stored on ice, and shipped to the

NIOSH contract laboratory for analysis. Analysis

consisted of measuring the bromine and creatinine

concentration of each specimen. At present, there

is not an established normal range for the

concentration of bromine in human urine and so

values obtained were compared between the

exposed and comparison groups.

For the purposes of this HHE, pre- or postexposure urine specimens with a creatinine value

outside of the acceptable range (creatinine less

than 0.3 grams/liter [g/L] or greater than 3.0 g/L)
Health Hazard Evaluation Report No.2000-0410-2891 Page 5

were not reported or used for analysis, because

they cannot be relied upon to accurately reflect

the true body burden of bromine.2 Urinary

bromine levels were not corrected for creatinine

concentration. Start-of-week urine bromine

concentrations were compared to end-of-week

concentrations so that the change over the 3-day

period could be determined.

Neurobehavioral Testing

Neurobehavioral testing measures basic psychophysiological functions (alertness, reaction time,

memory, tremor, sensory and motor performance).

Two neurobehavioral test types (Postural Stability

and Psychomotor Ability) were used in this survey

to evaluate the presence of neurologic changes

potentially related to 1-BP exposure. Other

researchers have used these or similar tests to

evaluate neurologic changes due to solvent

exposure.3,4,5,6 Neurobehavioral testing was

chosen over electromyography (tests of individual

muscle function) because it was felt to be a more

sensitive measure of neurological change.

Analysis of each test parameter, comparing

exposed and comparison groups, was performed

to determine if a significant difference exists

between the group’s performance (between-group

analysis).

Postural Stability

Each participant was tested on a microcomputercontrolled force platform using protocols

established by NIOSH and the University of

Cincinnati.7,8,9,10 Test conditions were designed to

test the three main afferents (variables)

responsible for maintaining postural stability (e.g.,

vision, vestibular perception, and proprioception).

After one practice trial, each participant was

asked to stand on the force platform while

performing each of six different postural

maneuvers lasting 30 seconds. For the first

maneuver, participants were instructed to remove

their shoes and stand still on the platform with

arms at their sides focusing on a fixed mark on the

wall directly in front of them. The next maneuver

required the participant to maintain the same

posture but with their eyes closed. These two test

maneuvers were then repeated while the

participant stood on a 4-inch thick foam pad. The

final two test maneuvers required the participant

to stand still on one leg with eyes open, but

focusing on the fixed mark on the wall was not

required. This maneuver was then repeated while

standing on the opposite leg. Sway area and sway

length were measured during each test. Sway

area represents the area within the sway path in

square centimeters, and sway length is the length

of the sway path in centimeters.

Psychomotor Ability 

A commercially available test system (CATSYS®)

from Danish Product Development was used to

test psychomotor ability.

11 Eight tests were

selected to evaluate arm-hand tremor, simple

reaction time, and rhythmic finger/hand tapping

ability. Test procedures and device characteristics

are described in a previous NIOSH publication.12

The test researcher explained and demonstrated

each test to the participant before allowing the

individual to perform that test. Participants were

allowed to repeat a test only if they did not start

the test within 5 seconds of when the equipment

was activated and the researcher indicated the

subject should begin, or the computer determined

that there were insufficient responses during the

test period to calculate an accurate test result.

The system had a volume control which was set to

maximum volume so that any subject with hearing

difficulties could clearly hear the audible “clicks”

produced for certain tests.

Tremor was measured using a tremor pen. Each

subject held the pen first in the right hand and then

in the left hand (referred to as tremor pen right

and tremor pen left), similar to an ordinary pencil,

in front of their chest with their elbow bent at 90

degrees, and the forearm away from their body
Page 6 Health Hazard Evaluation Report No.2000-0410-2891

for a prescribed period of time while the

equipment recorded movements of the pen. Each

hand was tested twice with results from the

second test retained for data analysis. Tremor

intensity (i.e., amplitude), the root-mean square of

accelerations recorded in the 0.9 Hertz (Hz) to

15.0 Hz band during a 16-second test, and center

frequency (i.e., average frequency of

accelerations at the mid-point of the energy band)

were the principal measurements used for

analysis.

Simple auditory reaction time was assessed via a

hand-held thumb switch (referred to as reaction

time). The participant was instructed to hold the

switch in his or her dominant hand and press the

thumb switch every time he or she heard the

system produce an audible ‘click.’ The test

computer produced each ‘click’ at random

intervals for a total of 30 seconds. Mean response

latency (milliseconds) is the measurement used for

analysis. 

The rhythmic finger tapping was assessed via a

shock sensor. Each participant was instructed to

use his or her dominant hand for the test. The

palmar surface of the wrist rested on the table

surface in front of the shock sensor and the

participant was instructed not to elevate the wrist

off the table surface during the test. When the

test began the participant was to tap their index

finger on the sensor once for each audible ‘click’

produced by the test computer. The first test used

a long interval between each ‘click’ (referred to

as slow rhythmic frequency finger tap). The

second test used a short interval between each

‘click’ (referred to as fast rhythmic frequency

finger tap). The last test used a crescendo,

decreasing interval, between each ‘click’ (referred

to as maximum frequency finger tap). Rhythmic

hand tapping was assessed using the same sensor.

The participant was instructed to tap their

dominant hand on the sensor alternately using the

supinated (hand extended with palm surface up)

then pronated (hand extended with palm surface

down) surface of their dominant hand with each

‘click’ produced by the test computer. The first

test used a long interval between each ‘click’

(referred to as slow pronation/supination rhythmic

frequency). The second test used a crescendo,

decreasing interval, between each ‘click’ (referred

to as maximum frequency pronation/supination). 

Reproductive Study

The reproductive portion of this HHE was

designed to evaluate changes in women’s

hormonal cycle that might be related to 1-BP

exposure. A reproductive study of males was not

conducted at STN primarily because there is only

one male employee considered “exposed” at STN.

The study included a questionnaire, first morning

urine samples (5–10 milliliters) collected daily for

one complete menstrual cycle (or, in the event of

amenorrhea, for at least 42 days), and daily diary

documentation during the urine collection phase.

The questionnaire for this portion of the study

included questions primarily pertaining to

reproductive health history. Urine samples were

analyzed (at the NIOSH Reproductive

Endocrinology Laboratory) for luteinizing hormone

(LH), follicle stimulating hormone (FSH), and the

primary urinary metabolites of estrogen (estrone

3-glucuronide [E,3G]) and progesterone

(pregnanediol 3-glucuronide [Pd3G]). The daily

diary was used to document sample collection,

presence of menses, and use of medications or

birth control.

At the time that the questionnaire was

administered, NIOSH investigators provided each

participant with a collection kit and detailed verbal

and written instructions on the urine collection

process. Participants were instructed to store

urine samples in their own freezer (at home)

during the collection process; vials contained 7%

glycerol to prevent freeze-induced activity loss of

LH and FSH. 
Health Hazard Evaluation Report No.2000-0410-2891 Page 7

Women who volunteered in the female

reproductive health portion of the study (Phase II)

were paid $100 for participation. 

Statistical Analysis

Statistical analyses for this survey was performed

using SPSS for Windows Release 11.0.1 (SPSS

Inc., Chicago, IL). A p-value of 0.05 and 95%

confidence intervals (95% CI) which excluded the

value one were used to determine statistic al

significance. The odds ratio (OR), a measure of

the strength of association between reported

symptoms and exposure, was used to evaluate

questionnaire responses. The OR represents the

odds of an outcome in the “exposed” group

relative to the odds in the “unexposed” group. An

OR of one means there is no association between

the outcome and “exposure.” An OR of greater

than one indicates that there is evidence of an

association. For example, an OR of two would

mean that a person in the “exposed” group may

have two times the odds of reporting the outcome

than a person in the “unexposed” group.

EVALUATION CRITERIA

As a guide to the evaluation of the hazards posed

by workplace exposures, NIOSH field staff

employ environmental evaluation criteria for the

assessment of a number of chemical and physical

agents. These criteria are intended to suggest

levels of exposure to which most workers may be

exposed up to 10 hours per day, 40 hours per

week for a working lifetime without experiencing

adverse health effects. It is, however, important

to note that not all workers will be protected from

adverse health effects even though their

exposures are maintained below these levels. A

small percentage may experience adverse health

effects because of individual susceptibility, a preexisting medical condition, and/or a

hypersensitivity (allergy). In addition, some

hazardous substances may act in combination with

other workplace exposures, the general

environment, or with medications or personal

habits of the worker to produce health effects

even if the occupational exposures are controlled

at the level set by the criterion. These combined

effects are often not considered in the evaluation

criteria. Also, some substances are absorbed by

direct contact with the skin and mucous

membranes, and thus potentially increases the

overall exposure. Finally, evaluation criteria may

change over the years as new information on the

toxic effects of an agent become available.

The primary sources of environmental evaluation

criteria for the workplace are: (1) NIOSH

Recommended Exposure Limits (RELs),13(2) the

American Conference of Governmental Industrial

Hygienists’ (ACGIH®) Threshold Limit Values

(TLVs®),

14 and (3) the U.S. Department of

Labor, Occupational Safety and Health

Administration (OSHA) Permissible Exposure

Limits (PELs).15 Employers are encouraged to

follow the OSHA limits, the NIOSH RELs, the

ACGIH TLVs, or whichever are the more

protective criteria.

OSHA requires an employer to furnish employees

a place of employment that is free from

recognized hazards that are causing or are likely to

cause death or serious physical harm

[Occupational Safety and Health Act of 1970,

Public Law 91-596, sec. 5(a)(1)]. Thus,

employers should understand that not all hazardous

chemicals have specific OSHA exposure limits

such as PELs and short-term exposure limits

(STELs). An employer is still required by OSHA

to protect their employees from hazards, even in

the absence of a specific OSHA PEL.

A time-weighted average (TWA) exposure refers

to the average airborne concentration of a

substance during a normal 8- to 10-hour workday.

Some substances have recommended STEL or

ceiling values which are intended to supplement
Page 8 Health Hazard Evaluation Report No.2000-0410-2891

the TWA where there are recognized toxic

effects from higher exposures over the short-term.

1-Bromopropane and

2-Bromopropane

Laboratory studies of the toxicology of 1-BP have

shown that excessive exposure of animals to 1-BP

can lead to reproductive and neurologic effects.

The limited published information concerning

occupational exposure to 1-BP suggests

neurologic and reproductive effects in humans. A

review of the scientific literature relevant to

occupational exposure to 1-BP is presented in the

Appendix.

Currently, there are no NIOSH, ACGIH, or

OSHA exposure evaluation criteria for 1-BP.

Albemarle Corporation (a manufacturer of 1-BP)

has recommended an occupational exposure

guideline for 1-BP, based on the initial, unaudited

data from a two-generation reproductive study in

rats.16 In that study, young male and female rats

received a daily 6-hour inhalation exposure to a

known concentration of 1-BP for a minimum of 70

days. After this period, the animals were paired

for mating, and the daily exposures continued

through the 14-day mating period, and through day

20 of gestation. No litters were observed in the

750 parts per million (ppm) exposure group, and a

significant decrease was observed in the number

and size of litters in the 500 ppm exposure group.

