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 This information may be superseded by new developments in the field of industrial hygiene.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 ETHYL BENZENE

INTRODUCTION

This guideline summarizes pertinent information about ethyl benzene 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 Recommendations may be superseded by new developments in these fields; readers are therefore advised to regard these recommendations as general guidelines and to determine whether new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(6)H(5)C(2)H(5)

* Structure

(For Structure, see paper copy)

* Synonyms

Phenylethane, ethylbenzol, EB

* Identifiers

1. CAS No.: 100-41-4

2. RTECS No.: DA0700000

3. DOT UN: 1175 26

4. DOT label: Flammable liquid

* Appearance and odor

Ethyl benzene is a colorless, flammable liquid with an aromatic odor. The air odor threshold concentration for ethyl benzene is 2.3 parts per million (ppm) parts of air.

CHEMICAL AND PHYSICAL PROPERTIES

* Physical data

1. Molecular weight: 106.16

2. Boiling point (at 760 mm Hg): 136.2 degrees C (277.3 degrees F)

3. Specific gravity: 0.867 at 20 degrees C (68 degrees F)

4. Vapor density: 3.7

5. Melting point: -95 degrees C (-139 degrees F)

6. Vapor pressure at 20 degrees C (68 degrees F): 7.1 mm Hg

7. Solubility: Practically insoluble in water; miscible with alcohol and ether; soluble in carbon tetrachloride and benzene.

8. Evaporation rate: Data not available.

* Reactivity

1. Conditions contributing to instability: Exposure to ignition sources such as, heat, sparks, or open flame may create a fire or explosion hazard.

2. Incompatibilities: Contact of ethyl benzene with strong oxidizing agents should be avoided.

3. Hazardous decomposition products: None reported.

Special precautions: None reported.

* Flammability

The National Fire Protection Association has assigned a flammability rating of 3 (serious fire hazard) to ethyl benzene.

1. Flash point: 18 degrees C (64 degrees F) (closed cup)

2. Autoignition temperature: 432 degrees C (810 degrees F).

3. Flammable limits in air (percent by volume): Lower, 1.0; upper, 6.7.

4. Extinguishant: For small fires use dry chemical, carbon dioxide, water spray, or alcohol-resistant foam. Use water spray, fog, or alcohol-resistant foam to fight large fires involving ethyl benzene.

Fires involving ethyl benzene should be fought upwind from the maximum distance possible. Keep unnecessary people away; isolate the hazard area and deny entry. Isolate the area for 1/2 mile in all directions if a tank, rail car, or tank truck is involved in the fire. For a massive fire in a cargo area, use unmanned hose holders or monitor nozzles; if this is impossible, withdraw from the area and let the fire burn. Emergency personnel should stay out of low areas. Vapors may travel to a source of ignition and flash back. Vapors are an explosion and poison hazard indoors, outdoors, or in sewers. Containers of ethyl benzene may explode in the heat of the fire and should be moved from the fire area if it is possible to do so safely. If this is not possible, cool fire exposed containers from the sides with water until well after the fire is out. Stay away from the ends of containers. Personnel should withdraw immediately if a rising sound from a venting safety device is heard or if there is discoloration of a container due to fire. Firefighters should wear a full set of protective clothing and self-contained breathing apparatus when fighting fires involving ethyl benzene.

EXPOSURE LIMITS

* OSHA PEL

The current Occupational Safety and Health Administration (OSHA) permissible exposure limit (PEL) for ethyl benzene is 100 ppm (435 milligrams per cubic meter (mg/m(3))) as an 8-hour time-weighted average (TWA) concentration() [29 CFR 1910.1000, Table Z-1].

* NIOSH REL

The National Institute for Occupational Safety and Health (NIOSH) has established recommended exposure limits (RELs) for ethyl benzene of 100 ppm (435 mg/m(3)) as a TWA for up to a 10-hour workday and a 40-hour workweek and 125 ppm (545 mg/m(3)) as a short-term exposure limit [NIOSH 1992].

