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 This information may be superseded by new developments in the field of industrial hygiene.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 ARSENIC, ORGANIC COMPOUNDS (as As)

INTRODUCTION

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 Recommendations may be superseded by new developments in these fields; readers are therefore advised to regard these recommendations as general guidelines and to determine whether new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

APPLICABILITY

The general guidelines contained in this document apply to all of the organic compounds of arsenic. Examples of such compounds include arsanilic acid and cacodylic acid. For illustrative purposes, the physical and chemical properties of these organic arsenic compounds are presented below.

SUBSTANCE IDENTIFICATION

Arsanilic acid

* Formula

C(6)H(8)AsNo(3)

* Structure

(For Structure, see paper copy)

* Synonyms

p-aminobenzenearsonic acid, aminophenylarsine acid, atoxylic acid, antoxylic acid, p-arsanilic acid

* Identifiers

1. CAS No.: 98-50-0

2. RTECS No.: CF7875000

3. Specific DOT number: None

4. Specific DOT label: None

* Appearance and odor

Arsanilic acid is a white crystalline powder that is essentially odorless. It may also be in the form of needles.

CHEMICAL AND PHYSICAL PROPERTIES

* Physical data

1. Molecular weight: 217

2. Boiling point: Decomposes.

3. Specific gravity: Data not available.

4. Vapor density: Data not available.

5. Melting point: 232 degrees C (450 degrees F)

6. Vapor pressure: Data not available.

7. Solubility: Very soluble in hot water; slightly soluble in cold water, alcohol, and acetic acid; insoluble in acetone, benzene, ether, and chloroform.

8. Evaporation rate: Data not available.

Cacodylic acid

* Formula

C(2)H(7)AsO(2)

* Structure

((CH(3))(2)AsOOH)

* Synonyms

Dimethylarsinic acid, hydroxydimethylarsine oxide, phytar, DMAA, chexmate, ansar

* Identifiers

1. CAS No.: 75-60-5

2. RTECS No.: CH7525000

3. DOT UN number: 1572 53

4. DOT label: Poison

* Appearance and odor

Cacodylic acid is a colorless, odorless, and hygroscopic crystalline solid. It is also commercially available in the form of soluble concentrates. Water solutions of cacodylic acid are sometimes dyed blue.

CHEMICAL AND PHYSICAL PROPERTIES

* Physical data

1. Molecular weight: 138.01

2. Boiling point: Data not available.

3. Specific gravity: Data not available.

4. Vapor density: Data not available.

5. Melting point: 195 to 196 degrees C (383 to 385 degrees F)

6. Vapor pressure: Data not available.

7. Solubility: Very soluble in alcohol; soluble in water and acetic acid; practically insoluble in ether.

8. Evaporation rate: Data not available.

* Reactivity

1. Conditions contributing to instability: Vary depending on the specific organic arsenic compound.

2. Incompatibilities: Vary depending on the specific organic arsenic compound. Arsenic is incompatible with oxidizers such as perchlorates, peroxides, permanganates, chlorates, or nitrates, and strong acids such as hydrochloric, sulfuric, or nitric.

3. Hazardous decomposition products: Vary depending on the specific organic arsenic compound.

4. Special precautions: Vary depending on the specific organic arsenic compound.

* Flammability

The flammability of each organic arsenic compound may vary. Arsenic dust is a slight explosive hazard when exposed to flame.

The National Fire Protection Association has not assigned a flammability rating to arsenic, cacodylic acid, or arsanilic acid.

1. Flash point: Data not available.

2. Autoignition temperature: Data not available.

3. Flammable limits in air: Data not available.

4. Extinguishant: Use an extinguishant that is suitable for the materials involved in the surrounding fire.

Fires involving organic arsenic compounds 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 arsenic, organic compounds.

EXPOSURE LIMITS

* OSHA PEL

The current Occupational Safety and Health Administration (OSHA) permissible exposure limit (PEL) for organic compounds arsenic (as As) is 0.5 milligrams per cubic meter (mg/m(3)) of air as an 8-hour time-weighted average (TWA) concentration [29 CFR 1910.1000, Table Z-1].