A slight (insignificant) decrease was observed in

the mean number of pups born and live pups per

litter for the 250 ppm exposure group. Based on

these results and a 10-fold safety factor,

Albemarle set their 1-BP recommended exposure

guideline at 25 ppm as an 8-hour TWA

exposure.17

The South Korea Ministry of Labor is the only

government agency to develop an occupational

exposure level (OEL) for 2-BP. In 1998, the

Ministry issued a 2-BP OEL of 1 ppm as an 8-

hour TWA.18 This standard is based on a limited

number of workplace epidemiological studies and

toxicological (animal) studies which found that 2-

BP exposure produces reproductive effects in

both males (low sperm count) and females

(ovarian dysfunction), and also affects the

hematopoietic (blood forming)

system.19,20,21,22,23,24,25

Local Exhaust Ventilation

The velocity of air at any point in front of a hood

necessary to overcome opposing air currents and

to capture the contaminated air at that point by

causing it to flow into the hood is called the

capture velocity.

26 The velocity with which the

contaminant is released and other factors will

determine the appropriate value for the capture

velocity. For the adhesive spraying operation at

STN, the contaminant dispersion would at least be

characterized as “low velocity release into

moderately still air,” for which the range of

recommended capture velocities is 100–200

ft/min. For some workstations, the contaminant

dispersion might be better characterized as “active

generation,” for which the range of recommended

capture velocities is 200–500 ft/min.27

The lower end of these ranges is acceptable when

the air currents at the point of capture are minimal

or favorable to capture, the contaminant(s) is (are)

of low toxicity or of nuisance value only, the

production rate is low or intermittent, or the hood

is large enough to cover the work area and contain

the air mass moving toward the hood. However,

when disturbing air currents are present, the

contaminant(s) is (are) highly toxic, production

rates/contaminant-source-substance usage is high

and/or the hood is small and capable of providing

local control only, the upper end of the range is

recommended.27

For the adhesive spraying operation at STN,

although disturbing room air currents were not

prevalent, neither were they minimal or favorable
Health Hazard Evaluation Report No.2000-0410-2891 Page 9

to capture. Although not classifiable as highly

toxic, bromopropane toxicity is unknown (and was

not classified as low toxicity). Production was

fairly steady, and the hood openings did not extend

the full width of the workstations. This indicates

that the capture velocity should be at least 150

ft/min and, for some workstations, as high as 350

ft/min.

The capture velocity at the furthest point of

contaminant release in front of a hood is related to

the required exhaust air flow by the equation28

Q = 0.75v(10x2 + A)

Where: Q = the required exhaust air flow in cubic

feet per minute (cfm)

v = the capture velocity in feet per minute

(ft/min)

x = the distance in feet from the hood

face to the furthest point of contaminant

release

and A = the hood face opening area in

square feet (ft2).29 

The opening area is the width of the opening or

slots multiplied by the distance from the bottom of

the lowest slot or opening edge to the top of the

highest slot or opening edge.28

For the adhesive spraying operations in front of

the back-draft hoods, the furthest point of

contaminant release would be approximately 3 ft

in front of the back wall of the workstations. For

either: 1) the single 26-inchwide opening (7 inches

high), or 2) the four 30-inch wide slots (1 inch

high, spaced 6 inches apart), the exhaust flow rate

should be at least 10,000 cubic feet per minute

(CFM). For the down-draft table with a 21-inch

long opening, 12 inches wide, the exhaust flow

rate at 18 inches above the surface should be at

least 2700 CFM.

RESULTS

Air Sampling

November 2000—before

enclosure of spray tables

A total of 14 full-shift 1-BP and 2-BP exposure

measurements were collected from workers in the

Fabrication room (Table 1). Twelve of these

measurements were from Sprayers, and two were

from floaters. The mean (average) 1-BP air

concentration for the Sprayers was 65.9 ppm,

ranging from 41.3 to 143.0 ppm. All 12 of the

Sprayers had exposures which exceeded the

Albemarle exposure guideline of 25 ppm. The 1-

BP concentrations for the two floaters were 8.7

and 19.4 ppm.

The mean full-shift 2-BP concentration for

Sprayers was 0.66 ppm, ranging from 0.33 to 1.35

ppm. One of these concentrations exceeded the

South Korean OEL of 1 ppm. The 2-BP

concentrations for the floaters were 0.19 and 0.28

ppm.

Random short-term (15-minute) and ceiling (5-

minute) exposure measurements were obtained in

order to characterize acute 1-BP and 2-BP

exposures in Sprayers. Nine short-term exposure

measurements were obtained from Sprayers

(Table 2). The short-term 1-BP concentrations

ranged from 33.7 to 173.9 ppm, and the short-term

2-BP concentrations ranged from 0.30 to 1.56

ppm.

Eleven ceiling exposure measurements were also

obtained from the Sprayers (Table 3). The 1-BP

ceiling concentrations ranged from 39.5 to 151.9

ppm, and the 2-BP concentrations ranged from

0.37 to 1.13 ppm. 
Page 10 Health Hazard Evaluation Report No.2000-0410-2891

Finally, full-shift area air sampling was conducted

in the Fabrication, Saw, and Poly rooms to

determine the 1-BP and 2-BP room

concentrations, and to determine the extent to

which these compounds are migrating to adjacent

areas. These data are shown in Table 4. The 1-

BP and 2-BP concentrations in the Fabrication

room were 7.2 and 0.11 ppm respectively. In

addition, the 1-BP concentrations in the Saw and

Poly rooms were 7.7 and 1.7 ppm, and the 2-BP

concentrations were 0.20 and 0.05 ppm

respectively.

July/August 2001—after

enclosure of spray tables

Cushion production reportedly was slightly below

normal at the beginning of this survey (July 31,

2001), but increased roughly 20% each of the next

two days. Results from full-shift air sampling

done each day are listed in Table 5. The mean

concentration of 1-BP for the Sprayers increased

from the first (16.6 ppm) to the third (23.3 ppm)

day of sampling, but was lower than the

concentration found during the first site visit; the

mean 2-BP concentration did not vary widely. For

each day of sampling, the mean concentration of

the Sprayers as a group was below the exposure

limit suggested by Albemarle. Two individual

spray booths (Stations #6 and #11) did, however,

yield a 3-day average exposure above 25 ppm for

the workers at those particular booths.

Table 6 lists short-term (15 minute) exposures of

the Sprayers. Concentrations for 1-BP ranged

from 0.2 ppm, for the Sprayer at booth #11, who

did not spray much during this 15 minute period, to

56 ppm. 2-BP short-term concentrations ranged

from trace (between 0.04-0.13 ppm) to 0.4 ppm.

Table 7 lists the Sprayers’ 5-minute ceiling

exposures. Concentrations ranged from ‘not

detected’ (below 0.14 ppm) to 38 ppm for 1-BP,

and from ‘not detected’ (below 0.12 ppm) to 0.5

ppm for 2-BP.

Air sampling results for non-Sprayers are listed in

Table 8. Several PBZ and general area (GA)

samples were collected each day. 1-BP

concentrations ranged from 0.01 ppm (GA

samples collected outside the building) to 6.1 ppm

(GA sample collected on the saw room I-beam

closest to the doorway to the assembly area). 2-

BP concentrations were 0.1 ppm or less in all

samples. These results indicate that at least some

solvent vapor appears to be present in areas of the

plant away from the Fabrication area.

Local Exhaust Ventilation

Spray Table Evaluation—

November 2000—before

enclosure of spray tables

The capture velocity 3 ft in front of the thirteen

back-draft hoods in the Fabrication area ranged

from 6 ft/min to 73 ft/min, and the capture velocity

18 inches above the down-draft table (station # 6)

was 26 ft/min. (See Table 9) The calculated

exhaust flow rates for each hood (also listed in

Table 9) ranged from 230 CFM to 1545 CFM. All

of the values are less than the recommended

values (as discussed in the Evaluation Criteria

section).

Consistent with the low exhaust flow rates and

capture velocities, air-flow visualization revealed

that the hoods performed only marginally well with

air flowing toward the back of the workstations at

some, but not all, locations across the face of each

work- station. Moreover, except for the hood with

the greatest air flow, for which all smoke released

at the front edge of the workstation was

“captured,” contaminants released at one (or both)

edge(s) of each of the other workstations would

drift lazily away into the workroom. The external

foam filter covering some of the openings did not

seem to greatly affect the flow of air in front of

the hoods.
Health Hazard Evaluation Report No.2000-0410-2891 Page 11

Observed work practices revealed that pieces of

foam for seat cushions were stacked in front of

the slot hoods at some workstations, preventing

adhesive spraying in the region of the workstation

where exhaust ventilation would be most

effective. Some large pieces blocked the local

exhaust ventilation slots while being sprayed with

adhesive, restricting the effectiveness of the local

exhaust ventilation.

Spray Booth Evaluation—

July/August 2001—after

enclosure of spray tables

Table 10 shows the average capture velocity

measured at each spray booth under two sets of

conditions: ‘doors open’ and ‘doors closed.’

Capture velocities at the spray booths ranged from

18 ft/min (Station #12) to 70 ft/min (Stations #1 &

#2) with the doors closed. Operating with the

doors closed did not have a clear effect on the

capture velocity of all the spray hoods compared

to when the doors were open. 

Medical Survey

Questionnaire

Of the 84 individuals employed at STN at the time

of the survey, 32 (38%) volunteered to participate

in the medical survey. A total of 30 (36% of the

84) employees completed the study questionnaire;

included in this number were 12 (92%) of 13

employees in the exposed group, and 18 (25%) of

71 in the comparison group. Table 11 lists

selected characteristics of participating employees

who completed the questionnaire. Of note, the

employees in the groups were primarily women,

and were of similar age. Employees in the

exposed group had a mean length of employment

at STN of 13 years, compared to 21 years for

employees in the comparison group. Two (17%)

in the exposed group and 7 (39%) in the

comparison group provided positive answers to the

question concerning exposure (occupationally or

through other activities) to other substances of

concern (defined in the questionnaire as arsenic,

mercury, lead, cadmium, solvents, or pesticides).

The two subjects from the exposed group

responding positively to this question had marked

“don’t know” as their response and did not give

any further detail concerning their exposure in the

explanation section.

Regarding data collected concerning work

practices, 92% of exposed workers responded

they always wore some type of protective clothing

(such as an apron) while working; our observation

of work practic es revealed that the aprons worn

did not protect the arms from contact with

solvents. Two (17%) exposed and 1 (6%)

comparison subject responded that they smoked

“sometimes” or “rarely” in the work area. Sixteen

percent of the exposed group washed their hands

“always” or “sometimes” before smoking and

after performing work activities. All participants

reported that they washed their hands before

eating or chewing gum after performing work

activities. 