* ACGIH TLV

The American Conference of Governmental Industrial Hygienists (ACGIH) has assigned ethyl benzene a threshold limit value (TLV) of 100 ppm (434 mg/m(3)) as a TWA for a normal 8-hour workday and a 40-hour workweek and a short-term exposure limit (STEL) of 125 ppm (543 mg/m(3)) for periods not to exceed 15 minutes. Exposures at the STEL concentration should not be repeated more than four times a day and should be separated by intervals of at least 60 minutes [ACGIH 1994, p. 21].

* Rationale for Limits

The NIOSH limits are based on the risk of eye, skin, and upper respiratory irritation [NIOSH 1992].

The ACGIH limits are based on the risk of irritation [ACGIH 1991, p. 583].

HEALTH HAZARD INFORMATION

* Routes of Exposure

Exposure to ethyl benzene can occur through inhalation, ingestion, eye or skin contact, and absorption through the skin [Sittig 1991, p. 741].

* Summary of toxicology

1. Effects on Animals: Ethyl benzene is an eye irritant; at high concentrations, it causes narcosis. Ethyl benzene also causes liver and kidney damage and has embryotoxic and teratogenic effects. The oral LD(50) in rats is 3,500 mg/kg, and the LC(50) in rats is 4,000 ppm for 4 hours [NIOSH 1991]. The dermal LD(50) in rabbits is 5,000 mg/kg [NIOSH 1991]. Chronic inhalation studies in guinea pigs, monkeys, rabbits, and rats exposed at concentrations of 400 to 2200 ppm for 7 to 8 hours/day, 5 days/week for up to 6 months revealed some liver toxicity [ACGIH 1991]. Inhalation of 600 ppm for 186 days caused changes in liver and kidney weights in rats and guinea pigs, and, in rabbits and monkeys, histopathology of the testes [Hathaway et al. 1991]. In rats, ethyl benzene has caused central nervous system disorders, toxic hepatitis, and upper respiratory tract irritation at high concentrations [Parmeggiani 1983]. Pregnant rats exposed to 100 or 1,000 ppm 6 hours/day on days 1 through 19 of gestation had offspring with significant increases in extra rib formation; at 100 ppm, maternal toxicity, evidenced by increased liver, kidney, and spleen weights, was observed [Hathaway et al. 1991]. Repeated dermal application of ethyl benzene in rabbits produced erythema, edema, and superficial necrosis [ACGIH 1991]. Two drops of the liquid instilled in rabbit eyes caused slight conjunctivitis [Hathaway et al. 1991].

2. Effects on Humans: Ethyl benzene is an irritant of the eyes, mucous membranes, and skin. By analogy with effects seen in animals, it may cause narcosis at high concentrations [Hathaway et al. 1991]. At a vapor concentration of 200 ppm, it causes transient irritation effects on the eyes; at 1,000 ppm, there is tearing and irritation; at 2,000 ppm, tearing and eye irritation are severe and nasal irritation is evident; at 5,000 ppm, there is intolerable irritation of the eyes and nose [ACGIH 1991]. Chronic exposure to a concentration above 100 ppm causes fatigue, headache, and mild eye and respiratory tract irritation [Hathaway et al. 1991]. Aspiration of ethyl benzene causes extensive pulmonary edema and hemorrhage [Genium 1992]. Ethyl benzene is rapidly absorbed through the skin; absorption through the skin of the hands and forearms occurs at the rate of 22 to 33 mg/cm(2)/hr [Hathaway et al. 1991]. Repeated exposure of the skin produces reddening, blistering, and, on chronic exposure, dermatitis. Ethyl benzene causes sister chromatid exchanges in human test systems [NIOSH 1991].

* Signs and symptoms of exposure

1. Acute exposure: Acute exposure to ethyl benzene causes eye, skin, and mucous membrane irritation, with tearing of the eyes, irritation of the nose and upper respiratory tract, and redness and blistering of the skin. Symptoms of narcosis include fatigue, drowsiness, staggering gait, and incoordination.

2. Chronic exposure: Chronic exposure to ethyl benzene causes fatigue, headache, and eye and upper respiratory tract irritation. Repeated contact with the skin may cause drying, defatting, and dermatitis [Genium 1992].