* NIOSH REL

* The National Institute for Occupational Safety and Health has not established a recommended exposure limit for arsenic, organic compounds.

* ACGIH TLV

The American Conference of Governmental Industrial Hygienists (ACGIH) has not assigned organic arsenic compounds a threshold limit value.

HEALTH HAZARD INFORMATION

* Routes of Exposure

Exposure to arsenic, organic compounds can occur through inhalation, ingestion, eye or skin contact, and absorption through the skin.

* Summary of toxicology

1. Effects on Animals: Organic arsenic compounds can be irritants, reproductive toxins, or kidney toxins in experimental animals. The toxicity of arsenic compounds vary greatly with the chemical form and oxidation state of the specific chemical involved. Oral LD(50) values in animal studies range from 10 to 2,800 mg/kg, depending on the compound [IARC 1980]. The oral LD(50) in rats for arsanilic acid and cacodylic acid are 216 and 1,350 mg/kg, respectively [Sax and Lewis 1989; Parmeggiani 1983]. Rats receiving oral doses of 2,260 mg/kg of cacodylic acid over a period of 4 weeks showed signs of kidney, ureter, and bladder effects as well as weight loss [NIOSH 1995]. Long-term dietary feeding of 50 ppm monosodium methanearsonic acid (equivalent to a dose of 1.5 mg arsenic per kilogram body weight) of rabbits produced toxic hepatitis [IARC 1987]. In mice, oral doses of 3 gm/kg of cacodylic acid on days 8 through 12 of the pregnancy produced effects on the newborns (effects not further specified) [NIOSH 1995]. A study on the developmental effects of cacodylic acid in mice reported positive results following oral administration a 1,600 mg/kg dose on the eighth day of pregnancy [NIOSH 1995]. The effects noted were developmental abnormalities involving the musculoskeletal system. The International Agency for Research on Cancer (IARC) reviewed the data on the carcinogenicity of organic arsenicals to animals and determined that inadequate data was available to make firm conclusions regarding the carcinogenicity of these compounds. Arsenic was found to have limited evidence for carcinogenicity to animals [IARC 1987].

2. Effects on Humans: Arsenic compounds are irritants, systemic toxins, and carcinogens in humans. Acute exposures to arsenic compounds are considered rare in industry; most poisonings are the result of ingestion of contaminated food and drinks [Hathaway et al. 1991]. The trivalent arsenic compounds are the most toxic to humans. Initial responses to acute poisoning include burning of the lips, constriction of the throat, and dysphagia [Hathaway et al. 1991]. This is followed by excruciating pain in the abdominal region, severe nausea, vomiting, and diarrhea. Toxic effects on the liver, blood-forming organs, both central and peripheral nervous systems, and the cardiovascular system may also occur. Convulsions, coma, and death may follow within 24 hours of severe poisonings [Hathaway et al. 1991]. Acute inhalation exposures to arsenic compounds may result in damage to the mucous membranes of the respiratory system [Parmeggiani 1983]. Severe irritation of the nasal mucosae, larynx, and bronchi have been observed following exposures. In addition, exposed skin may become irritated; cases of dermatitis have been reported following dermal contact with arsenic compounds [Parmeggiani 1983]. Conjunctivitis, visual disturbances, hyperpigmentation of the skin, and perforation of the nasal septum have been described in the literature [Hathaway et al. 1991]. Chronic exposure causes damage to the nervous system, cardiovascular system, and liver [Parmeggiani 1983]. Anemia and leukocytopenia have been reported to occur following chronic exposures to arsenic compounds [Parmeggiani 1983]. Cancers of the skin, lungs, larynx, lymphoid system, and viscera have been identified as potential responses to arsenic poisoning [Hathaway et al. 1991]. IARC has reviewed the available data and considers arsenic to be a Group 1 carcinogen with sufficient evidence of carcinogenicity in humans [IARC 1987].