Table 12 presents data concerning reported

symptoms by exposure status (exposed versus

comparison group). The symptoms most often

reported from all participants included: headache

(reported by 48%), trouble falling asleep or staying

asleep (reported by 28%), dizziness or feeling “off

balance” (reported by 25%), and blurred vision

(reported by 24%). The data in Table 12 reveal

that two of the symptoms in the questionnaire had

a statistically significant odds ratio between the

exposed and comparison groups (indicating that

those two symptoms were reported more

commonly among the exposed employees versus

the comparison group). The exposed group

reported 16 times the odds of experiencing blurred

vision (95% CI 1.6 - 162), and 15 times the odds

of experiencing dizziness or a feeling of being “off

balance” (95% CI 1.5 - 153) within the last 30
Page 12 Health Hazard Evaluation Report No.2000-0410-2891

days. None of the odds ratios for the remaining

symptoms were statistically significantly elevated.

Of the exposed employees, five of six reporting

blurry vision and four of six reporting dizziness

noted symptom improvement during time away

from the work environment. Two of six reporting

blurry vision and two of six reporting dizziness

reported experiencing that symptom on the day the

questionnaire was administered. 

Blood

A total of 24 (29% of the 84 total employees)

participants agreed to have their blood drawn.

Within this group, venipuncture was unsuccessful

on three participants, and 9 of the samples

collected clotted before arriving at the lab, making

these specimens unsuitable for analysis.

Consequently, only 3 (23%) of 13 exposed, and 9

(13%) of 71 comparison blood samples were

available for analysis. All of the results for WBC,

CBC, and PC were within the normal value range

provided by the testing laboratory.

30

 No

statistically significant differences were detected

between the means of the blood indices for the

exposed and comparison groups.

Urine

A total of 23 (27% of 84) participants provided

start-of-week and end-of-week urine specimens.

Within this group 4 partic ipants were unable to

provide a start-of-week specimen and 2

participants were unable to provide an end-ofweek specimen. One specimen was excluded

from analysis because it had a creatinine

concentration that fell outside the acceptable

range for this analysis (indicating that it cannot be

relied upon to accurately reflect the true body

burden of bromine). Consequently, there were 6

(46%) of 13 exposed and 10 (14%) of 71

comparison paired urine specimens available for

analysis.

Results of the urine bromine statistical analyses

are in Table 13. The start-of-week and end-ofweek urine bromine concentrations for the

exposed group were both statistically significantly

higher than the corresponding values for the

comparison group (p < 0.01). We found no

significant elevation in urine bromine level in the

end-of-week urine samples compared to the startof-week urine samples—in other words, we did

not detect an increase in urine bromine from the

first urine sample (start-of-week) to the second

urine sample (end-of-week). Regression analysis

of both start-of-week and end-of-week urinary

bromine concentrations versus personal breathing

zone air concentrations of 1-BP demonstrated a

statistically significant positive correlation. 

Neurobehavioral Testing 

A total of 30 participants participated in the

neurobehavioral testing portion of the study;

included in this number were 12 (92%) of 13

exposed, and 18 (25%) of 71 comparison

employees.

Postural Stability Testing

Not all study subjects were able to complete the

entire Postural Stability test battery. Six subjects

(one from the exposed group) were unable to

stand on either their right or left leg for a long

enough period of time to complete both of the last

two tests. Three subjects (all in the comparison

group) were unable to stand for a long enough

period of time on either their right or left leg to

complete one of the last two tests. We found no

differences in the Postural Stability test results

between employees in the exposed and

comparison groups.

Psychomotor Ability Testing

Results for each of the Psychomotor Ability tests

can be found in Table 14. Every employee taking

part in the neurobehavioral testing completed the
Health Hazard Evaluation Report No.2000-0410-2891 Page 13

entire Psychomotor Ability test battery. Of the 16

parameters tested, 3 demonstrated a statistically

significant difference between the exposed and

comparison groups. In each case the mean test

value was higher (demonstrating increased effect)

in the exposed group. These three parameters

included right tremor pen intensity, right tremor

pen frequency, and slow rhythmic frequency

finger tap standard deviation. 

Regression analysis of each of these variables

(right tremor pen frequency, right tremor pen

intensity, and standard deviation of slow rhythmic

frequency finger tap) against PBZ air

concentrations of 1-BP demonstrated a

statistically significant positive correlation only for

right tremor pen frequency. No statistically

significant correlation was demonstrated for right

tremor pen frequency when compared against

urine bromine concentrations, and neither of the

other two variables mentioned above (right tremor

pen intensity or slow rhythmic frequency finger

tap standard deviation) demonstrated a statistically

significant correlation with any of the measures of

exposure.

Reproductive Evaluation

Ten women agreed to participate in the

reproductive portion of the evaluation. Four of the

women did not finish the study or provide urine

samples or diaries. Only one of the women who

completed the study was in the exposed group

(working in the Fabrication area); all the others

were in the comparison (less exposed) group.

Additionally, upon analysis of the urine specimens,

it became apparent that the one exposed worker

did not follow the correct procedure for urine

collection. Therefore, none of the data we

collected for this portion of the survey was able to

be compared between exposed and comparison

workers, and we will not be able to make any

determinations of potential female reproductive

effects of 1-BP exposure in this HHE. The

results of these menstrual cycle function analyses

have been provided to the participants.

DISCUSSION

Exposure Survey

The 1-BP exposure data from the November 2000

sampling indicated that all 12 Sprayers had fullshift 1-BP exposures above the Albemarle

exposure guideline of 25 ppm. Considering these

findings, and the results of our ventilation

assessment, the NIOSH investigators concluded

that the LEV system was not adequately removing

or controlling the 1-BP vapors. Additionally, the

area air sampling data indicated that low

concentrations of 1-BP and 2-BP were migrating

to nearby areas. Follow-up air sampling in

July/August 2001, revealed decreased mean 1-BP

exposure of Sprayers by over 60% (22.5 ppm vs.

62.1 ppm). 2-BP exposures also decreased over

60% (0.2 ppm vs. 0.62 ppm). However,

measurements at two spray booths (Station #6 and

#11) revealed concentrations of 1-BP that

remained above the Albemarle exposure guideline.

Our observation of work practices at those

stations indicates that individual work habits of

Sprayers (e.g., the amount of adhesive sprayed on

each cushion) are likely important factors

contributing to the higher exposures observed at

those two spray booths. 

Of note, some work practices which might have

been expected to affect measured PBZ exposures

appeared not to have a measurable impact in our

survey. For example, some Sprayers stayed at

their workstations during their morning, lunch,

and/or afternoon breaks, while others left the

Fabrication room and went outdoors or to other

areas of the building. Additionally, Station #3, #6,

#8, and #12 were set up to use a water-based

spray adhesive (not containing 1-BP), which if

used extensively during the day could result in

decreased BP exposures for workers. However,
Page 14 Health Hazard Evaluation Report No.2000-0410-2891

the water-based spray adhesive was used only

sporadically during this survey, and had no obvious

effect on BP exposures received by the Sprayers

using it.

Some Sprayers used natural latex rubber gloves to

prevent adhesive from getting on their skin. While

this may be effective in keeping adhesive off their

skin, it does not protect against dermal exposure to

1-BP and 2-BP. At least one manufacturer of BP

products recommends using gloves made of

flexible laminates, such as Viton®.31 

Ventilation Assessment

Whenever there is a potential for a hazardous

exposure in a workplace, traditional industrial

hygiene practice dictates that the following

hierarchy of controls, in decreasing order of

desirability and effectiveness, be implemented to

protect worker health:

1. Elimination of the toxic substance from

the workplace.

2. Substitution of the toxic substance with a

less toxic substance. 

3. Installation of engineering controls

designed to reduce exposure.

4. Use of administrative controls to reduce

exposure.

5. Use of personal protective equipment to

reduce exposure.

In many instances, it is not possible to eliminate or

substitute a chemical or material from a production

process without altering the integrity of the desired

product. Thus, many strategies for reducing

hazardous exposures center on the use of

engineering controls such as process isolation

and/or local exhaust ventilation. At STN, 1-BP

vapors have largely been controlled using the

spray booths at each workstation, with each booth

discharging the captured air and vapors outside of

the building. While spray booth operation as of the

August 2001 site visit was an improvement over

conditions observed during the NIOSH survey of

November 2000, two things can be done to further

improve LEV effectiveness. With the Poly room

garage door and Fabrication room outdoor exit

door closed, the plastic curtain separating the

Assembly room from the Saw room began

flapping due to the dramatic increase in airflow

through this doorway into the Fabrication room.

This did not occur with the doors open. Keeping

the doors closed is therefore more likely to

minimize the migration of solvent vapors into the

Saw room and rest of the building. Also, there

appeared to be a large amount of unused space in

several of the spray booths. Minimizing the

unused volume within each spray booth, while not

decreasing the work space so much that cushion

assembly is hindered, will result in an increase in

face velocity, without changing the exhaust fan

speed, duct size, etc.

Medical Survey

Questionnaire

Blurry vision and dizziness were reported more

commonly among the workers exposed to 1-BP

compared to those who were less exposed.

Additionally, five of the six workers reporting

blurry vision, and four of the six reporting

dizziness, reported that the symptoms resolved

after leaving the work environment. Previous

studies have demonstrated vision changes related

to solvent exposure,32,33 and other studies have

found that chronic mixed solvent exposure can

cause an increase in the subjective symptom of

dizziness.34,35 One of the two published case

reports concerning occupational 1-BP exposure

did mention that individuals reported experiencing

dizziness during exposure, but neither of the

published reports noted exposed persons reporting

blurry vision.20,21 The blurry vision and dizziness

reported in our questionnaire, however, are

nonspecific symptoms which could have many

potential causes, and the low participation rate in
Health Hazard Evaluation Report No.2000-0410-2891 Page 15

the study makes it difficult to determine whether

these findings are generalizable to the overall

study population.

Hematological Effects

Our evaluation detected no association between

occupational exposure to 1-BP and changes in

hematological indices; however, because of the

small number of blood specimens available for

analysis, we cannot make a definite determination

regarding the blood test results and their

relationship to 1-BP exposure.

Urinary Bromine

Our survey demonstrated that airborne 1-BP

concentrations were correlated with both start-ofweek and end-of-week urine bromine

concentrations. This finding is consistent with the

findings of a previous 1-BP biological monitoring

study.

36 However, we did not demonstrate an

increase in urine bromine concentrations in the

end-of-week sample compared to the start-ofweek sample for individuals or the group as a

whole. Possible explanations for this finding are:

1) bodily elimination of bromine via the kidneys

may be slow, so that exposure to airborne 1-BP

over a 3-day period (the time over which we

collected our samples) does not affect urinary

bromine concentration at a level we can detect;

and 2) exposure to 1-BP in the time period prior to

our survey may have been greater than that during

our survey, leading to declining urine bromine

levels (reflecting the decreased exposure).

Neurobehavioral 

Psychomotor Ability Testing

In our survey the neurobehavioral test parameters

for frequency and intensity of tremor in the right

hand were increased in the exposed group; right

hand tremor frequency alone was correlated with

airborne 1-BP concentrations. Many different

types of occupational exposures, including

exposure to solvents, have been associated with

tremor.

