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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 III and IV 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 This information may be superseded by new developments in the field of industrial hygiene.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.

Introduction | Recognition | Evaluation | Controls | References

Introduction

This guideline summarizes pertinent information about chlorine trifluoride 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 Recommendations may be superseded by new developments in these fields; readers are therefore advised to regard these recommendations as general guidelines and to determine whether new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.

Recognition

SUBSTANCE IDENTIFICATION

* Formula
ClF(3)

* Structure
Data not available.

* Synonyms
Chlorine fluoride, chlorotrifluoride, chlorine fluoride (CL2F6), chlorine fluoride (CLF3), chlorine trifluoride (CLF3)

* Identifiers
  1. CAS No.: 7790-91-2
  2. RTECS No.: FO2800000
  3. DOT UN: 1749 44
  4. DOT label: Poison gas, oxidizer, corrosive
* Appearance and odor

Chlorine trifluoride in a gas form is colorless, corrosive, and has a sweet but suffocating odor. In its liquid form it is pale-green, and is white in its solid form. Although no odor threshold has been reported, concentrations above 10 parts per million (ppm) parts of air are reportedly intolerable.

CHEMICAL AND PHYSICAL PROPERTIES

* Physical data
  1. Molecular weight: 92.46
  2. Boiling point (at 760 mm Hg): 11.75 degrees C (53.15 degrees F)
  3. Specific gravity: 1.77 at 13 degrees C (55.4 degrees F)
  4. Vapor density: 3.14
  5. Melting point: -76.34 degrees C (-105.41 degrees F)
  6. Vapor pressure at 20 degrees C (68 degrees F): Greater than 760 mm Hg
  7. Solubility: Insoluble and explodes on contact with water.
  8. Evaporation rate: Data not available.
* Reactivity
  1. Conditions contributing to instability: Heat; chlorine trifluoride decomposes above 220 degrees C (428 degrees F) and may rupture the container.
  2. Incompatibilities: Contact of chlorine trifluoride with most combustible materials will ignite spontaneously. The exceptions are dry, highly fluorinated polymers such as Teflon and Kel-F, the metals used in storage containers (monel, copper, and stainless steel) or gaskets (teflon), nitrogen gas or air, and the inert gases (neon, etc.). Violent reactions, including explosions, may occur when chlorine trifluoride is in contact with water, ice, or silicon- containing compounds (sand, glass, and asbestos). It is incompatible with oil, grease, reducing agents, organic compounds, fuels and combustibles, and many metals and metal oxides, especially if these are in powder form.
  3. Hazardous decomposition products: Toxic gases and vapors such as chlorine, fluorine, and hydrogen fluoride may be released when chlorine trifluoride decomposes.
  4. Special precautions: Chlorine trifluoride will ignite in contact with incompatible chemicals without a spark or ignition source present (it is a hypergolic material).
* Flammability

Chlorine trifluoride is non-flammable. The National Fire Protection Association has assigned a flammability rating of 0 (no fire hazard) to chlorine trifluoride.
  1. Flash point: Not applicable.
  2. Auto-ignition temperature: Not applicable.
  3. Flammable limits in air: Not applicable.
  4. Extinguishant: Use an extinguishant that is suitable for the materials involved in the surrounding fire. Do not use water, or if water must be used, use in excessive amounts.
Fires involving chlorine trifluoride should be fought upwind from the maximum distance possible. Keep unnecessary people away; isolate the hazard area and deny entry. Violent reactions may occur on contact with water. 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 chlorine trifluoride 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. Firefighters should wear a full set of protective clothing and self-contained breathing apparatus when fighting fires involving chlorine trifluoride.

EXPOSURE LIMITS

* OSHA PEL

The current Occupational Safety and Health Administration (OSHA) permissible exposure limit (PEL) for chlorine trifluoride is 0.1 ppm milligrams per cubic meter (mg/m(3)) of air) as a ceiling limit. A worker's exposure to chlorine trifluoride shall at no time exceed this ceiling level [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 chlorine trifluoride of 0.1 ppm (0.4 mg/m(3)) as a ceiling limit [NIOSH 1992].

