Disclaimer: These guidelines were developed under contract using generally accepted secondary sources. The protocol used by the contractor for surveying these data sources was developed by the National Institute for Occupational Safety and Health (NIOSH), the Occupational Safety and Health Administration (OSHA), and the Department of Energy (DOE). The information contained in these guidelines is intended for reference purposes only. None of the agencies have conducted a comprehensive check of the information and data contained in these sources. It provides a summary of information about chemicals that workers may be exposed to in their workplaces. The secondary sources used for supplements 111 and 1V were published before 1992 and 1993, respectively, and for the remainder of the guidelines the secondary sources used were published before September 1996. This information may be superseded by new developments in the field of industrial hygiene. Therefore readers are advised to determine whether new information is available.

OCCUPATIONAL SAFETY AND HEALTH GUIDELINE FOR ETHYLENE DIBROMIDE

INTRODUCTION

This guideline summarizes pertinent information about ethylene dibromide for workers and employers as well as for physicians, industrial hygienists, and other occupational safety and health professionals who may need such information to conduct effective occupational safety and health programs. Recommendations may be superseded by new developments in these fields; readers are therefore advised to regard these recommendations as general guidelines and to determine whether new information is available.

SUBSTANCE IDENTIFICATION

* Formula

C(2)H(4)Br(2)

* Structure

(For Structure, see paper copy)

* Synonyms

1,2-Dibromoethane, ethylene bromide, Bromofume, Dowfume EDB, Soilbrom 40, DBE, EDB, glycol bromide, blycol dibromide

* Identifiers

1. CAS No.: 106-93-4

2. RTECS No.: KH9275000

3. DOT UN: 1605 55

4. Specific DOT label: Poison

* Appearance and odor

Ethylene dibromide is a colorless, heavy, nonflammable liquid with a mild, chloroform-like odor. The minimum air odor threshold concentration is 10 parts per million (ppm) parts of air.

CHEMICAL AND PHYSICAL PROPERTIES

* Physical data

1. Molecular weight: 187.9

2. Boiling point (at 760 mm Hg): 131 degrees C (268 degrees F)

3. Specific gravity (water = 1): 2.17 at 25 degrees C (77 degrees F)

4. Vapor density: 6.5

5. Freezing point: 9 degrees C (48.2 degrees F)

6. Vapor pressure at 25 degrees C (77 degrees F): 11 mm Hg

7. Solubility: Slightly soluble in water; soluble in alcohol, ether, acetone, and benzene.

8. Evaporation rate: Data not available.

* Reactivity

1. Conditions contributing to instability: Heat and/or light cause ethylene dibromide to decompose slowly to produce hydrogen bromide, and moisture causes it to hydrolyze slowly.

2. Incompatibilities: Ethylene dibromide reacts with chemically active metals such as sodium, potassium, calcium, powdered aluminum, zinc, and magnesium, with liquid ammonia, and with strong oxidizers.

3. Hazardous decomposition products: Toxic gases and vapors (such as hydrogen bromide, bromine, and carbon monoxide) may be released in a fire involving ethylene dibromide.

4. Special precautions: None reported.

* Flammability

The National Fire Protection Association has assigned a flammability rating of 0 (no fire hazard) to ethylene dibromide.

1. Flash point: Nonflammable

2. Autoignition temperature: Nonflammable

3. Flammable limits in air: Nonflammable

4. Extinguishant: Use an extinguishant that is suitable for the materials involved in the surrounding fire.

Fires involving ethylene dibromide should be fought upwind from the maximum distance possible. Isolate the hazard area and deny access to unnecessary personnel. Firefighters should wear a full set of protective clothing and self-contained breathing apparatus when fighting fires involving ethylene dibromide.

EXPOSURE LIMITS

* OSHA PEL

The current Occupational Safety and Health Administration (OSHA) permissible exposure limits (PELs) for ethylene dibromide are 20 parts per million (ppm) parts of air ()as an 8-hour time-weighted average (TWA) concentration, 30 ppm() as an acceptable ceiling concentration with a maximum duration of 5 minutes, and 50 ppm as an acceptable maximum peak [29 CFR 1910.1000, Table Z-2].