37 In general, tremors related to toxic

exposures are thought to be due to effects of the

toxins on the central nervous system and not the

peripheral nervous system.38,39 If 1-BP were to

have the same type of central mechanism, it is not

likely that overexposure to 1-BP would cause a

unilateral tremor (tremor of one hand/arm and not

the other), which was the type of tremor our

testing detected. Our findings of increased

unilateral tremor among the exposed workers

could be related to muscle fatigue of the right hand

and arm. Holding an adhesive spray gun

(weighing 1 to 1.5 pounds) in one hand

c onsistently while performing job activities could

fatigue the muscles of that hand, arm and

shoulder. Because the exposed group was tested

late in the work day (after performing job activities

for 4–6 hours), it is likely that some level of hand

or arm fatigue was present in these individuals.

Muscle fatigue can cause a mild tremor, which the

tremor pen test is sensitive enough to detect, and

the pen tremor test is unable to distinguish

between muscle fatigue tremor and neurological

based tremor of the hand and arm. We did not

collect information concerning participants’

dominant hand, or which hand they preferred to

use when holding the adhesive spray gun, so we

are unable to directly address that issue. 

The time frame over which our tests were

administered makes it impossible for us to

distinguish whether the tremor detected might be

due to an acute or chronic condition or effect. It
Page 16 Health Hazard Evaluation Report No.2000-0410-2891

is possible that, in some cases, the tremor we

noted is a result of a chronic neurological condition

unrelated to current work activities or exposures

(and which may have existed prior to work at

STN). Therefore, for all the reasons listed above,

we are not able to determine the cause(s) of the

tremor we observed with our medical testing.

A third parameter, the standard deviation of slow

rhythmic frequency finger tap, was also increased

in the exposed group versus the comparison group.

However, because the corresponding test

parameter, slow rhythmic frequency finger tap

mean, was not increased in the exposed group, it

is likely that the finding related to the standard

deviation is not meaningful.

Postural Stability Testing

The postural sway studies we conducted failed to

demonstrate any significant difference in balance

between test groups despite the fact that the

symptom of dizziness was reported more

frequently among the exposed group. One

possible reason for this could be that the

“dizziness” reported in the questionnaire actually

represented symptoms consistent with

“lightheadedness,” rather than vertigo or altered

balance. Additionally, the questionnaire addressed

symptoms occurring within the 30 days prior to our

evaluation. If the symptom was transient (not

oc curring on the day of testing) the reported

symptoms would not necessarily correlate with

objective testing.

Survey Limitations

The ability of this survey to detect any potential

associations between 1-BP exposure and health

effects was limited by several factors in addition

to those limitations listed above. The first

limitation was the small number of partic ipants,

decreasing our ability to detect differences

between the exposed and comparison groups if

they in fact existed. A second limitation was the

low participation rate, which could lead to a

selection bias (persons who participated may not

be representative of all the workers). A third

limitation involves the fact that the 1-BP

exposures at STN were moderate in comparison

to other facilities in the U.S., particularly after

ventilation improvements were made at the plant.

CONCLUSIONS

Although we found the Sprayers at STN to have

greater exposure to 1-BP than other employees

doing different work, we are unable to determine

if these exposures constitute a health hazard.

Further investigation of potential health effects

related to occupational exposure to 1-BP is

needed before any definitive conclusions can be

made. Nevertheless, because of symptoms

reported in our survey which are consistent with

known effects of solvents, and because of

concerns raised in other studies, until more

definitive information is available we believe that

every reasonable effort should be taken to

minimize 1-BP exposures. By enclosing the spray

booths in the Fabrication area, STN has

dramatically reduced Sprayers’ exposures to 1-BP

and 2-BP, as evidenced by reductions in full-shift,

short-term, and ceiling exposures measured before

and after LEV improvements were made.

Improvements in the ventilation of spray booths #6

and #11 are needed to bring those workstations up

to the level of the remainder of the stations. We

also found that the latex gloves used by Sprayers

do not protect them from dermal exposure to 1- or

2-BP. Regarding our survey of urinary bromine

concentrations, we found that urinary bromine

concentrations were highly correlated to the

airborne concentration of 1-BP to which

individuals were occupationally exposed at this

facility. We conclude that urinary bromine may be

a good indicator of 1-BP exposure, however,

further research is needed to confirm our findings.
Health Hazard Evaluation Report No.2000-0410-2891 Page 17

1. CDC [1989]. Guidelines for prevention of

transmission of human immunodeficiency virus

and hepatitis B virus to health-care and public

safety workers. MMWR 37(suppl. S-6):1–37.

2. Szava K [2001]. Personal communication.

Email of July 16, 2001, from S. Szava, Director of

Education, American Conference of

Governmental Industrial Hygienists Worldwide

(ACGIH®), to J. Nemhauser, Medical Officer,

Medical Section, Hazard Evaluations and

Technical Assistance Branch, National Institute

for Occupational Safety and Health, Centers for

Disease Control and Prevention, Public Health

Service, U.S. Department of Health and Human

Services.

3. Dick RB, Setzer JV, Taylor BJ, Shukla R

[1989]. Neurobehavioral effects of short duration

exposures to acetone and methyl ethyl ketone. Br

J Ind Med 46:111–121.

4. Dick RB, Setzer JV, Wait R, Hayden MB,

Taylor BJ, Tolos B, Putz-Anderson V [1984].

Effects of acute exposure of toluene and methyl

ethyl ketone on psychomotor performance.

International Archives of Occupational

Environmental Health 54:91–109.

5. Dick RB, Kreig EF Jr., Setzer J, Taylor B

[1992]. Neurobehavioral effects from acute

exposures to methyl isobutyl ketone and methyl

ethyl ketone. Fundamental and Applied Toxicology

19:453–473.

6. Mikkelsen S, Jorgensen M, Browne E,

Gyldensted C [1989]. Mixed solvent exposure and

organic brain damage. A study on painters. Acta

Neurologica Scandinavica Supplement 118:1–143.

RECOMMENDATIONS

The following recommendations are made to assist

in minimizing worker exposure to 1-BP (and 2-

BP).

1) STN should continue investigating the use of

non-hydrocarbon solvent adhesives. This may

require experimentation with the flow of cushion

parts within Fabrication, since the water-based

adhesives do not ‘set up’ as quickly as does the

current adhesive most frequently used at STN.

2) When buying a 1-BP based adhesive, STN

should choose the one with the lowest amount of

residual 2-BP.

3) STN should provide Fabrication Sprayers with

gloves that protect against dermal exposure to 1-

BP and 2-BP; materials to consider include gloves

and aprons made from flexible laminates (e.g.,

VitonTM, 4HTM (PE/EVAL), Silver ShieldTM).

4) The Fabrication room outdoor exit and the Poly

room garage doors should remain closed so that

vapor migration into other areas of the building is

minimized. 

5) The unused volume in each spray booth should

be decreased as much as possible to optimize the

current ventilation. This should increase the LEV

capture velocity and further lower worker

exposures.

6) Sprayers, and other employees using chemicals,

should not eat or drink at their workstations. 

7) The findings of our medical survey do not by

themselves indicate that medical follow-up is

needed for any specific employees or groups of

employees. However, employees who are

experiencing health effects potentially related to

the workplace should be evaluated by a healthcare

provider who has experience with occupational or

environmental health issues.

REFERENCES
Page 18 Health Hazard Evaluation Report No.2000-0410-2891

7. Dick RB, Bhattacharya A, Shukla R [1990].

Use of a computerized postural sway

measurement system for neurobehavioral

toxicology. Neurotoxicology and Teratology

12:1–6.

8. NIOSH [1995]. Research

Protocol-DBBS-95-02: Neurobehavioral health

risks in farmworkers. Cincinnati, OH: U.S.

Department of Health and Human Services,

Public Health Service, Centers for Disease

Control and Prevention, National Institute for

Occupational Safety and Health.

9. Bhattacharya A, Morgan R, Shukla R,

Rarnakrishanan H K, Wang L [1987].

Noninvasive estimation of afferent inputs for

postural stability under low levels of alcohol.

Annals Biomed Eng 15:533–550.

10. Bhattacharya A, Shukla R, Dietrich K,

Bornschein R, Berger O [1995]. Effect of early

lead exposure on children's postural balance.

Developmental Med Child Neurol 37:861–878.

11. Danish Product Development Ltd. [1994].

TREMOR 3.0 Users Manual. Snekkersten,

Denmark.

12. NIOSH [1999]. Hazard evaluation and

technical assistance report: Mercury Waste

Solutions, Inc., Union Grove, WI. Cincinnati, OH:

U.S. Department of Health and Human Services,

Public Health Service, Centers for Disease

Control and Prevention, National Institute for

Occupational Safety and Health, NIOSH HETA

Report No. 1998-0320-2751.

13. NIOSH [1992]. Recommendations for

occupational safety and health: compendium of

policy documents and statements. Cincinnati, OH:

U.S. Department of Health and Human Services,

Public Health Service, Centers for Disease

Control and Prevention, National Institute for

Occupational Safety and Health, DHHS (NIOSH)

Publication No. 92-100.

14. ACGIH [2002]. 2002 TLVs® and BEIs®:

threshold limit values for chemical substances and

physical agents. Cincinnati, OH: American

Conference of Governmental Industrial

Hygienists.

15. CFR [2002]. 29 CFR 1910.1000. Code of

Federal Regulations. Washington, DC: U.S.

Government Printing Office, Office of the Federal

Register.

16. Stump D [2001]. An inhalation twogeneration reproductive toxicity study of 1-

bromopropane in rats. Study No. WIL-380001.

Ashland, OH: WIL Research Laboratories.

Unpublished. (Study sponsored by Brominated

Solvents Consortium [BSCO]).

17. Smith RL [2000]. Presentation titled “NPropyl Bromide” which was given on November

6, 2000, at a meeting between the U.S.

Environmental Protection Agency and the

Brominated Solvents Consortium.

18. Korean Ministry of Labour [2002]: Regulation

on threshold limit values for chemical substances

and physical agents. Announcement No. 2002-8.

Korean Ministry of Labour, Seoul, Korea.

19. Park JS, Kim Y, Park DW, et al. [1997]. An

outbreak of hematopoietic and reproductive

disorders due to solvents containing 2-

bromopropane in an electronic factory, South

Korea: epidemiological survey. J Occup Health

39:138–143.

20. Kim Y, Jung K, Hwan T, et al. [1996].

Hematopoietic and reproductive hazards of South

Korean electronics workers exposed to solvents

containing 2-bromopropane. Scand J Work

Environ Health 22:387–391.

21. Ichihara Y, Yu S, Kamijima M, et al. [1997].

An occupational health investigation of a factory

producing 2-bromopropane in China. J Occup

Health 39 suppl: S327.
Health Hazard Evaluation Report No.2000-0410-2891 Page 19

22. Ichihara G, Aseda N, Kumazawa T, et al.

[1997]. Testicular and hematopoietic toxicity of

2-bromopropane, a substitute for ozone layer

depleting chlorofluorocarbons. J Occup Health

39:57–63.

