Disclaimer: The information contained in these guidelines is intended for reference purposes only. It provides a summary of information about chemicals that workers may be exposed to in their workplaces. The information contained in these guidelines is current as of date of publication (September, 1996); recommendations may be superseded by new developments in the field of industrial hygiene. Readers are therefore advised to regard these recomendations as general guidelines and to determine whether new information is available.

OCCUPATIONAL SAFETY AND HEALTH GUIDELINE FOR TETRYL

INTRODUCTION

This guideline summarizes pertinent information about tetryl 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 Recommendations may be superseded by new developments; readers are therefore advised to regard these recommendations as general guidelines and to determine periodically whether new information is available.

SUBSTANCE IDENTIFICATION

* Formula

C(7)H(5)N(5)O(8)

* Structure

(For Structure, see paper copy)

* Synonyms

2,4,6-Trinitrophenylmethylnitramine; picrylmethylnitramine; nitramine; pyrenite.

* Identifiers

1. CAS: 479-45-8.

2. RTECS: BY6300000.

3. DOT UN: 0208 46.

4. DOT label: Explosive A.

* Appearance and odor

Tetryl is a colorless, odorless, highly explosive solid that turns yellow when exposed to light. It is not produced commercially in the United States.

CHEMICAL AND PHYSICAL PROPERTIES

* Physical data

1. Molecular weight: 287.15.

2. Boiling point (760 torr): Explodes at 187 degrees C (369 degrees F).

3. Specific gravity (water = 1): 1.57 at 19 degrees C (66 degrees F).

4. Vapor density: Not applicable.

5. Melting point: 129 degrees C (264 degrees F).

6. Vapor pressure at 20 degrees C (68 degrees F): Less than 1 torr.

7. Solubility: Insoluble in water; soluble in alcohol, ether, benzene, and glacial acetic acid.

8. Evaporation rate: Not applicable.

* Reactivity

1. Conditions contributing to instability: Heat, friction, and shock.

2. Incompatibilities: Contact of tetryl with some oxidizable materials, such as hydrazine and trioxygen difluoride, causes fires and explosions.

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

4. Special precautions: Tetryl must be protected from heat, friction, and shock.

* Flammability

The National Fire Protection Association has not assigned a flammability rating to tetryl. Other sources rate tetryl as a dangerous fire hazard when this substance is shocked or exposed to heat or open flame.

1. Flash point: Explodes in air.

2. Explosion temperature: 257 degrees C (459 degrees F).

3. Flammable limits in air: Not applicable.

4. Extinguishant: Use water to fight small fires involving tetryl; allow large fires to burn. Firefighters should wear a full set of protective clothing, including a self-contained breathing apparatus, when fighting fires involving tetryl.

* Warning properties

Tetryl is odorless.

* Eye irritation properties

No information is available on the specific concentration of tetryl at which eye irritation begins; however, tetryl dust is known to cause eye irritation.

EXPOSURE LIMITS

The current Occupational Safety and Health Administration (OSHA) permissible exposure limit (PEL) for tetryl is 1.5 milligram per cubic meter (mg/m³) 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-A]. The National Institute for Occupational Safety and Health (NIOSH) has not issued a recommended exposure limit (REL) for tetryl; however, NIOSH concurs with the PEL established for this substance by OSHA [NIOSH 1988]. The American Conference of Governmental Industrial Hygienists (ACGIH) has assigned tetryl a threshold limit value (TLV) of 1.5 mg/m³ as a TWA for a normal 8-hour workday and a 40-hour workweek. The ACGIH has also assigned tetryl a "Skin" notation [ACGIH 1991, p. 35]. The ACGIH limit is based on the risk of systemic effects associated with exposure to tetryl [ACGIH 1986, p. 568.1(88)].

HEALTH HAZARD INFORMATION

* Routes of exposure

Exposure to tetryl can occur via inhalation, ingestion, eye or skin contact, and absorption through the skin.

* Summary of toxicology

1. Effects on Animals: Tetryl is toxic to the lungs, kidneys, and livers of experimental animals. The lowest lethal subcutaneous dose in dogs is 5000 mg/kg, and rabbits given 3 doses of tetryl (1000 mg/kg in milk by stomach tube) died [ACGIH 1986, p. 568.1(88)]. Administered subcutaneously to dogs and rabbits in lethal doses, tetryl caused inflammation at the site of injection, toxic degeneration of the kidneys, and, in dogs, necrotic changes and severe fatty degeneration of the liver [ACGIH 1986, p. 568.1(88)]. Several of the exposed animals showed pulmonary edema at autopsy [ACGIH 1986, p. 568.1(88)].

