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 This information may be superseded by new developments in the field of industrial hygiene.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

INTRODUCTION

This guideline summarizes pertinent information about hexachloronaphthalene 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 Recommendations may be superseded by new developments in these fields; readers are therefore advised to regard these recommendations as general guidelines and to determine whether new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(10)H(2)Cl(6)

* Structure

(For Structure, see paper copy)

* Synonyms

Halowax 1014, halowax

* Identifiers

1. CAS No.: 1335-87-1

2. RTECS No.: QJ7350000

3. Specific DOT number: None

4. Specific DOT label: None

* Appearance and odor

Hexachloronaphthalene is a white to light yellow, nonflammable solid with an aromatic odor. In commercial form, it generally consists of a mixture of chlorinated naphthalenes.

CHEMICAL AND PHYSICAL PROPERTIES

* Physical data

1. Molecular weight: 335

2. Boiling point (at 760 mm Hg): 343-388 degrees C (650-730 degrees F)

3. Specific gravity (water = 1): 1.78 at 25 degrees C (77 degrees F)

4. Vapor density: 11.6

5. Melting point: 137 degrees C (279 degrees F)

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

7. Solubility: Insoluble in water, soluble in organic solvents.

8. Evaporation rate: Data not available.

* Reactivity

1. Conditions contributing to instability: None reported.

2. Incompatibilities: Contact between hexachloronaphthalene and strong oxidizing agents, acids or acid fumes should be avoided.

3. Hazardous decomposition products: Toxic gases and vapors (such as hydrogen chloride, phosgene, and carbon monoxide) may be released in a fire involving hexachloronaphthalene.

4. Special precautions: None reported.

* Flammability

Hexachloronaphthalene is not combustible.

1. Flash point: Not applicable.

2. Autoignition 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.

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

EXPOSURE LIMITS

* OSHA PEL

The current Occupational Safety and Health Administration (OSHA) permissible exposure limit (PEL) for hexachloronaphthalene is 0.2 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 hexachloronaphthalene of 0.2 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 hexachloronaphthalene [NIOSH 1992].

* ACGIH TLV

The American Conference of Governmental Industrial Hygienists (ACGIH) has assigned hexachloronaphthalene a threshold limit value (TLV) of 0.2 mg/m(3)) as a TWA for a normal 8-hour workday and a 40-hour workweek. The ACGIH also assigns a "Skin" notation to hexachloronaphthalene [ACGIH 1994, p. 23].

* Rationale for Limits

The NIOSH limit is based on the risk of toxic effects to the liver and skin [NIOSH 1992].

The ACGIH limit is based on the risk of toxic effects to the liver and skin [ACGIH 1991, p. 745].

HEALTH HAZARD INFORMATION

* Routes of Exposure

Exposure to hexachloronaphthalene can occur through inhalation, ingestion, eye or skin contact, and absorption through the skin, eyes, and mucous membranes [Sittig 1991, p. 879].

* Summary of toxicology

1. Effects on Animals: Ingestion of hexachloronaphthalene or inhalation of its vapors causes severe liver injury, which is characterized as acute yellow atrophy or subacute necrosis [Clayton and Clayton 1982; Parmeggiani 1983]. Rats exposed daily to the vapors of a mixture of penta- and hexachloronaphthalene at an average concentration of 1.16 mg/m(3) exhibited definite liver injury; at a concentration of 8.88 mg/m(3), there was some mortality, poor growth, and severe liver injury (jaundice, marked fatty degeneration, and centrilobular necrosis) [Clayton and Clayton 1982; Hathaway et al. 1991]. Rats fed a mixture of penta- and hexachloronaphthalene for one month at a dose of 3 g/day had a mortality rate of 90 percent; all animals became ill and experienced weight loss and serious liver damage. When a mixture of tetra- and hexachloronaphthalene was administered to rats in a dietary dose of 0.5 mg/day for 2 months, some sickness, some mortality, and definite liver injury were observed [Clayton and Clayton 1982]. Repeated ingestion of hexachloronaphthalene produced hyperkeratosis of the skin as well as liver injury and other systemic effects in cattle. However, because tissues of the mouth, cheek, and neck were also affected, it is suspected that some chloronaphthalenes may act by direct contact with the mouth and skin [Clayton and Clayton 1982]. The dermal LD(50) for rabbits is 32,000 mg/kg [ACGIH 1991]. Application to the rabbit skin produced epithelial hyperplasia, followed by inflammatory and degenerative changes, and, finally, regenerative processes [Clayton and Clayton 1982].