23. Kamijima M, Ichihara G, Yu X, et al. [1997].

Disruption of ovarian cyclicity due to

2-bromopropane in the rat. J Occup Health

39:3–4.

24. Yu IJ, Chung YH, Lim CH, et al. [1997].

Reproductive toxicity of 2-bromopropane in

Sprague Dawley Rats. Scand J Work Environ

Health 23:281–288.

25. Lim CH, Maeng SH, Lee JY, et al. [1997].

Effects of 2-bromopropane on the female

reproductive function in Sprague Dawley rats. Ind

Health 35:278–284.

26. ACGIH [1998]. Industrial Ventilation. 23rd

ed., A Manual of Recommended Practice.

Cincinnati, OH: American Conference of

Governmental Industrial Hygienists. Fig 3-1, p.

3-3.

27. ACGIH [1998]. Industrial Ventilation. 23rd

ed., A Manual of Recommended Practice.

Cincinnati, OH: American Conference of

Governmental Industrial Hygienists. Table 3-1, p.

3-6.

28. ACGIH [1998]. Industrial Ventilation. 23rd

ed., A Manual of Recommended Practice.

Cincinnati, OH: American Conference of

Governmental Industrial Hygienists. Fig 3-11, p. 3-

12.

29. ACGIH [1998]. Industrial Ventilation. 23rd

ed., A Manual of Recommended Practice.

Cincinnati, OH: American Conference of

Governmental Industrial Hygienists. Fig 3-8, p.

3-9.

30. Normal range values for hematologic indices,

Medtox Laboratories, Inc., St. Paul, MN, August

7, 2001.

31. Ensolv MSDS. World Wide Web

[URL=www.ensolv.com. ], August 27, 2001. 

32. Yasugi T, Kawai T, Mizunuma K, Kishi R,

Harabuchi I, Yuasa J, Eguchi T, Sugimoto R, Seiji

K, Ikeda M [1994]. Exposure monitoring and

health effect studies of workers occupationally

exposed to cyclohexane vapor. International

Archives of Occupational & Environmental Health

65(5):343–350.

33. Kishi R, Eguchi T, Yasugi T, Katakura Y,

Arata Y, Harabuchi I, Kawai T, Masuchi A

[2001]. Effects of low-level occupational exposure

to styrene on color vision: dose relation with a

urinary metabolite. Environmental Research

85(1):25–30.

34. Horstman SW, Browning SR, Szeluga R,

Burzycki J, Stebbins A [2001]. Solvent exposures

in screen printing shops. Journal of Environmental

Science & Health Part A—Toxic/Hazardous

Substances & Environmental Engineering

36(10):1957–1973.

35. Juntunen J [1993]. Neurotoxic syndromes

and occupational exposure to solvents.

Environmental Research 60(1):98–111.

36. Kawai T, Takeuchi A, Miyama Y, Sakamto

K, Zhang ZW, Higashikawa K, Ikeda M [2001].

Biological monitoring of occupational exposure to

1-bromopropane by means of urinalysis for 1-

bromopropane and bromide ion. Biomarkers

6(5):303–312.

37. Dick F, Semple S, Chen R, Seaton A [2000].

Neurological deficits in solvent-exposed painters:

a syndrome including impaired colour vision,

cognitive deficits, tremor and loss of vibration

sense. QJM 93(10):655–661.
Page 20 Health Hazard Evaluation Report No.2000-0410-2891

38. Troster AI, Woods SP, Fields JA, Lyons KE,

Pahwa R, Higginson CI, Koller WC [2002].

Neuropsychological deficits in essential tremor: an

expression of cerebello-thalamo-cortical

pathophysiology? Eur J Neurol 9(2):143–51.

39. Deuschl G, Bergman H [2002].

Pathophysiology of nonparkinsonian tremors. Mov

Disord 17 (Suppl 3):S41–48.
Health Hazard Evaluation Report No.2000-0410-2891 Page 21

Table 1

Full-Shift PBZ air sampling results for 1- and 2-BP

STN Cushion Company

Thomasville, North Carolina

HETA 2000-0410-2891

November 14, 2000

Tables

Job Title Department

Sample

Time

(min.)

Sample

Volume

(L)

Concentration, ppm, 8-hr.

TWA

1-BP 2-BP

Sprayer Fabrication 498 25.0 41.3* 0.5*

Sprayer Fabrication 496 25.0 143.0* 1.4*

Sprayer Fabrication 495 25.0 74.7* 0.8*

Sprayer Fabrication 296 15.0 29.4 0.2

Sprayer Fabrication 494 24.9 73.4* 0.7*

Sprayer Fabrication 487 24.5 48.6* 0.5*

Sprayer Fabrication 492 24.9 75.8* 0.8*

Sprayer Fabrication 494 24.9 78.3* 0.7*

Sprayer Fabrication 491 24.8 51.3* 0.6*

Part Time Fabrication 350 17.5 34.7 0.4

Part Time Fabrication 282 14.1 32.3 0.3

Part Time Fabrication 350 17.5 41.3 0.5

Floater Fabrication 345 17.3 6.3 0.1

Floater Fabrication 349 17.5 14.1 0.2

Recommended exposure guideline 25 1 

Minimum Detectable Concentration (MDC) 0.01 0.01

Minimum Quantifiable Concentration (MQC) 0.03 0.02

* For sampling periods longer than 8 hrs., the average concentrations for the time sampled is given.
Page 22 Health Hazard Evaluation Report No.2000-0410-2891

Table 2

Short Term (15-minute) PBZ air sampling results for 1- and 2-BP

STN Cushion Company

Thomasville, North Carolina

HETA 2000-0410-2891

November 14, 2000

Job Title Department

Sample

Time

(min)

Sample

Volume

(L)

Concentration, ppm

1-BP 2-BP

Sprayer Fabrication 17 3.4 173.9 1.56

Sprayer Fabrication 17 3.4 110.1 1.04

Sprayer Fabrication 16 3.2 55.4 0.54

Sprayer Fabrication 16 3.2 92.3 0.98

Sprayer Fabrication 15 3.0 72.2 0.62

Sprayer Fabrication 15 3.0 33.7 0.38

Sprayer Fabrication 15 3.0 42.6 0.3

Sprayer Fabrication 15 3.0 65.6 0.54

Sprayer Fabrication 15 3.0 138.5 1.05

Minimum Detectable Concentration (MDC) 0.06 0.06

Minimum Quantifiable Concentration (MQC) 0.23 0.18
Health Hazard Evaluation Report No.2000-0410-2891 Page 23

Table 3

Ceiling (5-minute) PBZ air sampling results for 1- and 2-BP

STN Cushion Company

Thomasville, North Carolina

HETA 2000-0410-2891

November 14, 2000

Job Title Department

Sample

Time 

(min)

Sample

Volume

(L)

Concentration, ppm

1-BP 2-BP

Sprayer Fabrication 5 1.2 151.9 1.13

Sprayer Fabrication 6 1.6 51.9 0.49

Sprayer Fabrication 6 1.5 44.3 0.59

Sprayer Fabrication 5 1.2 114.3 1.13

Sprayer Fabrication 5 1.3 70 0.81

Sprayer Fabrication 6 1.5 102.8 1.08

Sprayer Fabrication 6 1.6 48.7 0.63

Sprayer Fabrication 6 1.6 39.5 0.37

Sprayer Fabrication 6 1.6 72.2 0.8

Sprayer Fabrication 5 1.2 49.7 0.56

Sprayer Fabrication 5 1.5 67.6 0.69

Minimum Detectable Concentration (MDC) 0.12 0.12

Minimum Quantifiable Concentration (MQC) 0.5 0.37
Page 24 Health Hazard Evaluation Report No.2000-0410-2891

Table 4

Full-Shift Area Air Sampling Data for 1- and 2-Bromopropane

STN Cushion Company

Thomasville, North Carolina

HETA 2000-0410-2891

November 14, 2000

Sample Location

Sample

Time

(min)

Sample

Volume

(L)

Concentration, ppm

1-BP 2-BP

In the middle of the Saw room 480 46.3 7.7 0.2

In the middle of the Fabrication room 478 47.0 7.2 0.11

In the middle of the Poly room 474 45.9 1.7 0.05

Minimum Detectable Concentration 0.004 0.004

Minimum Quantifiable Concentration 0.02 0.01
Health Hazard Evaluation Report No.2000-0410-2891 Page 25

Table 5 – Full shift PBZ air sampling results for 1- and 2-BP

HETA 2000-0410-2891

STN Cushion Company, Thomasville, North Carolina

July 31 to August 2, 2001

Sample

location

Concentration (ppm), 8-hr TWA

Average 

1-BP 

exposure 

July 31 August 1 August 2

sample vol

(L)

1-BP 2-BP sample vol

(L)

1-BP 2-BP sample vol

(L)

1-BP 2-BP

Station #1 43.6 8.8 0.1

Station #2 43.8 15 0.2 45.8 10.6 0.1 48.3 20.7 0.1 15.4

Station #3 43.4 15.1 0.1 48.6 14.2 0.1 47.4 24.8 0.2 18

Station #4 42.7 21.1 0.2 49.2 16.3 0.2 37.3 19.9 0.2 19.1

Station #5 34.6 14.71,

2

0.2 44 16.11 0.2 46.7 23.81,2,3 0.2 18.2

Station #6 35.9 31.9 0.3 30.1 17W,1 0.1 45.9 34.9 0.4 27.9

Station #7 35 16.51,

2

0.1 44.9 17.3 0.2 47.3 15.31,2,3 0.2 16.4

Station #8 31.1 13.91 0.1 32.5 17.5 0.1 45.3 14.3 0.2 15.2

Station #9 34.3 15.11 0.2 27.8 7.7 0.1 49.3 28.43 0.3 17

Station

#10

34 11.8 0.1 42 21.81 0.2 23.7 17.82,3 0.2 17

Station

#11

33.8 15.81 0.2 44.4 29 0.2 47.4 32.71 0.3 25.8

Station

#12

34 18.9

W

0.2 45.3 17.81 0.2 46.5 24.11,3 0.2 20.2

Mean 16.6 0.2 16.8 0.1 23.3 0.1
Page 26 Health Hazard Evaluation Report No.2000-0410-2891

Recommended exposure guideline 

25 ppm

Minimum Detectable Concentration 0.003

 1 ppm

 0.003 

 0.009

1

 Stayed in Fabrication during morning break. 2 Stayed in Fabrication during lunch break.

