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 This information may be superseded by new developments in the field of industrial hygiene.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

INTRODUCTION

This guideline summarizes pertinent information about dinitrotoluene 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 Recommendations may be superseded by new developments in these fields; readers are therefore advised to regard these recommendations as general guidelines and to determine whether new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(7)H(6)N(2)O(4)

* Structure

(For Structure, see paper copy)

* Synonyms

DNT, binitrotolunene, dinitrophenylmethane, methyldinitrobenzene, dinitrotoluol

* Identifiers

1. CAS No.: 25321-14-6

2. RTECS No.: XT1300000

3. DOT UN: 1600 (liquid and molten); UN 2038 (solid)

4. Specific DOT label: Poison

* Appearance and odor

Dinitrotoluene (commercial-grade) is a mixture of the 2,4-; 3,4; and

3,5-dinitrotoluene isomers and is a combustible, oily liquid. There are six isomers of dinitrotoluene, of which the 2,4-dinitrotoluene isomer is most important. In pure form, the isomers are yellow crystals. Technical-grade dinitrotoluene is composed primarily of the 2,4- and 2,6-dinitrotoluene isomers.

CHEMICAL AND PHYSICAL PROPERTIES

* Physical data (commercial mixture)

1. Molecular weight: 182.1

2. Boiling point (at 760 mm Hg): Decomposes at 300 degrees C (572 degrees F)

Specific gravity (water = 1): 1.32 at 20 degrees C (68 degrees F)

3. Vapor density: Not applicable.

4. Melting point: 71 degrees C (159.4 degrees F)

5. Vapor pressure at 20 degrees C (68 degrees F): 1 mm Hg

6. Solubility: Very slightly soluble in water; soluble in alcohol, ether, carbon disulfide, benzene, and acetone.

7. Evaporation rate: Not applicable.

* Reactivity

1. Conditions contributing to instability: Strong shock, friction, contamination, heat, or flames.

2. Incompatibilities: Contact between dinitrotoluene and strong oxidizers or reducing agents should be avoided. Contact with caustics and chemically active metals such as tin or zinc may cause formation of heat and an increase in pressure.

3. Hazardous decomposition products: Toxic gases and vapors (such as nitrogen oxides and carbon oxides) may be released in a fire involving dinitrotoluene.

4. Special precautions: Liquid dinitrotoluene attacks some forms of plastic, rubber and coatings.

* Flammability

The National Fire Protection Association has assigned a flammability rating of 1 (slight fire hazard) to dinitrotoluene.

1. Flash point: 270 degrees C (404 degrees F) (open cup/closed cup).

2. Autoignition temperature: Not applicable

3. Flammable limits in air: Not applicable

4. Extinguishant: Dry chemical, carbon dioxide, water spray, or standard foam for small fires. Use water spray, fog, or standard foam for large fires.

Fires involving dinitrotoluene should be fought upwind from the maximum distance possible. Keep unnecessary people away; isolate the hazard area and deny entry. 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 and ventilate closed spaces before entering. Containers of dinitrotoluene 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. Firefighters should wear a full set of protective clothing and self-contained breathing apparatus when fighting fires involving dinitrotoluene.

EXPOSURE LIMITS

* OSHA PEL

The current Occupational Safety and Health Administration (OSHA) permissible exposure limit (PEL) for dinitrotoluene is 1.5 milligrams per cubic meter (mg/m(3)) of air as an 8-hour time-weighted average (TWA) concentration. The OSHA PEL also bears a "Skin" notation, which indicates that the cutaneous route of exposure (including mucous membranes and eyes) contributes to overall exposure [29 CFR 1910.1000, Table Z-1.

* NIOSH REL

The National Institute for Occupational Safety and Health (NIOSH) has established a recommended exposure limit (REL) for dinitrotoluene of 1.5 mg/m(3) as a TWA for up to a 10-hour workday and a 40-hour workweek. NIOSH also assigns a "Skin" notation to dinitrotoluene. NIOSH considers dinitrotoluene a potential occupational carcinogen [NIOSH 1992].

* ACGIH TLV

The American Conference of Governmental Industrial Hygienists (ACGIH) has assigned dinitrotoluene a threshold limit value (TLV) of 1.5 mg/m(3) as a TWA for a normal 8-hour workday and a 40-hour workweek and considers it a suspected human carcinogen. The ACGIH also assigns a "Skin" notation to dinitrotoluene [ACGIH 1994, p. 20].

* Rationale for Limits

The NIOSH limit is based on the risk of cancer and reproductive effects; tumors of the liver, skin, and kidneys in animals [NIOSH 1992].

The ACGIH limit is based on analogy to the effects of nitrobenzene [ACGIH 1991, p. 510].