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 ethyl benzene and lead to worker exposures to this substance:

* The manufacture and transportation of ethyl benzene

* The manufacture of styrene monomer, cellulose acetate, and synthetic rubber

* The manufacture of paints, varnishes, and other surface coatings

* The manufacture and application of rubber adhesives

Methods that are effective in controlling worker exposures to ethyl benzene, 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 ethyl benzene 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 ethyl benzene, 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 eyes, skin, upper respiratory tract, and central nervous system. 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 ethyl benzene 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 eyes, skin, upper respiratory tract, and central nervous system.

* 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 ethyl benzene exposure. The interviews, examinations, and medical screening tests should focus on identifying the adverse effects of ethyl benzene on the eyes, skin, upper respiratory tract, or central nervous system. 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.

* Biological monitoring

Biological monitoring involves sampling and analyzing body tissues or fluids to provide an index of exposure to a toxic substance or metabolite. Exposure to ethyl benzene can be measured in the exhaled air (as ethyl benzene) or in urine as the metabolite mandelic acid. The biological exposure index for ethyl benzene in urine is 1.5 grams mandelic acid/gram creatinine.

WORKPLACE MONITORING AND MEASUREMENT

Determination of a worker's exposure to airborne ethyl benzene 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 (TWA or STEL) until a maximum collection volume of 24 liters (TWA) is reached (3 liters for STEL sampling. The sample is then treated with 99:1 carbon disulfide:dimethylformamide. Analysis is conducted by gas chromatography using a flame ionization detector (GC-FID). This method is described in the OSHA Computerized Information System [OSHA 1994] and is fully validated. NIOSH Method No. 1501 for aromatic hydrocarbons can also be used to determine a worker's airborne exposure to ethyl benzene. This method is the reference method for the OSHA method described above and differs only in its use of carbon disulfide as the solvent used to extract the sample [NIOSH 1994b].

PERSONAL HYGIENE PROCEDURES

If ethyl benzene contacts the skin, workers should immediately wash the affected areas with large amounts of soap and water.

Clothing contaminated with ethyl benzene 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 ethyl benzene, particularly its potential for causing irritation.

A worker who handles ethyl benzene 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 ethyl benzene or a solution containing ethyl benzene is handled, processed, or stored.

STORAGE

Ethyl benzene 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 ethyl benzene should be protected from physical damage and should be stored separately from strong oxidizing agents [NIOSH 1994a; Genium 1992].

SPILLS AND LEAKS

In the event of a spill or leak involving ethyl benzene, persons not wearing protective equipment and 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. Remove all sources of heat and ignition.

3. Ventilate potentially explosive atmospheres.

4. Do not touch the spilled material; stop the leak if it is possible to do so without risk.

5. Use non-sparking tools.

6. Use water spray to reduce vapors.

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

8. For large liquid spills, build dikes far ahead of the spill to contain the ethyl benzene for later reclamation or disposal [DOT 1993, Guide 26].

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

Ethyl benzene 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 ethyl benzene is 1,000 pounds. 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 ethyl benzene per calendar year or otherwise use 10,000 pounds or more of ethyl benzene 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 ethyl benzene 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. Although ethyl benzene is not specifically listed as a hazardous waste under RCRA, EPA requires employers to treat waste as hazardous if it exhibits any of the characteristics discussed above.

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 ethyl benzene 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 ethyl benzene. 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 ethyl benzene. The resistance of various materials to permeation by ethyl benzene is shown below:

(*) Not recommended, degradation may occur

To evaluate the use of these PPE materials with ethyl benzene, 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 ethyl benzene.

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.

REFERENCES

ACGIH [1991]. Documentation of the threshold limit values and biological exposure indices. 6th ed. Cincinnati, OH: American Conference of Governmental Industrial Hygienists.

ACGIH [1994]. 1994-1995 Threshold limit values for chemical substances and physical agents and biological exposure indices. Cincinnati, OH: American Conference of Governmental Industrial Hygienists.

AIHA [1978]. Hygienic guide series. Akron, OH: American Industrial Hygiene Association.

Amoore JE, Hautala E [1983]. Odor as an aid to chemical safety: odor thresholds compared with threshold limit values and volatilities for 214 industrial chemicals in air and water dilution. J of App Tox 3(6):272-290.