* NIOSH REL

The National Institute for Occupational Safety and Health (NIOSH) has established a recommended exposure limit (REL) for ethylene dibromide of 0.045 ppm ()as a TWA for up to a 10-hour workday and a 40-hour workweek and 0.13 ppm as a 15-minute ceiling. NIOSH considers ethylene dibromide a potential occupational carcinogen [NIOSH 1992].

* ACGIH TLV

The American Conference of Governmental Industrial Hygienists (ACGIH) has designated ethylene dibromide as an A2 substance (suspected human carcinogen) and has not assigned a numerical limit. The ACGIH assigns a "Skin" notation, which indicates that the cutaneous route of exposure (including mucous membranes and eyes) contributes to overall exposure [ACGIH 1994, p. 21].

* Rationale for Limits

The NIOSH limit is based on the risk of potential for cancer;

mutagenesis; damage to the skin, eyes, heart, liver, spleen, central nervous system, and reproductive and respiratory systems [NIOSH 1992].

The ACGIH designation is based on the potential for cancer [ACGIH 1991, p. 607].

HEALTH HAZARD INFORMATION

* Routes of Exposure

Exposure to ethylene dibromide can occur through inhalation, ingestion, and eye or skin contact, and absorption through the skin [Sittig 1991, p. 758].

* Summary of toxicology

1. Effects on Animals: Ethylene dibromide is a severe mucous membrane, eye, and skin irritant. It is a liver, kidney, and lung toxin, and a reproductive toxin in experimental animals. Ethylene dibromide has been determined to be carcinogenic by the inhalation, ingestion, and dermal routes of exposure. In rats, the lowest lethal concentration by inhalation is 400 ppm for 2 hours; the oral LD(50) is 108 mg/kg. The dermal LD(50) in rabbits is 300 mg/kg [NIOSH 1995]. In experimental animals, a single exposure to ethylene dibromide vapor led to cell damage and swelling of the lungs, liver, and kidneys. Depression of the central nervous system was also noted. Rats were unable to survive exposure to 3,000 ppm for longer than 6 minutes. Death from high concentrations occurs within 24 hours as a result of central nervous system depression and cardiopulmonary failure. Low-level exposures may cause fatal pneumonia and death within 12 days. Chronic exposure to ethylene dibromide affects the lungs, liver, spleen, and circulatory system. In cats exposed 30 minutes per day for 10 days to 100 ppm ethylene dibromide, some deaths were caused by damage to the circulatory system and spleen enlargement [ACGIH 1991]. In another chronic exposure study involving several species, some rats and mice exposed to 100 ppm died within 2 weeks from damage to the lungs, liver, and spleen; at 50 ppm, half of the exposed rats died of pneumonia. Exposure to 25 ppm was tolerated by rats, guinea pigs, and rabbits for 6 months without noticeable effect [Clayton and Clayton 1982]. Dermal exposure to undiluted ethylene dibromide or to a 10 percent solution caused death in rabbits within 24 hours [Hathaway et al. 1991]. Repeated skin exposure to 1 percent ethylene dibromide in butylcarbitol acetate caused redness, swelling, cell death, and sloughing of the superficial layers of skin of rabbits. Eye exposure to undiluted ethylene dibromide caused pain and irritation, which cleared within 2 days, and superficial corneal necrosis, which healed completely [Clayton and Clayton 1982]. The mutagenic potential of ethylene dibromide is well established in both plant and animal systems [ACGIH 1991]. Animal studies have shown reproductive effects in exposed males; these effects consist of testicular atrophy in rats, and sperm abnormalities and decreased sperm count in bulls. The concurrent exposure to disulfiram (Antabuse) potentiated the reproductive toxicity of ethylene dibromide [Hathaway et al. 1991]. In another animal study, minor skeletal abnormalities were observed in the offspring of mice and rats following gestational exposure of 32 ppm [ACGIH 1991]. Four long-term bioassays for the carcinogenicity of ethylene dibromide have been conducted: two by inhalation, one by oral gavage, and the other by skin painting. After an extensive review of these studies, the International Agency for Research on Cancer (IARC) found sufficient evidence of the carcinogenicity of ethylene bromide to animals. This classification was based on 1) the adenomas and carcinomas of the nasal cavity, hemangiosarcomas of the spleen, mammary tumors, subcutaneous mesenchymal tumors, an increased incidence of alveolar/bronchiolar lung tumors in animals of each species, and an increased incidence of peritoneal mesotheliomas in male rats following inhalation of ethylene dibromide; 2) squamous-cell carcinomas of the forestomach in animals of each species, an increased incidence of alveolar/bronchiolar lung tumors in mice of each sex, liver carcinomas in female rats, hemangiosarcomas in male rats and esophageal papillomas in female mice following oral administration; skin and lung tumors in mice following skin application of ethylene dibromide [IARC 1987; ACGIH 1991].