HEALTH HAZARD INFORMATION

* Routes of Exposure

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

* Summary of toxicology

1. Effects on Animals: Dinitrotoluene (DNT) is a potent liver toxin and carcinogen in rats. Prolonged exposure to DNT causes methemoglobinemia. DNT is a neurotoxin in dogs and has reproductive effects in all species tested. Animal studies involving technical-grade dinitrotoluene, the mixture of isomers available commercially, or 2,6-DNT, the isomer in the mixture that is known to be responsible for the technical grade's carcinogenic effects, are of greatest interest from the standpoint of occupational health. Administered orally, DNT has caused hematological effects, including methemoglobinemia, anemia, reticulocytosis, and increases in the number of Heinz bodies, in all species tested [NLM 1992]. The oral lethal dose of the various DNT isomers range from 216 mg/kg for 3,5-DNT in female rats to 1,954 mg/kg for 2,4-DNT in male mice [ACGIH 1991]. 3,5-DNT has the greatest toxic effect in both male and female rats and mice when compared to other isomers [ACGIH 1991]. Hepatotoxic effects have consistently been seen in dogs, mice, and rats administered DNT orally [NLM 1992]. Rats fed 15 ppm (4.5 mg/kg/day) for 24 months developed hepatic dysplasia and hepatocellular carcinomas. Technical-grade DNT fed to rats for 24 months caused liver discoloration at a dose of 3.5 mg/kg/day and liver nodules and malignancies at a dose of 14 mg/kg/day [ACGIH 1991]. An NCI bioassay also showed that technical-grade DNT causes subcutaneous tissue fibromas in male rats and mammary gland fibroadenomas in female rate. DNT administered orally to dogs caused neurotoxic effects, with tremors, loss of coordination, and convulsions; neurotoxic effects are not seen in either rats or mice until much higher doses are given [Hathaway et al. 1991; NLM 1992]. Oral administration of DNT to rats, mice, and dogs causes reproductive effects, including testicular and ovarian atrophy, decreased fertility, and decreased sperm count [ACGIH 1991].

2. Effects on Humans: dinitrotoluene causes methemoglobinemia, the loss of the blood's oxygen-carrying capacity, in exposed workers [ACGIH 1991]. The first symptom of methemoglobinemia is headache, followed by fatigue, nausea, vomiting, and chest pain; onset may be delayed as long as 4 hours after exposure [ACGIH 1991]. Chronic exposure to dinitrotoluene causes anemia and jaundice [Clayton and Clayton 1982]. The signs and symptoms of dinitrotoluene poisoning are intensified by alcohol ingestion [NJDH 1992]. DNT can be absorbed through the skin in toxic amounts [ACGIH 1991; NLM 1992]. A study of DNT's reproductive effects in workers showed decreased sperm counts, slight abnormalities in the sperm of workers, and a slight increase in the rate of spontaneous abortions in their wives [NLM 1992]. A retrospective cohort mortality study of DNT-manufacturing and -producing workers found a significant increase in mortality due to ischemic heart disease; the average DNT exposure of these workers was estimated to be 1 mg/kg/day or less from inhalation, ingestion, and dermal sources [NLM 1992].

* Signs and symptoms of exposure

1. Acute exposure: Acute exposure to dinitrotoluene causes headache, fatigue, cyanosis, and shortness of breath on mild exertion; if exposure is severe, loss of coordination, nausea, drowsiness, vomiting, and rapid heartbeat may occur.

2. Chronic exposure: Chronic exposure causes anemia and jaundice, with weakness, fatigue, an increase in the liver enzymes, and decreased white blood cell count. Chronic exposure may also affect fertility and cause other reproductive effects. Studies in workers suggest that DNT may cause ischemic heart disease.

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 dinitrotoluene and lead to worker exposures to this substance:

* The manufacture and transportation of dinitrotoluene

* Used in the manufacture of toluene diisocyanate, which is used to produce polyurethane plastics

* Used in various ways in the production of explosives, e.g., to plasticize cellulose nitrate, to moderate the burning rate, to manufacture gelatin explosives (which are less sensitive to shock or friction) and to manufacture TNT; and as a waterproofing coating for some smokeless powders

* Used in the manufacture of toluidines, toluene diamine, and dyes

Methods that are effective in controlling worker exposures to dinitrotoluene, 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 dinitrotoluene 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 dinitrotoluene, 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 blood, liver, and heart.

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 dinitrotoluene 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 blood, liver, and heart.

* 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 dinitrotoluene exposure. The interviews, examinations, and medical screening tests should focus on identifying the adverse effects of dinitrotoluene on the blood, liver, and heart. 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 dinitrotoluene 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 dinitrotoluene.

WORKPLACE MONITORING AND MEASUREMENT

Determination of a worker's exposure to airborne dinitrotoluene is made using a glass fiber filter contained within a Tenax-GC tube. Samples are collected at a maximum flow rate of 1 liter/minute until a maximum collection volume of 60 liters is reached. The sample is then treated with acetone. Analysis is conducted by gas chromatography (GC/TEA/EAP). This method (OSHA 44) is fully validated and is described in the OSHA Computerized Information System [OSHA 1994].

PERSONAL HYGIENE PROCEDURES

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

Clothing contaminated with dinitrotoluene 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 dinitrotoluene, particularly its potential for causing toxic effects through skin absorption.

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

STORAGE

Dinitrotoluene 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 dinitrotoluene should be protected from physical damage, shock, and heat, and should be stored separately from strong oxidizers, reducing agents, caustics and chemically active metals such as tin or zinc.

SPILLS AND LEAKS

In the event of a spill or leak involving dinitrotoluene, 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. 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; do not get water inside the container.

7. For small dry spills, use a clean shovel and place the material into a clean, dry container; cover and remove the container from the spill area.

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

9. For large liquid spills, build dikes far ahead of the spill to contain the dinitrotoluene 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

Dinitrotoluene 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 dinitrotoluene is 10 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 dinitrotoluene per calendar year or otherwise use 10,000 pounds or more of dinitrotoluene 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 dinitrotoluene 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 dinitrotoluene 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 dinitrotoluene 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 dinitrotoluene. 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 dinitrotoluene. The resistance of various materials to permeation by dinitrotoluene is shown below:

(*) Not recommended, degradation may occur

To evaluate the use of these PPE materials with dinitrotoluene, 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 dinitrotoluene.

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

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NIOSH [1991]. Registry of toxic effects of chemical substances: Dinitrotoluene. 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.

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