2. Effects on Humans: Tetryl is a potent skin sensitizer, a respiratory sensitizer, and an irritant of the skin and upper respiratory tract in humans. Tetryl is also toxic to the liver and blood on chronic exposure. Initially, tetryl produces acute irritation of the nasal and pharyngeal mucous membranes, with coughing and nosebleeds; however, in some instances, these effects may not occur until as late as the third month of workplace exposure [ACGIH 1986, p. 568.1(88)]. Irritation may progress to itching, swelling, redness, and edema of the eyelids, nasal folds, cheeks and neck; papules and vesicles may also develop. The severest form of sensitization dermatitis may involve massive generalized edema with partial obstruction of the trachea caused by swelling of the tongue [Hathaway, Proctor, Hughes, and Fischman 1991, p. 541]. Most of these effects occur between the 10th and 20th days of exposure, and removal from exposure leads to rapid abatement of mild symptoms and, after 3 to 10 days, disappearance of physical signs [Hathaway, Proctor, Hughes, and Fischman 1991, p. 541]. In some workers, exposure to tetryl dust has caused asthma-like symptoms of severe coughing; in such cases, removal from exposure is necessary [ACGIH 1986, p. 568.1(88)]. Chronic exposure to unspecified concentrations of tetryl causes systemic poisoning that is manifested as digestive disorders, chronic hepatitis, and central nervous system irritation [Hathaway, Proctor, Hughes, and Fischman 1991, p. 541]. Anemia of either the marrow depression or deficiency type has also been observed in chronically exposed workers [Hathaway, Proctor, Hughes, and Fischman 1991, p. 541]. Tetryl has been reported to cause irreversible liver damage and death following heavy exposure; no cases of systemic poisoning have been reported at concentrations below 1.5 mg/m³ [Hathaway, Proctor, Hughes, and Fischman 1991, p. 541].

* Signs and symptoms of exposure

1. Acute exposure: The signs and symptoms of acute exposure to tetryl include redness and inflammation of the eyes and eyelids, runny nose, nosebleeds, yellowing of the skin and hair, headache, dry cough, bronchial spasms, wheezing, and pruritus, erythema, and edema of the skin.

2. Chronic exposure: The signs and symptoms of chronic exposure to tetryl include loss of appetite, abdominal pain, anemia, vomiting, weight loss, insomnia, mental excitation, exaggerated reflexes, jaundice, enlarged and tender liver, elevated liver enzymes, and blood, pus, or protein in the urine.

* Emergency procedures:

In the event of an emergency, the rescuer should don appropriate personal protective equipment, remove the victim from further exposure, send for medical assistance, and initiate the following emergency procedures:

1. Eye exposure: If tetryl dust gets into the eyes, immediately flush the eyes with large amounts of water for a minimum of 15 minutes, lifting the lower and upper lids occasionally. If irritation develops, get medical attention as soon as possible.

2. Skin exposure: If tetryl dust contacts the skin, the contaminated skin should be washed with soap and water. An indicator soap that contains 10 percent potassium sulfite turns red on contact with tetryl and can be used to ensure that all tetryl is removed from the skin. If irritation or sensitization develops, get medical attention.

3. Inhalation: If tetryl dust is inhaled, move the victim at once to fresh air and get medical care as soon as possible. If the victim is not breathing, perform cardiopulmonary resuscitation; if breathing is difficult, give oxygen. Keep the victim warm and quiet until medical help arrives.

4. Ingestion: If tetryl is ingested, give the victim several glasses of water to drink and then induce vomiting by having the victim touch the back of the throat with the finger or by giving syrup of ipecac as directed on the package. Do not force an unconscious or convulsing person to drink liquids or to vomit. Get medical help immediately. Keep the victim warm and quiet until medical help arrives.

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 tetryl and lead to worker exposures to this substance:

* Use in explosives as an intermediary detonating agent and as a booster charge
* Use as a chemical indicator

Methods that are effective in controlling worker exposures to tetryl, depending on the feasibility of implementation, are

* Process enclosure,
* Local exhaust ventilation,
* General dilution ventilation, and
* Personal protective equipment.

The following publications are good sources of information on control methods:

1. ACGIH [1986]. Industrial ventilation--a manual of recommended practice. 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 MONITORING

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 monitoring 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 period 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 tetryl, 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 a history of allergies and on the function and integrity of the eyes, respiratory tract, liver, kidneys, and skin. Medical monitoring for respiratory disease should be conducted using the principles and methods recommended by NIOSH and 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 tetryl 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, respiratory tract, liver, kidneys, or skin.