2. Effects on Humans: In humans, hexachloronaphthalene is a hepatotoxin and a chloracnegen. Repeated exposure to airborne concentrations of between 1 and 2 mg/m(3) mixed penta- and hexachloronaphthalene produced fatalities from acute yellow atrophy of the liver; other workers experienced jaundice, nausea, indigestion, and weight loss [Hathaway et al. 1991; ACGIH 1991]. The most commonly observed problem from the occupational use and handling of the chlorinated naphthalenes is chloracne, which usually occurs as a result of long-term contact with hexachloronaphthalene, or of much shorter contact of the skin with the hot vapor. The chloracne is usually slow to appear, and normalcy may not return for months [Clayton and Clayton 1982; Hathaway et al. 1991]. All chloronaphthalenes are capable of being absorbed through the intact skin, and they have a photosensitizing action dermally [Parmeggiani 1983].

* Signs and symptoms of exposure

1. Acute exposure: Acute exposure to hexachloronaphthalene causes pruritus, eye irritation, headache, fatigue, vertigo, and nausea [Parmeggiani 1983].

2. Chronic exposure: Chronic exposure to hexachloronaphthalene can cause an enlarged liver and acne-form lesions on the face, ears, neck, shoulders, arms, chest, abdomen, and scrotum. Jaundice, nausea, indigestion, and weight loss are also symptoms of hexachloronaphthalene poisoning [Parmeggiani 1983; Hathaway et al. 1991].

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 hexachloronaphthalene and lead to worker exposures to this substance:

* The manufacture and transportation of hexachloronaphthalene

* Use in manufacture (pouring, dipping and peeling) of electric wire, cables, and equipment to be used as insulating material

* Use as an additive in cutting oils and extreme-pressure lubricants

* Used as supports for storage batteries; as a coating in foundry use; in production of electric condensers

Methods that are effective in controlling worker exposures to hexachloronaphthalene, 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 hexachloronaphthalene 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 hexachloronaphthalene, 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 and liver.

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 hexachloronaphthalene 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 and liver.

* 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 hexachloronaphthalene exposure. The interviews, examinations, and medical screening tests should focus on identifying the adverse effects of hexachloronaphthalene on the skin or liver. 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 hexachloronaphthalene.

WORKPLACE MONITORING AND MEASUREMENT

Determination of a worker's exposure to airborne hexachloronaphthalene is made using a mixed cellulose ester filter (MCEF) 0.8 microns. Samples are collected at a maximum flow rate of 1 liter/minute until a maximum collection volume of 30 liters is reached. Analysis is conducted by gas chromatography using an electron capture detector (GC/ECD). This method is fully validated and is described in the OSHA Computerized Information System [OSHA 1994].

PERSONAL HYGIENE PROCEDURES

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

Clothing contaminated with hexachloronaphthalene 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 hexachloronaphthalene.

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

STORAGE

Hexachloronaphthalene 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 hexachloronaphthalene should be protected from physical damage and contact with acid fumes, and should be stored separately from strong oxidizing agents or acids.

SPILLS AND LEAKS

In the event of a spill or leak involving hexachloronaphthalene, persons not wearing protective equipment and full-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, isolate area, and stay upwind.

2. Ventilate atmosphere to reduce concentration.

3. 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. Wet mopping or vacuuming (with appropriate filter) may minimize dust generation.

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

5. For large liquid spills, build dikes far ahead of the spill to contain the hexachloronaphthalene 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

Hexachloronaphthalene 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].

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 hexachloronaphthalene; there is no reportable quantity for this substance.

* 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 hexachloronaphthalene per calendar year or otherwise use 10,000 pounds or more of hexachloronaphthalene 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 hexachloronaphthalene 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 hexachloronaphthalene 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 hexachloronaphthalene 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 hexachloronaphthalene. 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 hexachloronaphthalene. There are no published reports on the resistance of various materials to permeation by hexachloronaphthalene.

To evaluate the use of PPE materials with hexachloronaphthalene, 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 hexachloronaphthalene.

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.

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

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

Genium [1992]. Material safety data sheet No. 799. 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.

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.

NIOSH [1991]. Registry of toxic effects of chemical substances: Hexachloronaphthalene. 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 [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: Hexachloronaphthalene. 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 [1994]. 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.

NJDH [1985]. Hazardous substance fact sheet: Hexachloronaphthalene. Trenton, NJ: New Jersey Department of Health.

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

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

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

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.

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