2. Effects on Humans: Ethylene dibromide is a severe eye, mucous membrane, and skin irritant, and a liver, kidneys, and lungs toxin. The epidemiological evidence for ethylene dibromide's carcinogenicity in humans is inconclusive because of limitations in study design, inadequate latency periods, and incomplete exposure data [Hathaway et al. 1991; ACGIH 1991]. There is no evidence that ethylene dibromide causes fertility or fetal problems in workers [NLM 1995]. Human fatalities from ethylene dibromide exposure have been caused by acute liver and kidney damage. One reported case involved two workers who collapsed while inside a tank that was later found to contain a 0.1% to 0.3% ethylene dibromide solution. Both individuals experienced vomiting, diarrhea, abdominal pain, and burning of the eyes and throat. Acute kidney and liver failure preceded death [ACGIH 1991]. In another case, a woman ingested 4.5 ml of ethylene dibromide and died after experiencing vomiting, nausea, diarrhea, and kidney failure; at autopsy, massive liver and kidney damage was seen [Hathaway et al. 1991]. Contact of the skin with ethylene dibromide causes pain, hyperemia, and blistering, and may cause sensitization [Hathaway et al. 1991].

* Signs and symptoms of exposure

1. Acute exposure: Exposures to concentrations of 100 to 200 of ethylene dibromide cause abdominal pain, vomiting, diarrhea, and eye and respiratory irritation [ACGIH 1991]. Other signs and symptoms of acute inhalation exposure are lung congestion and edema, followed by delayed-onset pneumonia [Parmeggiani 1983] and drowsiness, headache, loss of appetite, and central nervous system depression [Genium 1989]. The liquid chemical on the skin causes redness, swelling, burning pain, blisters, and ulceration [Parmeggiani 1983; Clayton and Clayton 1982]. Ingestion causes excitement, headache, ringing in the ears, generalized weakness, a weak pulse, severe protracted vomiting, and liver and kidney failure; death may follow severe overexposures [Parmeggiani 1983; Hathaway et al. 1991].

2. Chronic exposure: Chronic exposure to ethylene dibromide causes irritation of the conjunctiva, upper respiratory tract irritation, severe loss of appetite, headache, and depression [ACGIH 1986].

EMERGENCY MEDICAL PROCEDURES

* Emergency medical procedures: [NIOSH to supply]

5. Rescue: Remove an incapacitated worker from further exposure and implement appropriate emergency procedures (e.g., those listed on the Material Safety Data Sheet required by OSHA's Hazard Communication Standard [29 CFR 1910.1200]). All workers should be familiar with emergency procedures, the location and proper use of emergency equipment, and methods of protecting themselves during rescue operations.

EXPOSURE SOURCES AND CONTROL METHODS

The following operations may involve ethylene dibromide and lead to worker exposures to this substance:

* The manufacture and transportation of ethylene dibromide * Use as a fumigant in preplanting operations, and on grains, fruits, tobacco, seeds, seed beds, and vegetables; in mills and warehouses * Use in antiknock fluids and fuels; as a scavenger for lead in gasoline

* Use in production of waterproofing agents, fire extinguishing agents, and gauge fluids during manufacture of measuring instruments * Use in organic synthesis in production of dyes, pharmaceuticals, perfumes, vinyl bromide, and ethylene oxide; used as a specialty solvent for resins, gums, waxes, celluloid, fats, and oils

Methods that are effective in controlling worker exposures to ethylene dibromide, depending on the feasibility of implementation, are as follows:

* Process enclosure * Local exhaust ventilation * General dilution ventilation * Personal protective equipment

Workers responding to a release or potential release of a hazardous substance must be protected as required by paragraph (q) of OSHA's Hazardous Waste Operations and Emergency Response Standard [29 CFR 1910.120].