3

 Stayed in Fabrication during afternoon break. W Station that periodically used water-based spray adhesive.
Health Hazard Evaluation Report No.2000-0410-2891 Page 27

Table 6

Short term (15 minute) PBZ air sampling results for 1- and 2-BP

HETA 2000-0410-2891

STN Cushion Company

Thomasville, North Carolina

July 31 to August 2, 2001

Sample location Sample volume (L) 1-BP, ppm 2-BP, ppm

Station #2 3 8 Trace*

Station #3 3 16 0.2

Station #5 3.2 26 0.3

Station #6 3 47 0.4

Station #7 3 31 0.3

Station #8 3 7 Trace

Station #9 3 56 0.2

Station #10 3 40 0.4

Station #11 3 0.2 Trace

Station #12 3 25 0.2

Minimum Detectable Concentration 0.05 0.04

Minimum Quantifiable Concentration 0.13 0.13 

* Trace concentrations fall between the MDC and the MQC.
Page 28 Health Hazard Evaluation Report No.2000-0410-2891

Table 7

Ceiling (5 minute) PBZ air sampling results for 1- and 2-BP

HETA 2000-0410-2891

STN Cushion Company

Thomasville, North Carolina

July 31 to August 2, 2001

Sample location Sample vol. (L) 1-BP, ppm 2-BP, ppm

Station #2 1 32 ND*

Station #3 1.1 21 ND

Station #4 1 35 0.5

Station #5 1 26 ND

Station #6 1 ND ND

Station #7 1 ND ND

Station #8 1 ND ND

Station #9 & 12** 1.1 ND ND

Station #10 1.3 29 ND

Station #11 1 38 ND

Minimum Detectable Concentration 0.14 0.12

Minimum Quantifiable Concentration 0.4 0.4

* ND—‘Not Detected’, concentrations are below the MDC. 

**Worker worked at both booths during this time.
Health Hazard Evaluation Report No.2000-0410-2891 Page 29

Table 8

Air sampling results from non-sprayers

HETA 2000-0410-2891

STN Cushion Company

Thomasville, North Carolina

July 31 to August 2, 2001

Sample type Date Location Sample vol

(L)

1-BP, ppm,

8-hr TWA

2-BP, ppm,

8-hr. TWA

PBZ 1 37102 Shipping 36.1 5.8 0.1

PBZ 37102 Tick cutting 36 5.4 0.1

PBZ 37102 Sewing 36.1 5 0.1

PBZ 37102 Pattern room 35.9 4.6 0.1

PBZ 37102 Front office 36.5 4.2 0.1

GA 2 37102 Outside on fence 19.5 0.01 ND*

GA 37102 Outside near fab. AC unit 22.6 0.01 ND

PBZ 37103 Poly cut 45.6 2.4 0.04

PBZ 37103 Feather room 11.8 1.1 0.03

GA 37103 Pattern room 48 5 0.09

PBZ 37103 Fabric cut 19.8 2 0.04

GA 37104 Fabrication doorway into

Saw room

43.4 6.1 0.1

GA 37104 Poly cut 44.9 4.1 0.1

PBZ 37104 Sewing 47.2 5.2 0.1

PBZ 37104 Poly cut 47 3.8 0.1

GA 37104 Front office 44.9 3.1 0.1

GA 37104 I-beam in Poly cut 42.4 5 0.1

Minimum Detectable Concentration 0.004 

0.003

Minimum Quantifiable Concentration 0.011 0.011

1

 PBZ—Personal Breathing Zone.

2

 GA—General Area.
Page 30 Health Hazard Evaluation Report No.2000-0410-2891

* ND—‘Not Detected’, concentrations are below the MDC. 
Health Hazard Evaluation Report No.2000-0410-2891 Page 31

Table 9

Capture velocity and exhaust flow rate for Fabrication workstations (before enclosure).

HETA 2000-0410-2891

STN Cushion Company

Thomasville, North Carolina

April 18, 2001

Workstation number Measured capture

velocity at 3 ft1

ft/min

Calculated

Flow rate

CFM2

 1 6 231

2 N/V3 283

3 24 755

4 73 1545

5 37 546

A* 14 454

6 N/V 646

7 44 917

8 31 612

9 6 615

10 24 447

11 8 527

12 30 593

B* 26 564

1

 Value for workstation 6 is measured at a distance of 18 inches above the surface of the downdraft table.

2 Cubic feet per minute.

3

 N/V—No data was available for this condition.

* These two booths removed before next evaluation, Table10.
Page 32 Health Hazard Evaluation Report No.2000-0410-2891

Table10

Average Spray Booth Ventilation Hood Face Velocity (after enclosure)

HETA 2000-0410-2891

STN Cushion Company

Thomasville, North Carolina

July 31 to August 2, 2001

Station # # measurements

used to average

Capture Velocity*

w/doors open (ft/min)

Capture Velocity w/doors

closed (ft/min)

1 & 2 28 57 70

3 20 30 50

4 20 34** 37

5 20 35 37

6 20 41 39

7 20 25 27**

8 20 17 24

9 & 10 28 26** 25

11 20 19 21

12 20 18 18

 * Measured at 3 ft from the LEV hood.

** Indicates that measurements were only taken once, rather than twice as done for the other average values.
Health Hazard Evaluation Report No.2000-0410-2891 Page 33
Page 34 Health Hazard Evaluation Report No.2000-0410-2891

Table 11

Characteristics of Study Participants Completing Questionnaire

HETA 2000-0410-2891

STN Cushion Company

Thomasville, North Carolina

July 31 to August 2, 2001

Characteristic Participants in Exposed

Group (N=12)

Participants in Comparison

Group (N=18)

# (%) Female 12 (100%) 15 (83%)

Mean Age in Years (Range) 44 (29-65) 36 (21-55)

# (%) White 8 (67%) 16 (89%)

# (%) Black 4 (33%) 2 (11%)

Mean Length of Employment at

STN in Months

 (Range)

13 (2-24) 21 (1-85)

# (%) Reporting Prescription

Medication Use 6 (50%) 7 (39%)

# (%) Reporting Exposure to

Other Substances of Concern1 2 (17%) 7 (39%)

# (%) Smoking Cigarettes2 5 (42%) 10 (56%)

1 Question asked if individual had any hobbies, household chores, part-time jobs or other activities that involve

use of arsenic, mercury, lead, cadmium, solvents, pesticides or other chemicals.

2

Individuals who responded “yes” to the question “Do you currently smoke cigarettes?”
Health Hazard Evaluation Report No.2000-0410-2891 Page 35

Table 12

Reported Symptoms and Odds Ratios Among 1-Bromopropane Exposed and Comparison Groups

HETA 2000-0410-2891

STN Cushion Company

Thomasville, North Carolina

July 31 to August 2, 2001

Symptom

# (%) of

Participants

Reporting

Symptom - 

Exposed Group

N=12

# (%) of

Participants

Reporting

Symptom - 

Comparison

Group

N=18

Odds

Ratio

95 % Confidence

Interval

Lower - Upper

Anxiety, nervousness 2 (17%) 2 (11%) 1.78 0.21 14.86

Appetite increase 0 (0%) 2 (11%) § § §

Appetite decrease 0 (0%) 0 (0%) § § §

Blurred vision 6 (50%) 1 (6%) 16.00* 1.58 162.10

Trouble concentrating 1 (8%) 0 (0%) § § §

Depression 3 (25%) 1 (6%) 6.00 0.54 67.28

Diarrhea 1 (8%) 1 (6%) 1.60 0.09 28.57

Dizziness; feeling “off

balance” 6 (50%) 1 (6%) 15.00* 1.48 152.50

Felt drunk, “high,”

“stoned” 1 (8%) 0 (0%) 1.10 0.91 1.33

Headache 7 (58%) 7 (39%) 2.00 0.45 8.96

Memory loss;

forgetfulness 2 (17%) 2 (11%) 1.50 0.18 12.46

Nausea 4 (33%) 2 (11%) 3.75 0.56 25.12

Numbness or “pins

and needles” feeling in

hands

3 (25%) 3 (17%) 1.67 0.28 10.09

Numbness or “pins

and needles” feeling in

feet

4 (33%) 1 (6%) 9.71 0.92 103.04

Sleeping too much 2 (17%) 1 (6%) 3.78 0.30 47.56

Trouble falling asleep

or staying asleep 5 (42%) 3 (17%) 4.17 0.75 23.18

Tremor or shakiness 2 (17%) 1 (6%) 4.25 0.33 54.07

Weakness/clumsiness

in hands 1 (8%) 2 (11%) 0.80 0.06 10.01

Problems with hand

writing 1 (8%) 1 (6%) 1.70 0.10 30.28

Weakness in arms 3 (25%) 3 (17%) 1.88 0.31 11.52

Weakness in feet 2 (17%) 0 (0%) 1.22 0.93 1.62

Weakness in legs 3 (25%) 1 (6%) 6.38 0.57 71.27

Walking problems 1 (8%) 0 (0%) 1.10 0.91 1.33

Weight loss 1 (8%) 1 (6%) 1.70 0.10 30.28

§ One or more of the contingency table counts was equal to zero.
Page 36 Health Hazard Evaluation Report No.2000-0410-2891

* Asterisks indicate a significant difference from the comparison group (*p<0.05.)
Health Hazard Evaluation Report No.2000-0410-2891 Page 37

Table 13

Urine Bromine Analysis Of 1-Bromopropane Exposed and Comparison Groups 

HETA 2000-0410-2891

STN Cushion Company

Thomasville, North Carolina

July 31 to August 2, 2001

Measure (Matched

Pair) Population NumberSubjects

Geometric

Mean1

Minimum

Value 1

Maximum

Value 1

Probability

(p value)

Start-of-week Urine

Bromine

Concentration

Exposed 7 6.4 1.8 14.0 0.005*

Comparison 10 1.9 1 3.5

End-of-week Urine

Bromine

Concentration

Exposed 7 7.7 2.5 38.0 0.003*

Comparison 12 2 0.8 6.2

Post Minus PreExposure

Concentration

(Difference)

Exposed 6 -0.42 -3 3.1 0.7103

Comparison 10 0.12-1.3 3.6 0.9173

1 Concentration is reported in milligrams per liter.

2

 Value is arithmetic mean (Geometric mean can not evaluate negative numeric data.)

3 Test Value = 0, Ho

: mean of sample = 0 (For exposed group expect mean to be > 0, for comparison group expect mean to be = 0.)