ATS [1987]. Standardization of spirometry -- 1987 update. American Thoracic Society. Am Rev Respir Dis 136:1285-1296.

CFR. Code of Federal regulations. Washington, DC: U.S. Government Printing Office, Office of the Federal Register.

DOT [1993]. 1993 Emergency response guidebook, guide 26. Washington, DC: U.S. Department of Transportation, Office of Hazardous Materials Transportation, Research and Special Programs Administration.

Forsberg K, Mansdorf SZ [1993]. Quick selection guide to chemical protective clothing. New York, NY: Van Nostrand Reinhold.

Genium [1992]. Material safety data sheet No. 385. Schenectady, NY: Genium Publishing Corporation.

Gosselin RE, Smith RP, Hodge HC [1984]. Clinical toxicology of commercial products. 5th ed. Baltimore, MD: Williams & Wilkins.

Hathaway GJ, Proctor NH, Hughes JP, and Fischman ML [1991]. Proctor and Hughes' chemical hazards of the workplace. 3rd ed. New York, NY: Van Nostrand Reinhold.

Lewis RJ, ed. [1993]. Lewis condensed chemical dictionary. 12th ed. New York, NY: Van Nostrand Reinhold Company.

Mickelsen RL, Hall RC [1987]. A breakthrough time comparison of nitrile and neoprene glove materials produced by different glove manufacturers. Am Ind Hyg Assoc J 48(11): 941-947.

Mickelsen RL, Hall RC, Chern RT, Myers JR [1991]. Evaluation of a simple weight-loss method for determining the permeation of organic liquids through rubber films. Am Ind Hyg Assoc J 52(10): 445-447.

NFPA [1986]. Fire protection guide on hazardous materials. 9th ed. Quincy, MA: National Fire Protection Association.

NIOSH [1987a]. NIOSH guide to industrial respiratory protection. Cincinnati, OH: U.S. Department of Health and Human Services, Public Health Service, Centers for Disease Control, National Institute for Occupational Safety and Health, DHHS (NIOSH) Publication No. 87-116.

NIOSH [1987b]. NIOSH respirator decision logic. Cincinnati, OH: U.S. Department of Health and Human Services, Public Health Service, Centers for Disease Control, National Institute for Occupational Safety and Health, DHHS (NIOSH) Publication No. 87-108.

NIOSH [1991]. Registry of toxic effects of chemical substances: Ethyl Benzene. Cincinnati, OH: U.S. Department of Health and Human Services, Public Health Service, Centers for Disease Control, National Institute for Occupational Safety and Health, Division of Standards Development and Technology Transfer, Technical Information Branch.

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, National Institute for Occupational Safety and Health, DHHS (NIOSH) Publication No. 92-100.

NIOSH [1994a]. NIOSH pocket guide to chemical hazards. Cincinnati, OH: U.S. Department of Health and Human Services, Public Health Service, Centers for Disease Control, National Institute for Occupational Safety and Health, DHHS (NIOSH) Publication No. 94-116.

NIOSH [1994b]. NIOSH manual of analytical methods. 4th ed. Cincinnati, OH: U.S. Department of Health and Human Services, Public Health Service, Centers for Disease Control, National Institute for Occupational Safety and Health, DHHS (NIOSH) Publication No. 94-113.

NJDH [1989]. Hazardous substance fact sheet: Ethyl Benzene. Trenton, NJ: New Jersey Department of Health.

NLM [1992]. Hazardous substances data bank: Ethyl Benzene. Bethesda, MD: National Library of Medicine.

OSHA [1994]. Computerized information system. Washington, DC: U.S. Department of Labor, Occupational Safety and Health Administration.

Patnaik P [1992]. A comprehensive guide to the hazardous properties of chemical substances. New York, NY: Van Nostrand Reinhold.

Sax NI, Lewis RJ [1989]. Dangerous properties of industrial materials. 7th ed. New York, NY: Van Nostrand Reinhold Company.

Sittig M [1991]. Handbook of toxic and hazardous chemicals. 3rd ed. Park Ridge, NJ: Noyes Publications.

USC. United States code. Washington. DC: U.S. Government Printing Office.

Windholz M, ed. [1983]. Windholz Index 10th ed. Rahway, NJ: Windholz & Company.