December 5, 2008 / Vol. 57 No.48 

full issue available at: http://www.cdc.gov/mmwr/PDF/wk/mm5748.pdf 

(This article may be found on pages 1300 - 1302 of the full issue) 

Neurologic Illness Associated with 

Occupational Exposure to the Solvent 1-

Bromopropane --- New Jersey and 

Pennsylvania, 2007--2008 

1-Bromopropane (1-BP) (n-propyl bromide) is a solvent increasingly used as a substitute 

for ozone-depleting chloro-fluorocarbons and similar regulated compounds. 1-BP is used 

in vapor and immersion degreasing operations and other manufacturing processes, and as 

a solvent in industries using aerosol-applied adhesives. In some states, 1-BP is used as a 

solvent in dry cleaning because of restrictions on use of perchloroethylene 

(tetrachloroethylene), a possible human carcinogen (1). Published studies of workers 

exposed to 1-BP have raised concerns about occupational health risks associated with 

exposure (2--5). This report describes two cases involving workers exposed to 1-BP and 

diagnosed with clinical manifestations of neurotoxicity. The cases, when coupled with 

previously reported studies of workers exposed to 1-BP, illustrate potential health risks of 

1-BP exposure. Clinicians and public health professionals should be alert to potential 

health effects among workers exposed to 1-BP, particularly in dry cleaning and other 

workplaces where 1-BP use might be increasing, and effective control methods to limit 

exposure to 1-BP should be implemented at worksites. 

Both cases involved neurotoxic effects that likely resulted from occupational exposure to 

1-BP in the electronics and dry cleaning industries. The cases were reported to regional 

poison control centers in Pennsylvania (2007) and New Jersey (2008) by attending 

physicians who treated the affected workers. The cases were investigated by federal and 
state health agencies, and more in-depth investigations of the New Jersey case currently 

are being conducted by the New Jersey Department of Health and Senior Services and 

CDC. 

Case 1. In 2007, a male aged 50 years visited an emergency department in Pennsylvania 

with a history of confusion, dysarthria, dizziness, paresthesias, and ataxia for 24--48 

hours. The patient had worked for 8 years at an electronics plant in Pennsylvania, where 

for 3 years 1-BP had been used to clean circuit boards by vapor and immersion 

degreasing. His duties at the plant included mechanically submerging and spraying circuit 

boards with 1-BP, and maintenance (draining, cleaning, and charging) of the bath tank. 

The patient typically did not use personal protective equipment (PPE), and ventilation 

was reported by the patient to be poor within the process room. Neurologic examination 

revealed that the patient was alert but had slowed mental activity and mild confusion. His 

cranial nerve function and motor strength were intact, but his gait was wide based and 

ataxic, and a Romberg's test was positive. Serum laboratory results were notable for an 

anion gap of -31 mmol/L (normal range: 5--17 mmol/L) and a chloride concentration of 

146 mmol/L (normal range: 101--111 mmol/L). The patient was hospitalized. Mild 

sensory peripheral neuropathy was detected by electromyogram in his upper and lower 

extremities. 

One week after the patient went to the emergency department, the Occupational Safety 

and Health Administration (OSHA) evaluated his workplace and found a 1-BP 

concentration of 178 ppm by short-term area air sampling. Two weeks after his initial 

visit to the emergency department, the patient's serum bromide concentration was 48 

mg/dL (normal range: 0--10 mg/dL). His peripheral neuropathy and ataxia persisted 1 

year after the initial visit. The patient also reported having trouble maintaining mental 

focus and stopped working at the electronic plant because of continuing medical 

problems. 

Case 2. A previously healthy male aged 43 years visited his primary-care physician in 

New Jersey in February 2008 with a history of headache, nausea, dizziness, and malaise, 

which began after he had begun using 1-BP in his dry cleaning facility. Six weeks earlier, 

the patient had switched from using perchloroethylene to DrySolvTM (Enviro Tech 

International, Melrose Park, Illinois) (>95% by weight 1-BP) as the solvent in his dry 

cleaning machine (7). The patient also used DrySolv as a cleaner to prepare the dry 

cleaning machine for use. In early February 2008, he manually charged the machine 

using 50--60 gallons of the solvent and did not use PPE. The patient then began using 

DrySolv in the daily operation of the dry cleaning machine. During the next 2 days, he 

reported unusual fatigue and headaches and developed arthralgias, visual disturbances 

(difficulty focusing), paresthesias, and muscular twitching. 