* Asterisks indicate a significant difference from the comparison group (*p<0.05.)
Page 38 Health Hazard Evaluation Report No.2000-0410-2891

Table 14

Neurobehavioral Test Parameter Analysis Of 1-Bromopropane Exposed and Comparison Groups

HETA 2000-0410-2891

STN Cushion Company

Thomasville, North Carolina

July 31 to August 2, 2001

Measure Population Number

Subjects Mean 

Minimum

Value

Maximum

Value

Probability

(p value)

Tremor Pen Right – Intensity

(meter/second2)

Exposed 12 0.14 0.10 0.22 0.033*

Comparison 18 0.11 0.06 0.16

Tremor Pen Right –

Frequency (Hertz)

Exposed 12 7.5 5.7 8.8 0.001*

Comparison 18 6.3 4.5 8.8

Tremor Pen Right –

Harmonic Index

Exposed 12 0.92 0.85 0.99 0.717

Comparison 18 0.92 0.85 0.98

Tremor Pen Left – Intensity

(meter/second2)

Exposed 12 0.11 0.07 0.19 0.241

Comparison 18 0.10 0.06 0.16

Tremor Pen Left – Frequency

(Hertz)

Exposed 12 6.5 4.4 9.2 0.882

Comparison 18 6.4 4.7 8.4

Tremor Pen Left – Harmonic

Index

Exposed 12 0.90 0.87 0.95 0.100

Comparison 18 0.88 0.79 0.98

Reaction Time – Mean Exposed 12 0.264 0.183 0.354 0.415

Comparison 18 0.248 0.189 0.310

Reaction Time – 

Standard Deviation

Exposed 12 0.048 0.020 0.090 0.917

Comparison 18 0.049 0.029 0.105

Slow RF1 Finger Tap – Mean Exposed 12 -0.0563

-0.158 0.022 0.253

Comparison 18 -0.0713-0.164 0.027

Slow RF1 Finger Tap – 

Standard Deviation

Exposed 12 0.059 0.018 0.114 0.015*

Comparison 18 0.044 0.029 0.096
Health Hazard Evaluation Report No.2000-0410-2891 Page 39

Table 14 (Continued)

Neurobehavioral Test Parameter Analysis Of 1-Bromopropane Exposed and Comparison Groups

HETA 2000-0410-2891

STN Cushion Company

Thomasville, North Carolina

July 31 to August 2, 2001

Measure Population Number

Subjects Mean MinimumValue

Maximum

Value Probability

Fast RF1 Finger Tap – Mean Exposed 12 -0.0603

-0.154 -0.001 0.755

Comparison 18 -0.0513-0.139 0.014

Fast RF1 Finger Tap – 

Standard Deviation

Exposed 12 0.047 0.008 0.115 0.062

Comparison 18 0.029 0.016 0.131

Maximum Frequency Finger

Tap

Exposed 12 5.0 1.6 7.5 0.819

Comparison 18 5.2 3.2 7.5

Slow P/S2 RF1 – Mean Exposed 12 -0.0653

-0.138 0.004 0.692

Comparison 18 -0.0663-0.149 0.077

Slow P/S2 RF1 – 

Standard Deviation

Exposed 12 0.066 0.032 0.155 0.602

Comparison 18 0.056 0.032 0.136

Maximum Frequency P/S2 Exposed 12 3.7 2.5 6.0 0.491

Comparison 18 3.2 1.0 4.9

1 Rhythmic Frequency.

2 Pronation/Supination.

3 Value is arithmetic mean (Geometric mean can not evaluate negative numeric data.)

* Asterisks indicate a significant difference from the comparison group (*p<0.05.)
Page 40 Health Hazard Evaluation Report No.2000-0410-2891

APPENDIX

Brominated Solvents

Background and Significance

In 1990 the Clean Air Act(CAA) was amended

to include more stringent provisions for the

protectionofstratospheric ozone and the phaseout of several ozone-depleting substances under

Title VI of the law.

1

 The law targeted the

complete phase-out of several substances

including chlorofluorocarbons,

hydrochlorofluorocarbons, and methyl

chloroform, each of which was being used by

industry at that time. Industrial applications of

these substances included non-aerosol solvent

cleaning, adhesive coatings applications, and

solvent applications.2 The CAA amendment

provisions were in part enacted to abide by the

terms of a United Nations (UN) international

agreement, The Montreal Protocol on

Substances that Deplete the Ozone Layer

adoptedin1987, whichcommitted to reduce and

eventually eliminate the use of ozone-depleting

substances. As a result, several countries

discontinuedand prohibited further use ofozonedepleting substances.3

 Under Section612 ofthe

CAA, ozone-depleting substances were to be

replaced withalternative substancesorprocesses

that reduced the risks to human health and the

environment.1 To fulfill the law’s requirement, the

EnvironmentalProtectionAgency(EPA)initiated

the Significant New Alternatives Policy (SNAP)

programintended to approve safe alternativesfor

ozone-depleting substances.4

The solvents 1-bromopropane (1-BP) and 2-

bromopropane (2-BP) were introduced into

workplaces around the world as substitutes for

ozone-depleting substancesfollowing initiationof

the 1987 UN international treaty. The physical

properties of these two solvents, including high

volatility and low flammability, were seen as

favorable characteristics for a non-aerosol

solvent. Due to photochemical breakdown, the

solvents have a relatively short atmospheric halflife (17.5 to 24 days), possibly decreasing their

ozone-damaging capacity.

5,6

 

At the present time, 2-BP is not produced for

commercial use in the United States (U.S.).

However, 1-BP is produced and commercially

available in the U.S. The purityof1-BP is listed

as 99% inMaterial Safety Data Sheets (MSDS)

fromtwo laboratoryreagent manufacturers.7,8 A

1999 Occupational Safety and Health

Administration (OSHA) analysis of several

commercial samples of 1-BP found them to

contain 2-BP in concentrations ranging from 0.1

to 0.2 percent.9 A voluntary consensus standard

(D6368-00) published by the American Society

For Testing and Materials has since been

released covering vapor degreasing and general

grade 1-BP and specifies that the content of 2-

BP in these solvent grades remain below 0.1

percent.10 Currently only 1-BP is being reviewed

under the SNAP program as a potential

alternative to ozone-depleting substances.2 At

thistime, the EPA has not disapproved the use of

1-BP, so it may be used for any purpose in the

U.S. (while 2-BP may not).9

Review of Literature—

1-Bromopropane

Animal exposure studies have demonstrated

reproductive toxicity for both male and female

ratswhenexposed to concentrations greaterthan

or equal to 200 parts per million (ppm) of

1-BP.

11,12 Two studies noted mild hepatic
Health Hazard Evaluation Report No.2000-0410-2891 Page 41

changes in rats exposed to greater than or equal

to 800 ppm of 1-BP; these changes were

considered adaptive and reversible due to the

absence of other signs of hepatotoxicity.

11,13,14

Although 2-BP exposure has been associated

with pancytopenia, animal studies evaluating

potentialhematopoietic effects of1-BP exposure

have yielded no firm conclusions. The median

lethal inhalation concentration of 1-BP for

Sprague-Dawley rats has been estimated to be

14,374 ppm.13

Four studies have demonstrated some form of

neurotoxicity in rats exposed to 1-BP. All

studiesinvolved exposure concentrations greater

than or equal to 800 ppm. Three of the studies

demonstrated decreased peripheral nerve

functioning by electrophysiologic testing and

morphologic or histopathologic abnormalities of

central and peripheral nerves.15,16,17 Two of

these three studies also demonstrated a

prominent weakness of the hind limbs following

exposure.15,17 A fourth study demonstrated

decreased peripheral nerve functioning by

electrophysiologic testing alone.18 One of the five

studies established that the muscle weakness and

decreased electrophysiologic findings were both

dependent on concentration and length of

exposure period.17 This same study and one

other came to the conclusion that 1-BP was a

more potent neurotoxicant than 2-BP; another

study that evaluated the neurotoxicity of both 1-

BP and 2-BP was unable to conclude that 1-BP

was a more potent neurotoxicant.15,18 

A total of four persons with health effects

considered related to 1-BP exposure have been

described in two published case reports. The

first case report concerned a 19-year-old male

working as a metal‘stripper’.19 He was exposed

on a daily basis over a two-month period to an

industrial solvent (containing greater than 95.5

percent 1-BP byweight) used for degreasingand

cleaning. His right hand was most commonly

exposed to the solvent. The air concentrationof

1-BP and type of ventilation were not discussed

in the article. Presenting symptoms included

“numbnessand mild but progressive weakness of

the proximal lower extremities and the right

hand... transient dysphagia and urinary

difficulties.”19 The physical findings, magnetic

resonance imaging (MRI) of the brain, and

electromyography (EMG)findingssupported the

diagnosis of a “primary demyelinating condition,

predominantly affecting the lower extremities, in

the distribution of an acquired neuropathy, but

with evidence of central nervous system

involvement as well.” The EMG did not indicate

any evidence of muscle denervation. The

individualdid demonstrateimprovementfollowing

removalfromexposure,butwaslost to follow-up

before it was determined if the health effects

would fully resolve.

The second case report concernedthreefemales,

ages 35, 30, and 50, each working at cushion

manufacturing companies in North Carolina.20

The workerssprayed glue (containing55 percent

1-BP as the base solvent) with a spray gun onto

polyurethane foampieces. A total of 15 workers

performed this process in an open work area.

Exhaust ventilationprovided at each workstation

was operated intermittently and workers wore

latexglovesfor dermalexposure protection. The

first worker’s symptoms developed one year

following the replacement of a dichloromethanebased glue with the 1-BP-based glue. The

remaining two workers developed symptoms six

months and two months, respectively, following

commencement of their employment in the

exposure area. Airborne exposures of the three

workers were notwell described; the case report
Page 42 Health Hazard Evaluation Report No.2000-0410-2891

did state that one worker was found to have

time-weighted average (TWA) exposures of

between 60 to 261 ppm of 1-BP over several

days of monitoring 5 months aftersymptoms had

started. 

“The three workers showed the common

symptoms of staggering, numbness and

paresthesia/dysesthesia with a similar distribution

in their feet, legs, thighs, lower back and hips as

well as a remarkable decrease invibrationsense,

along with various symptoms of the central

nervous system and autonomic symptoms.”20

Other symptoms experienced by the workers

includedtemporarymenstrualcycle disruptionfor

two of the three women, diarrhea, abnormal

sweating, and urinary incontinence. The

researchers concluded that 1-BP likely caused

the peripheraland centralnervous systemdeficits

and that the other noted symptoms were likely

relatedtoautonomic systemdisruptionsecondary

to 1-BP exposure. The study did not indicate if

the symptoms improved or resolved upon

removal from exposure.

Limited information is available from an

unpublished abstract submitted at the 2002

Annual Meeting of the Society of Toxicology

regarding the only 1-BP human health effect

study performed to date.21 The study evaluated

a group of 25 female workers, exposed to low

levels of 1-BP, for neurological effects,

comparing them to a group of 27 unexposed

controls. Neurobehavioral and

electrophysiological assessments of nerve

function were performed on both groups.

Because of the limited nature of the information

presented in this abstract, it is difficult to draw

conclusions from this study.

Review of Literature— 

2-Bromopropane

Following report of the occurrence ofsecondary

amenorrhea among female workers in a tactile

switch assembly section of a South Korean

factory, two studies were performed to evaluate

the health effects of workers in the factory.

22,23

The studies found background area air sample

concentrations of2-BP to range from9.2 to 19.6

ppm. The concentration of 2-BP detected during

a short-termsample inside the hood of a cleaning

bathwas 4,140.7 ppm. One study theorized that

workers might be exposed to higher

concentrations of 2-BP forshort periods of time

when performing operations at the cleaning

bath.22 The other study theorized that because

therewere two uncovered 2-BP baths inthe area

and ventilated air was recirculated, 2-BP

concentrations were routinely elevated in the

work area.23 Both studies concluded that 2-BP

exposure was the probable cause of the health

effects(ovarianfailure infemales, azoospermia or

oligospermia in males, and pancytopenia) noted

in the exposed workers. 