Good sources of information about control methods are as follows:

1. ACGIH [1992]. Industrial ventilation--a manual of recommended practice. 21st ed. Cincinnati, OH: American Conference of Governmental Industrial Hygienists.

2. Burton DJ [1986]. Industrial ventilation--a self study companion. Cincinnati, OH: American Conference of Governmental Industrial Hygienists.

3. Alden JL, Kane JM [1982]. Design of industrial ventilation systems. New York, NY: Industrial Press, Inc.

4. Wadden RA, Scheff PA [1987]. Engineering design for control of workplace hazards. New York, NY: McGraw-Hill.

5. Plog BA [1988]. Fundamentals of industrial hygiene. Chicago, IL: National Safety Council.

MEDICAL SURVEILLANCE

OSHA is currently developing requirements for medical surveillance. When these requirements are promulgated, readers should refer to them for additional information and to determine whether employers whose employees are exposed to ethylene dibromide are required to implement medical surveillance procedures.

* Medical Screening

Workers who may be exposed to chemical hazards should be monitored in a systematic program of medical surveillance that is intended to prevent occupational injury and disease. The program should include education of employers and workers about work-related hazards, early detection of adverse health effects, and referral of workers for diagnosis and treatment. The occurrence of disease or other work-related adverse health effects should prompt immediate evaluation of primary preventive measures (e.g., industrial hygiene monitoring, engineering controls, and personal protective equipment). A medical surveillance program is intended to supplement, not replace, such measures. To detect and control work-related health effects, medical evaluations should be performed (1) before job placement, (2) periodically during the term of employment, and (3) at the time of job transfer or termination.

* Preplacement medical evaluation

Before a worker is placed in a job with a potential for exposure to ethylene dibromide, a licensed health care professional should evaluate and document the worker's baseline health status with thorough medical, environmental, and occupational histories, a physical examination, and physiologic and laboratory tests appropriate for the anticipated occupational risks. These should concentrate on the function and integrity of the skin, eyes, respiratory tract, liver, and kidneys. Medical surveillance for respiratory disease should be conducted using the principles and methods recommended by the American Thoracic Society.

A preplacement medical evaluation is recommended to assess medical conditions that may be aggravated or may result in increased risk when a worker is exposed to ethylene dibromide at or below the prescribed exposure limit. The health care professional should consider the probable frequency, intensity, and duration of exposure as well as the nature and degree of any applicable medical condition. Such conditions (which should not be regarded as absolute contraindications to job placement) include a history and other findings consistent with diseases of the skin, eyes, respiratory tract, liver, and kidneys.

* Periodic medical evaluations

Occupational health interviews and physical examinations should be performed at regular intervals during the employment period, as mandated by any applicable Federal, State, or local standard. Where no standard exists and the hazard is minimal, evaluations should be conducted every 3 to 5 years or as frequently as recommended by an experienced occupational health physician. Additional examinations may be necessary if a worker develops symptoms attributable to ethylene dibromide exposure. The interviews, examinations, and medical screening tests should focus on identifying the adverse effects of ethylene dibromide on the skin, eyes, respiratory tract, liver, or kidneys. Current health status should be compared with the baseline health status of the individual worker or with expected values for a suitable reference population.

* Termination medical evaluations

The medical, environmental, and occupational history interviews, the physical examination, and selected physiologic or laboratory tests that were conducted at the time of placement should be repeated at the time of job transfer or termination to determine the worker's medical status at the end of his or her employment. Any changes in the worker's health status should be compared with those expected for a suitable reference population. Because occupational exposure to ethylene dibromide may cause diseases with prolonged latent periods, the need for medical surveillance may extend well beyond the termination of employment.

* Biological monitoring

Biological monitoring involves sampling and analyzing body tissues or fluids to provide an index of exposure to a toxic substance or metabolite. No biological monitoring test acceptable for routine use has yet been developed for ethylene dibromide.