The patient was referred by his personal physician to an emergency department, where 

physical examination and computed tomography of his head were normal, except for a 

slight tremor in his upper extremities. Tests of the patient's serum revealed an anion gap 

and chloride concentration within normal ranges. A site visit to the dry cleaning facility 

in April 2008 by the New Jersey Department of Health and Senior Services revealed 
background and high peak concentrations (75 to 250 times background levels) of 1-BP 

during the handling of clothes. The patient continued to use 1-BP in the dry cleaning 

machine but adjusted temperature settings on the machine to account for the physical 

properties of 1-BP, improved his use of ventilation, and began using PPE. 

Reported by: J Perrone, MD, Univ of Pennsylvania School of Medicine. SM Marcus, 

MD, Univ of Medicine and Dentistry of New Jersey and New Jersey Poison Information 

and Education System; JD Blando, PhD, D Schill, MS, New Jersey Dept of Health and 

Senior Svcs. D Trout, MD, P Schulte, PhD, CL Geraci, PhD, GS Dotson, PhD, K Hanley, 

MSPH, KR Mead, PhD, DVL Myers, PhD, C Curran, PhD, National Institute for 

Occupational Safety and Health, CDC. 

Editorial Note: 

1-BP has received increased global attention since the 1990s as a potential alternative for 

ozone-depleting chlorofluorocarbons and similar regulated compounds. Since its 

introduction within the United States, 1-BP has been applied as a solvent in many 

industrial processes, including vapor degreasing, foam cushion manufacturing, and dry 

cleaning. The incidence of 1-BP toxicity is unknown, and the signs and symptoms are not 

described fully. In this report, case 1 demonstrated severe neurologic illness in a worker 

in the electronics industry using 1-BP as a cleaning solvent. The elevated serum bromide 

concentration and negative anion gap in a worker with neurologic abnormalities exposed 

to 1-BP provides strong evidence of occupational 1-BP toxicity. Although bromide levels 

were not measured in case 2, the patient's clinical presentation and course, and his 

exposure to 1-BP, strongly favor the conclusion that his illness was caused by 1-BP. 

However, the exact etiology of the neurologic illnesses of the two workers remains 

unclear and nonwork-related factors potentially contributing to the illnesses are not fully 

characterized. Additionally, personal exposure information was not available for these 

workers to help establish their workplace exposures to 1-BP or to other potential 

workplace hazards. 

CDC does not have a recommended exposure limit for 1-BP, nor does OSHA have a 

permissible exposure limit. Manufacturers of 1-BP and professional organizations, such 

as the American Conference of Governmental Industrial Hygienists, have recommended 

occupational exposure limits ranging from 10 ppm to 100 ppm as an 8-hour timeweighted average (6). On the basis of limited exposure and human health effects data, the 

National Toxicology Program concluded that exposure to 1-BP is toxic to the 

developmental and reproductive health of animals (8). Animal toxicity studies with 1-BP 

and human case reports of occupational exposures to 1-BP have raised concerns that 

exposure to 1-BP might cause reproductive and neurologic effects (2--6). Workers 

exposed to 1-BP vapors from spray adhesives at two seat-cushion--manufacturing 

facilities were found to have severe neurologic illnesses (4,5). CDC evaluated workers at 

one of those facilities and found nonspecific acute effects (e.g., headache and feeling 

drunk) possibly associated with central nervous system responses to 1-BP exposure (2). 
In accordance with its Significant New Alternatives Program, the Environmental 

Protection Agency (EPA) has reviewed available scientific literature on 1-BP and 

promulgated a final rule to accept 1-BP as an alternative for ozone-depleting solvents in 

the solvent cleaning sector.* EPA also published a proposed rule not to accept 1-BP for 

use as an aerosol solvent vehicle for adhesives because of higher exposures and the 

potential for adverse health effects to workers in these settings.†

 These new rules do not 

apply to dry cleaning. 

Case 2 likely represents a sentinel case of neurologic toxicity in the dry cleaning industry, 

and additional cases could occur as dry cleaners switch from perchloroethylene use to 1-

BP. The U.S. dry cleaning and laundry industry employs an estimated 110,000 persons at 

approximately 30,000 establishments and is one of the largest industry sectors 

characterized by small businesses with fewer than 10 employees. In recent years, an 

estimated 85%--90% of the dry cleaning industry has used perchloroethylene as a 

solvent. In response to environmental and health concerns, certain states, including 

California and New Jersey (9,10), have passed or proposed legislation to eliminate use of 

perchloroethylene as the primary solvent in the dry cleaning industry. To use 1-BP as an 

alternative solvent, dry cleaning businesses must modify existing equipment to adjust 

heating/drying cycles, upgrade solvent vapor control systems, replace natural rubber 

seals, and provide adequate exhaust ventilation. Manufacturer literature on the use of 

DrySolv recommends wearing a full-facepiece organic vapor respirator if ventilation is 

inadequate, and chemical-resistant gloves for skin protection (7). Previous CDC research 

and communication efforts have emphasized application of a hierarchy of controls (e.g., 

engineering controls and work practices) for reducing worker exposures to 

perchloroethylene.§

 Similar controls should be used within the dry cleaning industry to 

limit worker exposure to 1-BP. 