Following these reports,severalstudies designed

to evaluate health effects associated with

exposure of rats to 2-BP were initiated; these

studies demonstrated ovarian, testicular, and

hematopoietic dysfunctionbeginning at exposure

levels of greater than 300 ppm or 250 milligram

per kilogram (mg/kg).24,25,26,27,28 Two studies

recently demonstrated peripheral neurotoxic

changes and peripheral neuropathy in rats

exposed to 1,000 ppmof2-BP.

18,29 The median

lethal inhalation concentration of 2-BP for the

Sprague-Dawley rat has been estimated to be

31,171 ppm.30 
Health Hazard Evaluation Report No.2000-0410-2891 Page 43

1. United States Code [1990]. 42 USC

7401 et. seq. Washington, DC: U.S. Government

Printing Office.

2. 65 Federal Register 78977 [2000].

Environmental Protection Agency: Protection of

stratospheric ozone: Notice 14 for significant new

alternatives policy program; notice of

acceptability; request for information.

3. United Nations Environmental Programme

[2000]. Ozone Treaties.

[http://www.unep.ch/ozone/treaties.shtml]. Date

accessed: May 5, 2002.

4. 58 Fed. Reg. 54892 [1993]. Environmental

Protection Agency: Protection of stratospheric

ozone; final rule.

5. Donaghy T, Shanahan I, Hande M, Fitzpatrick

S [1993]. Rate constants and atmospheric

lifetimes for the reactions of OH radicals and Cl

atoms with haloalkanes. Int J Chem Kinet

25(4):273–84.

6. Meylan WM, Howard PH [1993]. Computer

estimation of the atmospheric gas-phase reaction

rate of organic compounds with hydroxyl radicals

and ozone. Chemosphere 26(12):2293–2300.

7. Aldrich Chemical Company. Material safety

data sheet for 1-bromopropane, 99%. May 2002.

8. Acros Organics N.V. Material safety data

sheet for 1-bromopropane, 99%. May 2002.

9. OSHA [1999]. Nomination of 1-

bromopropane (1-BP) and 2-bromopropane (2-

BP) for testing by the National Toxicology

Program. Washington, DC: Department of Labor,

Directorate of Health Standards Programs, U.S.

Occupational Safety and Health Administration,

DOL (OSHA).

10. ASTM [2001]. D6368-00 Standard

specification for vapor-degreasing grade and

general grade normal-propyl bromide. West

One study has been conducted to evaluate the

health effects of 2-BP on employees working at

a 2-BP manufacturing plant. During the study,

conducted in 1996, worker breathing zone

exposure concentrations ranged from 0.80 to

16.18 ppm as an 8-hour TWA. The study

included worker interviews, medical

examinations,and specific testing ofreproductive

and hematological indices. “No severe cases of

reproductive or hematopoietic disorders were

found at (exposures) less than 10 ppm (TWA),

but a possible adverse effectof2-bromopropane

on hematopoiesis could not be disproved.”31

1-Bromopropane Biomarker of

Exposure

A study has demonstrated that among seven

different solvents, 1-BP wasthe only solvent that

significantly (p < 0.01) influenced the

concentrationof1-BP and bromine inthe urine of

exposed subjects, and thus eithermeasure canbe

used as a biomarker of exposure.32 In that study,

1-BP concentrationinthe urine was shown to be

more highly correlated to the airborne 1-BP

exposure(p < 0.01, r = 0.952) thanwas bromine

concentration in the urine (p < 0.01, r = 0.738).

However, urinary 1-BP detection requires gas

chromatography-mass spectrometry (GCMS)

instrumentation and the specimen must be

immediately analyzed after collection. Most

clinical laboratories can perform bromine

detection, and analysis may be delayed without

serious degradation of specimen quality. Cost

constraints would be the main reason why

bromine analysis might be chosen over GCMS

analysis in a study.

Appendix References
Page 44 Health Hazard Evaluation Report No.2000-0410-2891

Conshohocken, PA: American Society for Testing

Materials.

11. Ichihara G, Yu X, Kitoh J, Asaeda N,

Kumazawa T, Iwai H, Shibata E, Yamada T,

Wang H, Xie Z, Maeda K, Tsukamura H,

Takeuchi Y [2000]. Reproductive toxicity of 1-

bromopropane, a newly introduced alternative to

ozone layer depleting solvents, in male rats.

Toxicological Sciences 54:416–423.

12. Stump D [2001]. An inhlation two-generation

reproductive toxicity study of 1-bromopropane in

rats. Study No. WIL-380001. 

Ashland, OH: WIL Research Laboratories.

Unpublished. (Study sponsored by Brominated

Solvents Consortium [BSCO]).

13. Kim HY, Chung YH, Jeong JH, Lee YM, Sur

GS, Kang JK [1999]. Acute and repeated

inhalation toxicity of 1-bromopropane in SD rats.

J Occup Health 41:121–128.

14. NTP [2002]. NTP-CERHR expert panel

report on the reproductive and developmental

toxcity of 1-bromopropane. Washington, DC:

U.S. Department of Health and Human Services,

National Institutes of Health, National Institute of

Environmental Health Sciences, National

Toxicology Program, DHHS (NTP) Publication

No. NTP-CERHR-1-BP-02.

15. Yu X, Ichihara G, Kitoh J, Xie Z, Shibata E,

Kamijima M, Takeuchi Y [2001]. Neurotoxicity

of 2-bromopropane and 1-bromopropane,

alternative solvents for chlorofluorocarbons.

Environmental Research 85(1):48–52.

16. Wang H, Ichihara G, Ito H, Kato K, Kitoh J,

Yamada T, Yu X, Tsuboi S, Moriyama Y,

Sakatani R, Shibata E, Kamijima M, Itohara S,

Takeuchi Y [2002]. Biochemical changes in the

central nervous system of rats exposed to 1-

bromopropane for seven days. Toxicological

Sciences 67:114–120.

17. Ichihara G, Kitoh J, Yu X, Aseda N, Iwai H,

Kumazawa T, Shibata E, Yamada T, Wang H, Xei

Z, Takeuchi Y [2000]. 1-bromopropane, an

alternative to ozone layer depleting solvents, is

dose-dependently neurotoxic to rats in long-term

inhalation exposure. Toxicological Sciences

55:116–123.

18. Zhao W, Aoki K, Xie T, Misumi J [1999].

Electrophysiological changes induced by different

doses of 1-bromopropane and 2-bromopropane. J

Occup Health 41:1–7.

19. Sclar G [1999]. Encephalomyeloradiculoneuropathy following exposure to an 

industrial solvent. Clinical Neurology and

Neurosurgery 101:199–202.

20. Ichihara G, Miller JK, Ziolkowska A, Itohara

S, Takeuchi Y [2002]. Neurological disorders in

three workers exposed to 1-bromopropane.

J Occup Health 44:1–7.

21. Ichihara G, Li W, Shibata E, Ding X,

Kamijima M, Wang H, Liang Y, Peng S, Itohara

S, Fan Q, Zhang Y, Zhong W, Wu X, Valentine

WM, Takeuchi Y [2002]. Neurological

abnormality in workers of 1-bromopropane factory

[Abstract]. Presented at the 41st Annual Meeting

of the Society of Toxicology, Nashville, TN,

March 17–21.

22. Kim Y, Jung K, Hwang T, Jung G, Kim H,

Park H, Kim J, Park J, Park D, Park S, Choi K,

Moon Y [1996]. Hematopoietic and reproductive

hazards of Korean electronic workers exposed to

solvents containing 2-bromopropane. Scand J

Work Environ Health 22:387–391.

23. Park J, Kim Y, Park DW, Choi KS, Park S,

Moon Y [1997]. An outbreak of hematopoetic

and reproductive disorders due to solvents

containing 2-bromopropane in an electronic
Health Hazard Evaluation Report No.2000-0410-2891 Page 45

factory, South Korea: epidemiological survey.

J Occup Health 39:138–143.

24. Kamijima M, Ichihara G, Yu X, Kitoh J,

Tsukamura H, Maeda K, Yu X, Xie Z, Nakajima

T, Asaeda N, Hisanaga N, Takeuchi Y [1997].

Ovarian toxicity of 2-bromopropane in the nonpregnant female rat. J Occup Health 39:144–149.

25. Kamijima M, Ichihara G, Yu X, Xie Z, Kitoh

J, Tsukamura H, Maeda K, Nakajima T, Asaeda

N, Hisanaga N, Takeuchi Y [1997]. Disruption in

ovarian cyclicity due to 2-bromopropane in the rat.

J Occup Health 39:3–4.

26. Lim CH, Maeng SH, Lee JY, Chung YH,

Kim TG, Park JH, Moon YH, Yu IJ [1997].

Effects of 2-bromopropane on the female

reproductive function in Sprague-Dawley rats.

Industrial Health 35:278–284.

27. Yu IJ, Chung YH, Lim CH, Maeng SH, Lee

JY, Kim HY, Lee SJ, Kim CH, Kim TG, Park JS,

Moon YH [1997]. Reproductive toxicity of 2-

bromopropane in Sprague-Dawley rats. Scand J

Work Environ Health 23:281–288.

28. Ichihara G, Asaeda N, Kumazawa T,

Tagawa Y, Kamajima M, Yu X, Kondo H,

Nakajima T, Kitoh J, Yu IJ, Moon YH, Hisanaga

N, Takeuchi Y [1997]. Testicular and

hematopoietic toxicity of 2-bromopropane, a

substitute for ozone layer-depleting

chlorofluorocarbons. J Occup Health 39:57–63.

29. Yu X, Ichihara G, Xie Z, Shibata E, Kamijima

M, Asaeda N, Hisanaga N, Takeuchi Y [1999].

Effect of inhalation exposure to 2-bromopropane

on the nervous system in rats. Toxicology

135:87–93.

30. Kim HY, Chung YH, Yi KH, Kim JG, Yu IJ

[1996]. LC50 of 2-bromopropane. Industrial

Health 34:403–407.

31. Ichihara G, Ding X, Yu X, Wu X, Kamijima

M, Peng S, Jiang X, Takeuchi Y [1999].

Occupational health survey on workers exposed to

2-bromopropane at low concentrations. Am J Ind

Med 35:523–531.

32. Kawai T, Takeuchi Y, Moriyama Y,

Sakamoto K, Zhang ZW, Higashikawa K, Ikeda

M [2001]. Biological monitoring of occupational

exposure to 1-bromopropane by means of

urinalysis for 1-bromopropane and bromide ion.

Biomarkers 6(5):303–312.
DEPARTMENT OF HEALTH AND HUMAN SERVICES

Centers for Disease Control and Prevention

National Institute for Occupational Safety and Health

4676 Columbia Parkway

Cincinnati, OH 45226-1998

OFFICIAL BUSINESS

Penalty for private use $300

Delivering on the Nation's promise: 

Safety and Health at work for all people

through research and prevention

To receive NIOSH documents or information

about occupational Safety and Health topics

contact NIOSH at:

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

1-513-533-8573 E-mail: pubstaft@cdc.gov

or visit the NIOSH web site at:

www.cdc.gov/niosh/homepage.html

S A F E R • H E A L T H I E R • P E O P L ETM