WORKPLACE MONITORING AND MEASUREMENT

Determination of a worker's exposure to airborne ethylene dibromide is made using a charcoal tube (100/50 mg sections, 20/40 mesh). Samples are collected at a maximum flow rate of 0.2 liter/minute (for TWA, ceiling, or peak samples) until a maximum collection volume of 10 liters is reached (TWA) or for a minimum time of 5 minutes for ceiling or peak samples. The sample is then treated with xylene. Analysis is conducted by gas chromatography using an electron capture detector (GC/ECD). This method is fully validated and is described in the OSHA Computerized Information System [OSHA 1994] and in NIOSH Method No. 1008 [NIOSH 1994b].

PERSONAL HYGIENE PROCEDURES

If ethylene dibromide contacts the skin, workers should immediately wash the affected areas with soap and water.

Clothing contaminated with ethylene dibromide should be removed immediately, and provisions should be made for the safe removal of the chemical from the clothing. Persons laundering the clothes should be informed of the hazardous properties of ethylene dibromide, particularly its potential for causing systemic toxicity through dermal absorption.

A worker who handles ethylene dibromide should thoroughly wash hands, forearms, and face with soap and water before eating, using tobacco products, using toilet facilities, applying cosmetics, or taking medication.

Workers should not eat, drink, use tobacco products, apply cosmetics, or take medication in areas where ethylene dibromide or a solution containing ethylene dibromide is handled, processed, or stored.

STORAGE

Ethylene dibromide should be stored in a cool, dry, well-ventilated area in tightly sealed containers that are labeled in accordance with OSHA's Hazard Communication Standard [29 CFR 1910.1200]. Containers of ethylene dibromide should be protected from physical damage and should be stored separately from chemically active metals such as sodium, potassium, calcium, powdered aluminum, zinc, and magnesium, liquid ammonia, and strong oxidizers.

SPILLS AND LEAKS

In the event of a spill or leak involving ethylene dibromide, persons not wearing protective equipment and fully-encapsulating, vapor-protective clothing should be restricted from contaminated areas until cleanup has been completed. The following steps should be undertaken following a spill or leak:

1. Notify safety personnel.

2. Ventilate to reduce concentration of ethylene dibromide.

3. Do not touch the spilled material.

4. Stop leak if this can be done without risk.

5. Water spray may be used to reduce vapors.

6. For small liquid spills, take up with sand or other noncombustible absorbent material and place into closed containers for later disposal.

7. For large liquid spills, build dikes far ahead of the spill to contain the ethylene dibromide for later reclamation or disposal.

SPECIAL REQUIREMENTS

U.S. Environmental Protection Agency (EPA) requirements for emergency planning, reportable quantities of hazardous releases, community right-to-know, and hazardous waste management may change over time. Users are therefore advised to determine periodically whether new information is available.

* Emergency planning requirements

Ethylene dibromide is not subject to EPA emergency planning requirements under the Superfund Amendments and Reauthorization Act (SARA) (Title III) in 42 USC 11022.

* Reportable quantity requirements for hazardous releases

A hazardous substance release is defined by EPA as any spilling, leaking, pumping, pouring, emitting, emptying, discharging, injecting, escaping, leaching, dumping, or disposing into the environment (including the abandonment or discarding of contaminated containers) of hazardous substances. In the event of a release that is above the reportable quantity for that chemical, employers are required to notify the proper Federal, State, and local authorities [40 CFR 355.40].

The reportable quantity of ethylene dibromide is 1 pound. If an amount equal to or greater than this quantity is released within a 24-hour period in a manner that will expose persons outside the facility, employers are required to do the following:

- Notify the National Response Center immediately at (800) 424-8802 or at (202) 426-2675 in Washington, D.C. [40 CFR 302.6].

* Community right-to-know requirements

Employers who own or operate facilities in SIC codes 20 to 39 that employ 10 or more workers and that manufacture 25,000 pounds or more of ethylene dibromide per calendar year or otherwise use 10,000 pounds or more of ethylene dibromide per calendar year are required by EPA [40 CFR Part 372.30] to submit a Toxic Chemical Release Inventory form (Form R) to EPA reporting the amount of ethylene dibromide emitted or released from their facility annually.