Clinicians and public health officials should be alert to potential adverse health effects 

from exposures to 1-BP in industries where such use might increase, such as the dry 

cleaning industry, and in workplaces where 1-BP use might be more established. A 

thorough occupational history always should be part of the clinical evaluation of persons 

who have unexplained or onset of nonspecific neurologic symptoms. Exposure to 

electronics cleaning solvents or dry cleaning solvents should prompt a more through 

inquiry concerning exposure to 1-BP. In the evaluation of a worker with occupational 

exposure to 1-BP and neurologic abnormalities, diagnosis of 1-BP poisoning is suggested 

by an elevated urinary or serum bromide concentration and a negative serum anion gap. 

Findings of potential 1-BP poisoning in a potentially exposed worker should prompt 

removal of the worker from the exposure while an evaluation of workplace exposures is 

conducted by a qualified professional. 

Acknowledgment 

The findings in this report are based, in part, on contributions by JB Nemhauser, MD, 

National Center for Environmental Health, CDC. 

References 
1. Drycleaning and Laundry Institute. A DLI white paper: key information on 

industry solvents. Laurel, MD: Drycleaning and Laundry Institute; 2007. 

Available at 

http://www.startadrycleaners.com/docs2008/dli%20white%20paper.final.pdf. 

2. CDC. Health hazard evaluation report: Marx Industries, Inc. Cincinnati, OH: US 

Department of Health and Human Services, Public Health Service, CDC, National 

Institute for Occupational Safety and Health; 2003. HETA 99-0260-2906. 

Available at http://www.cdc.gov/niosh/hhe/reports/pdfs/1999-0260-2906.pdf. 

3. Ichihara G. Neuro-reproductive toxicities of 1-bromopropane and 2-

bromopropane. Int Arch Occup Environ Health 2005;78:79--96. 

4. Raymond LW, Ford MD. Severe illness in furniture makers using a new glue: 1-

bromopropane toxicity confounded by arsenic. J Occup Environ Med 

2007;49:1009--19. 

5. Majersik JJ, Caravati EM, Steffens JD. Severe neurotoxicity associated with 

exposure to the solvent 1-bromopropane (n-propyl bromide). Clin Toxicol 

2007;45:270--6. 

6. Hanley KW, Petersen M, Curwin BD, Sanderson WT. Urinary bromide and 

breathing zone concentrations of 1-bromopropane from workers exposed to 

flexible foam spray adhesives. Ann Occup Hyg 2006;50:599--607. 

7. Dry Cleaning Technologies. Material safety data sheet for DrySolv. Melrose Park, 

IL: Enviro Tech International; 2008. Available at 

http://www.dctco.com/drysolv_msds.pdf. 

8. National Toxicology Program-Center for the Evaluation of Risks to Human 

Reproduction. NTP-CERHR expert panel report on the reproductive and 

developmental toxicity of 1-bromopropane. Reproduc Toxicol 2004;18:157--88. 

9. California Environmental Protection Agency. Dry cleaning alternative solvents: 

health and environmental impacts. Sacramento, CA: California Environmental 

Protection Agency, Air Resources Board; 2008. Available at 

http://www.arb.ca.gov/toxics/dryclean/alternativesolvts_e.pdf. 

10. New Jersey Department of Environmental Protection. Control and prohibition of 

air pollution by toxic substances. Trenton, NJ: New Jersey Department of 

Environmental Protection; 2007. Available at 

http://www.nj.gov/dep/rules/proposals/121707b.pdf. 

* Environmental Protection Agency. 40 CFR part 82. Protection of stratospheric ozone: listing of 

substitutes for ozone depleting substances; n-Propyl bromide in solvent cleaning; final rule. Federal 

Register 2007;72:30142--67. Available at http://www.epa.gov/fedrgstr/EPA-AIR/2007/May/Day30/a9707.pdf. 

† Environmental Protection Agency. 40 CFR part 82. Protection of stratospheric ozone: listing of substitutes 

for ozone depleting substances; n-Propyl bromide for use in adhesives, coatings, and aerosols; notice of 

proposed rulemaking. Federal Register 2007;72:30168--207. Available at 

http://www.epa.gov/fedrgstr/EPA-AIR/2007/May/Day-30/a9706.pdf. 

§ Available at http://www.cdc.gov/niosh/topics/dryclean.