* Periodic medical examinations and biological monitoring

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 tetryl exposure. The interviews, examinations, and medical screening tests should focus on identifying the adverse effects of tetryl on the eyes, respiratory tract, liver, kidneys, or skin. Current health status should be compared with the baseline health status of the individual worker or with expected values for a suitable reference population.

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 tetryl.

* Medical examinations recommended at the time of job transfer or termination

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.

WORKPLACE MONITORING AND MEASUREMENT PROCEDURES

Determination of a worker's exposure to airborne tetryl is made using a mixed cellulose ester filter (0.8 micron). Samples are collected at a maximum flow rate of 1.5 liter per minute until a maximum air volume of 100 liters is collected. The filter is then treated with N,N-diethylethanolamine to extract the tetryl. Analysis is conducted by colorimetry using a spectrophotometer. This method has a sampling and analytical error of 0.11 over the range of 0.882 to 4.51 mg/m³ and is described in NIOSH Method No. S225 [NIOSH 1977].

PERSONAL HYGIENE PROCEDURES

If tetryl contacts the skin, workers should wash the affected areas immediately with soap and water. An indicator soap should be used to verify that decontamination is complete.

Clothing contaminated with tetryl 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 tetryl, particularly its potential to cause skin and respiratory irritation.

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

Workers should not eat, drink, use tobacco products, or apply cosmetics in areas where tetryl is handled, processed, or stored.

STORAGE

Tetryl should be stored in a suitable explosives magazine or in a cool, dry, well-ventilated area in tightly sealed containers that are labeled in accordance with OSHA's Hazard Communication Standard. Tetryl or solutions containing tetryl should be kept in the dark. Containers of tetryl should be protected from friction, shock, and physical damage and should be stored separately from explosives, oxidizable materials (e.g., hydrazine and trioxygen difluoride), heat, sparks, and open flame. Because empty containers of tetryl may still hold product residues, they should be handled appropriately.

SPILLS

In the event of a spill involving tetryl, 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:

1. Do not touch the spilled material.

2. Notify safety personnel.

3. Remove all sources of heat and ignition.

4. Ventilate potentially explosive atmospheres.

5. Do not sweep or burn the spilled material unless an explosives expert is present to supervise this operation.

EMERGENCY PLANNING, COMMUNITY RIGHT-TO-KNOW, AND HAZARDOUS WASTE

MANAGEMENT REQUIREMENTS

The Environmental Protection Agency's (EPA's) regulatory requirements for emergency planning, community right-to-know, and hazardous waste management may vary over time. Users are therefore advised to determine periodically whether new information is available.

* Emergency planning requirements

Tetryl is not subject to EPA emergency planning requirements under the Superfund Amendments and Reauthorization Act (SARA) (Title III).

* Reportable quantity requirements (releases of hazardous substances)

Employers are not required by the emergency release notification provisions of the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) to notify the National Response Center of an accidental release of tetryl; there is no reportable quantity for this substance.

* Community right-to-know requirements

Employers are not required by Section 313 of the Superfund Amendments and Reauthorization Act (SARA) to submit a Toxic Chemical Release Inventory form (Form R) to EPA reporting the amount of tetryl 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), EPA has specifically listed many chemical wastes as hazardous. Although tetryl is not specifically listed as a hazardous waste under RCRA, EPA requires employers to treat any waste as hazardous if it exhibits any of the characteristics discussed above.

Providing more information about the removal and disposal of specific chemicals is beyond the scope of this guideline. EPA, U.S. Department of Transportation, 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 (202) 382-3000 (in Washington, D.C.) 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 tetryl 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 emergency situations. If the use of respirators is necessary, the only respirators permitted are those 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. Such a program must include respirator selection (see Table 1), an evaluation of the worker's ability to perform the work while wearing a respirator, the regular training of personnel, 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 NIOSH Respirator Decision Logic and the NIOSH Guide to Industrial Respiratory Protection.

Table 1 lists the respiratory protection that NIOSH recommends for workers exposed to tetryl. The recommended protection may vary over time because of changes in the exposure limit for tetryl or in respirator certification requirements. Users are therefore advised to determine periodically whether new information is available.