* ACGIH TLV

The American Conference of Governmental Industrial Hygienists (ACGIH) has assigned has assigned chlorine trifluoride a ceiling limit value of 0.1 ppm (0.38 mg/m(3)), which should not be exceeded during any part of the working exposure [ACGIH 1994, p. 15].

* Rationale for Limits

The NIOSH limit is based on the risk of severe eye, skin, and respiratory irritation [NIOSH 1992].

The ACGIH limit is based on the risk of serious injury [ACGIH 1991, p.

Evaluation

HEALTH HAZARD INFORMATION

* Routes of Exposure

Exposure to chlorine trifluoride can occur through inhalation, ingestion, and eye or skin contact [Sittig 1991, p. 380].

* Summary of toxicology
  1. Effects on Animals: Chlorine trifluoride is a severe irritant of the respiratory tract and skin in animals [Hathaway et al. 1991]. The one hour inhalation LC(50) in monkeys is 230 ppm and 299 ppm in rats[NIOSH 1995]. The exposure of rats to 800 ppm of chlorine trifluoride for 15 minutes resulted in the death of all rats, but nearly all survived exposure at this level for 13 minutes. The effects of exposure included mucosal inflammation, tearing, corneal ulcers, and severe corrosive burns of the skin. Exposure to 480 ppm for 40 minutes or to 96 ppm for 3.7 hours was fatal. All experimental animals exposed to 96 ppm for 3.7 hours exhibited pulmonary edema and marked irritation of the bronchial mucosa [Hathaway et al. 1991]. In chronic inhalation studies, dogs and rats were exposed to 1.17 ppm chlorine trifluoride for 6 hours daily, 5 days/week for 6 months. The two dogs experienced coughing, sneezing, salivation, difficulty in breathing, and nasal frothing. After 2 months, the dogs had recurrent bouts of pneumonia; one dog died at 115 days. In rats, these symptoms were not as pronounced, but after several weeks of exposure, a bloody nasal and eye discharge was observed. Six of the 20 rats died during the study [ACGIH 1991].
  2. Effects on Humans: Effects of exposure to chlorine trifluoride in humans have not been reported [Hathaway et al. 1991]. However, based on animal studies, inhalation can be expected to result in delayed and progressive irritation of the respiratory tract, chemical pneumonitis, and pulmonary edema. Contact with the eyes may cause tearing, irritation, and corneal ulcerations. Permanent loss of vision can occur [Genium 1990]. The liquid is severely corrosive to the skin and eyes. Exposure to solutions containing more than 50% of the agent produces immediate burning, erythema, and tissue damage. Exposure to solutions ranging from 20% to 50% of the agent results in pain and erythema which may be delayed up to 1 to 8 hours. Exposure to solutions containing less than 20% of the agent causes erythema and pain immediately or delayed up to 24 hours after exposure [NLM 1995]. The fluoride ion acts as a direct cellular poison by interfering with calcium metabolism and enzyme mechanisms, and hypocalcemia may occur following oral or extensive dermal exposure [NLM 1995]. Chronic exposure to low concentrations of chlorine trifluoride may cause fluorosis.
* Signs and symptoms of exposure
  1. Acute exposure: No signs or symptoms of acute exposure to chlorine trifluoride have been reported in humans.
  2. Chronic exposure: No signs or symptoms of chronic exposure to chlorine trifluoride have been reported in humans.
EMERGENCY MEDICAL PROCEDURES

* Emergency medical procedures: [NIOSH to supply]

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 chlorine trifluoride and lead toworker exposures to this substance:
  • The manufacture and transportation of chlorine trifluoride
  • Use as a fluorinating agent in organic and inorganic chemical synthesis; used in the separation of uranium isomers
  • Use as a cutting agent for well castings in oil well drilling and as a cutting oil for high-temperature metals
  • Use as a rocket fuel oxidizer and as an igniter and propellant in rockets and liquid propellant engines; used as an incendiary
  • Use in nuclear reactions fuel processing; used as a pyrolysis inhibitor for fluorocarbon polymers
Methods that are effective in controlling worker exposures to chlorinetrifluoride, 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

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 chlorine trifluoride 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, periodically during the term of employment, and (3) at the time of job transfer or termination.