* Hazardous waste management requirements

EPA considers a waste to be hazardous if it exhibits any of the following characteristics: ignitability, corrosivity, reactivity, or toxicity as defined in 40 CFR 261.21-261.24. Under the Resource Conservation and Recovery Act (RCRA) [40 USC 6901 et seq.], EPA has specifically listed many chemical wastes as hazardous. Ethylene dibromide is listed as a hazardous waste under RCRA and has been assigned EPA Hazardous Waste No. U067. It is approved for land disposal after treatment and only if the concentration of ethylene dibromide in the waste or treatment residual does not exceed 15 mg/kg.

Providing detailed information about the removal and disposal of specific chemicals is beyond the scope of this guideline. The U.S. Department of Transportation, EPA, and State and local regulations should be followed to ensure that removal, transport, and disposal of this substance are conducted in accordance with existing regulations. To be certain that chemical waste disposal meets EPA regulatory requirements, employers should address any questions to the RCRA hotline at (703) 412-9810 (in the Washington, D.C. area) or toll-free at (800) 424-9346 (outside Washington, D.C.). In addition, relevant State and local authorities should be contacted for information on any requirements they may have for the waste removal and disposal of this substance.

RESPIRATORY PROTECTION

* Conditions for respirator use

Good industrial hygiene practice requires that engineering controls be used where feasible to reduce workplace concentrations of hazardous materials to the prescribed exposure limit. However, some situations may require the use of respirators to control exposure. Respirators must be worn if the ambient concentration of ethylene dibromide exceeds prescribed exposure limits. Respirators may be used (1) before engineering controls have been installed, (2) during work operations such as maintenance or repair activities that involve unknown exposures, (3) during operations that require entry into tanks or closed vessels, and (4) during emergencies. Workers should only use respirators that have been approved by NIOSH and the Mine Safety and Health Administration (MSHA).

* Respiratory protection program

Employers should institute a complete respiratory protection program that, at a minimum, complies with the requirements of OSHA's Respiratory Protection Standard [29 CFR 1910.134]. Such a program must include respirator selection, an evaluation of the worker's ability to perform the work while wearing a respirator, the regular training of personnel, respirator fit testing, periodic workplace monitoring, and regular respirator maintenance, inspection, and cleaning. The implementation of an adequate respiratory protection program (including selection of the correct respirator) requires that a knowledgeable person be in charge of the program and that the program be evaluated regularly. For additional information on the selection and use of respirators and on the medical screening of respirator users, consult the latest edition of the NIOSH Respirator Decision Logic [NIOSH 1987b] and the NIOSH Guide to Industrial Respiratory Protection [NIOSH 1987a].

PERSONAL PROTECTIVE EQUIPMENT

Workers should use appropriate personal protective clothing and equipment that must be carefully selected, used, and maintained to be effective in preventing skin contact with ethylene dibromide. The selection of the appropriate personal protective equipment (PPE) (e.g., gloves, sleeves, encapsulating suits) should be based on the extent of the worker's potential exposure to ethylene dibromide. The resistance of various materials to permeation by ethylene dibromide is shown below:

(*) Not recommended, degradation may occur

To evaluate the use of these PPE materials with ethylene dibromide, users should consult the best available performance data and manufacturers' recommendations. Significant differences have been demonstrated in the chemical resistance of generically similar PPE materials (e.g., butyl) produced by different manufacturers. In addition, the chemical resistance of a mixture may be significantly different from that of any of its neat components.

Any chemical-resistant clothing that is used should be periodically evaluated to determine its effectiveness in preventing dermal contact. Safety showers and eye wash stations should be located close to operations that involve ethylene dibromide.

Splash-proof chemical safety goggles or face shields (20 to 30 cm long, minimum) should be worn during any operation in which a solvent, caustic, or other toxic substance may be splashed into the eyes.

In addition to the possible need for wearing protective outer apparel (e.g., aprons, encapsulating suits), workers should wear work uniforms, coveralls, or similar full-body coverings that are laundered each day. Employers should provide lockers or other closed areas to store work and street clothing separately. Employers should collect work clothing at the end of each work shift and provide for its laundering. Laundry personnel should be informed about the potential hazards of handling contaminated clothing and instructed about measures to minimize their health risk.

Protective clothing should be kept free of oil and grease and should be inspected and maintained regularly to preserve its effectiveness.

Protective clothing may interfere with the body's heat dissipation, especially during hot weather or during work in hot or poorly ventilated work environments.

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