PERSONAL PROTECTIVE EQUIPMENT

Protective clothing should be worn to prevent repeated or prolonged skin contact with tetryl. Chemical protective clothing should be selected on the basis of available performance data, manufacturers' recommendations, and evaluation of the clothing under actual conditions of use. No reports have been published on the resistance of various protective clothing materials to tetryl permeation. If permeability data are not readily available, protective clothing manufacturers should be requested to provide information on the best chemical protective clothing for workers to wear when they are exposed to tetryl.

If tetryl is dissolved in an organic solvent, the permeation properties of both the solvent and the mixture must be considered when selecting personal protective equipment and clothing.

Safety glasses, goggles, or faceshields should be worn during operations in which tetryl might contact the eyes (e.g., through dust particles). Eyewash fountains and emergency showers should be available within the immediate work area whenever the potential exists for eye or skin contact with tetryl. Contact lenses should not be worn if the potential exists for tetryl exposure.

REFERENCES

ACGIH [1986]. Documentation of the threshold limit values and biological exposure indices. 5th edition. Cincinnati, OH: American Conference of Governmental Industrial Hygienists.

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

[CFR]. Code of Federal regulations. Title 29 (Department of Labor), Parts 1910.134, 1910.1000, and 1910.1200. Washington, DC: U.S. Government Printing Office, Office of the Federal Register.

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

NIOSH [1977]. NIOSH manual of analytical methods. 2nd edition. Cincinnati, OH: U.S. Department of Health and Human Services, Public Health Service, Centers for Disease Control, National Institute for Occupational Safety and Health.

NIOSH [1988]. Testimony of the National Institute for Occupational Safety and Health on the Occupational Safety and Health Administration's proposed rule: 29 CFR 1910, Docket No. H-020, August 2, 1988. NIOSH policy 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.

BIBLIOGRAPHY

ACGIH [1986]. Documentation of the threshold limit values and biological exposure indices. 5th edition. Cincinnati, OH: American Conference of Governmental Industrial Hygienists.

Bretherick L [1985]. Handbook of reactive chemical hazards. 3rd edition. London, England: Butterworths.

Clayton G, Clayton F [1981-1982]. Patty's industrial hygiene and toxicology. 3rd revised edition. New York, NY: John Wiley & Sons.

[CFR]. Code of Federal regulations. Title 29 (Department of Labor), Parts 1910.134, 1910.1000, and 1910.1200. Washington, DC: U.S. Government Printing Office, Office of the Federal Register.

[CFR]. Code of Federal regulations. Title 40 (Protection of Environment). Washington, DC: U.S. Government Printing Office, Office of the Federal Register.

[CFR]. Code of Federal regulations. Title 49 (Department of Transportation). Washington, D.C.: U.S. Government Printing Office, Office of the Federal Register.

DOT [1987]. 1987 Emergency response guidebook, guide 46. Washington, DC: U.S. Department of Transportation, Office of Hazardous Materials Transportation, Research and Special Programs Administration.

Hawley's condensed chemical dictionary [1987]. Sax NI, Lewis RJ. 11th edition. New York, NY: Van Nostrand Reinhold Company.

HSDB [1992]. Tetryl. Bethesda, MD: The Hazardous Substances Data Bank, National Library of Medicine.

ITI [1986]. Toxic and hazardous industrial chemicals safety manual. Tokyo, Japan: International Technical Information Institute.

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

NIOSH [1981]. NIOSH/OSHA occupational health guidelines. 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. 81-123.

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]. 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.

Parmeggiani L [1983]. Encyclopedia of occupational health and safety. 3rd revised edition. Geneva, Switzerland: International Labour Organisation.

Proctor NH, Hughes JP [1978]. Chemical hazards of the workplace. Philadelphia, PA: J.B. Lippincott Company.

RTECS [1991]. Tetryl. Bethesda, MD: Registry of Toxic Effects of Chemical Substances, National Library of Medicine.

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

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

Weast RC [1984]. CRC handbook of chemistry and physics. 64th edition. Boca Raton, FL: CRC Press, Inc.

* The OSHA PEL is 1.5 mg/m³ as an 8-hour TWA. No NIOSH REL has been issued.
** Only NIOSH/MSHA-approved equipment should be used. Also note the following:

1. Respirators accepted for use at higher concentrations may be used at lower concentrations; respirators must not, however, be used at concentrations higher than those for which they are approved.

2. Air-purifying respirators may not be used in oxygen-deficient atmospheres or in airborne concentrations that are immediately dangerous to life or health (IDLH).

3. No threshold concentration for eye irritation is reported. Therefore, half-mask respirators can be used. If workers experience irritation, they should be provided with respirators that have hoods and that provide equal or better protection than quarter- or half-mask respirators.