* Pre-placement medical evaluation

Before a worker is placed in a job with a potential for exposure to chlorine trifluoride, 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, and respiratory system. Medical surveillance for respiratory disease should be conducted using the principles and methods recommended by the American Thoracic Society.

A pre-placement medical evaluation is recommended to assess medical conditions that may be aggravated or may result in increased risk when a worker is exposed to chlorine trifluoride 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, or respiratory 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 chlorine trifluoride exposure. The interviews, examinations, and medical screening tests should focus on identifying the adverse effects of chlorine trifluoride on the skin, eyes, or respiratory 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. No biological monitoring test acceptable for routine use has yet been developed for chlorine trifluoride.

WORKPLACE MONITORING AND MEASUREMENT

Determination of a worker's exposure to airborne chlorine trifluoride is made using a midget fritted glass bubbler (MFGB) containing 10 milliliters of 0.01 N sodium hydroxide. Samples are collected at a recommended flowrate of 0.1 liter/minute (ceiling) until a recommended collection volume of liters is reached. Analysis is conducted by ion specific electrode (ISE). This method is described in the OSHA Computerized InformationSystem and is not yet validated.

Controls

PERSONAL HYGIENE PROCEDURES

If chlorine trifluoride contacts the skin, workers should flush the affected areas immediately with plenty of water for at least 15 minutes.

Clothing contaminated with chlorine trifluoride 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 chlorine trifluoride, particularly its potential for causing severe skin and eye irritation and tissue burns.
A worker who handles chlorine trifluoride 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 chlorine trifluoride or a solution containing chlorine trifluoride is handled, processed, or stored.

STORAGE

Chlorine trifluoride 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 chlorinetrifluoride should be protected from physical damage and should be stored separately from most combustible materials, water, ice, or silicon-containing compounds (sand, glass, and asbestos), oil, grease, reducing agents, organic compounds, fuels and combustibles, and many metals and metal oxides.

SPILLS AND LEAKS

In the event of a spill or leak involving chlorine trifluoride, 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 combustibles from the spilled material (wood, paper, oil, etc.)
  3. Do not touch the spilled material; stop the leak if it is possible to do so without risk.
  4. Use water spray to reduce vapors; do not get water inside container.
  5. For small liquid spills, flush areas with flooding amounts of water.
  6. For large liquid spills, build dikes far ahead of the spill to contain the chlorine trifluoride 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

Chlorine trifluoride is not subject to EPA emergency planning requirements under the Superfund Amendments and Reauthorization ActSARA) (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

Employers are not required by the emergency release notification provisions in 40 CFR Part 355.40 to notify the National Response Center of an accidental release of chlorine trifluoride; there is no reportable quantity for this substance.

* Community right-to-know requirements

Employers are not required by EPA in 40 CFR Part 372.30 to submit a Toxic Chemical Release Inventory form (Form R) to EPA reporting the amount of chlorine trifluoride 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 chlorine trifluoride 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 chlorine trifluoride 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 chlorine trifluoride. 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 chlorine trifluoride. There are no published reports on the resistance of various materials to permeation by chlorine trifluoride.

To evaluate the use of PPE materials with chlorine trifluoride, 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 chlorine trifluoride.

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.

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

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

DOT [1993]. 1993 Emergency response guidebook, guide 44. Washington, DC: U.S. Department of Transportation, Office of Hazardous Materials Transportation, Research and Special Programs Administration.

Genium [1990]. Material safety data sheet No. 125. Schenectady, NY: Genium Publishing Corporation.

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.

Lide DR [1993]. CRC handbook of chemistry and physics. 73rd ed. Boca Raton, FL: CRC Press, Inc.

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 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 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 [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 [1995]. Registry of toxic effects of chemical substances: Chlorine trifluoride. 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.

NJDH [1986]. Hazardous substance fact sheet: Chlorine trifluoride. Trenton, NJ: New Jersey Department of Health.

NLM [1995]. Hazardous substances data bank: Chlorine trifluoride. Bethesda, MD: National Library of Medicine.

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

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.

Introduction | Recognition | Evaluation | Controls | References