* Signs and symptoms of exposure

1. Acute exposure: Acute exposures to organic arsenic compounds by ingestion may result in burning lips, throat constriction, abdominal pain, dysphagia, nausea, vomiting, diarrhea, convulsions, coma, and death. Irritation of the respiratory tract, skin, and eyes may result from inhalation exposures.

2. Chronic exposure: Chronic exposure to organic arsenic compounds may result in dermatitis, anemia, leukocytopenia, or the effects associated with several forms of cancer.

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 organic arsenic compounds and lead to worker exposures to these substances:

* The manufacture and transportation of organic arsenic compounds

* Use as herbicides, pesticides, and defoliants

* Use as additives for feed and drinking water for animals

* Use as a preharvest desiccant, sugarcane ripener, soil sterilant, and for timber thinning

* Use in warfare

Methods that are effective in controlling worker exposures to arsenic, organic compounds, 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 arsenic, organic compounds 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 organic arsenic compounds, a licensed health care professional should evaluate and document the worker's baseline health status with thorough medical, environmental, and occupational histories, a physical examination, and physiologic and laboratory tests appropriate for the anticipated occupational risks. These should concentrate on the function and integrity of the eyes, skin, respiratory system, central and peripheral nervous systems, and liver. Medical surveillance for respiratory disease should be conducted using the principles and methods recommended by the American Thoracic Society.

A preplacement medical evaluation is recommended to assess medical conditions that may be aggravated or may result in increased risk when a worker is exposed to organic arsenic compounds at or below the prescribed exposure limit. The health care professional should consider the probable frequency, intensity, and duration of exposure as well as the nature and degree of any applicable medical condition. Such conditions (which should not be regarded as absolute contraindications to job placement) include a history and other findings consistent with diseases of the eyes, skin, respiratory system, central and peripheral nervous systems, or 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 arsenic, organic compounds exposure. The interviews, examinations, and medical screening tests should focus on identifying the adverse effects of organic arsenic compounds on the eyes, skin, respiratory system, central and peripheral nervous systems, 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. Because occupational exposure to organic arsenic compounds 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. Urine levels of arsenic can be measured at the end of the workweek. A biological exposure index (BEI) of 50 micrograms/gram of creatinine should be used to evaluate exposures to organic arsenic compounds.

WORKPLACE MONITORING AND MEASUREMENT

Determination of a worker's exposure to airborne organic arsenic compounds (as As) is made using a PTFE polyethylene-backed membrane filter, 1 micron pore size. Samples are collected at a maximum flow rate of 2.0 liters/minute until a minimum collection volume of 450 liters (or a maximum volume of 960 liters) is reached. Analysis is conducted by ion chromatography using atomic absorption spectroscopy (IC-AAS). This method is described in the OSHA Computerized Information System [OSHA 1994] and is not yet validated. This method is also found in the NIOSH Manual of Analytical Methods (Method No. 5502) [NIOSH 1994].

PERSONAL HYGIENE PROCEDURES

If organic arsenic compounds contacts the skin, workers should flush the affected areas immediately with plenty of water, followed by washing with large amounts of soap and water.

Clothing contaminated with organic arsenic compounds 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 organic arsenic compounds, particularly their potential for causing irritation, and nevous system effects.

A worker who handles organic arsenic compounds 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 organic arsenic compounds or a solution containing organic arsenic compounds is handled, processed, or stored.

STORAGE

Organic arsenic compounds 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 organic arsenic compounds should be protected from physical damage and should be stored separately from oxidizers such as perchlorates, peroxides, permanganates, chlorates, or nitrates, and strong acids such as hydrochloric, sulfuric, or nitric. Specific organic arsenic compounds may have other storage requirements which should be evaluated prior to storage.

SPILLS AND LEAKS

In the event of a spill or leak involving organic arsenic compounds, persons not wearing protective equipment and clothing should be restricted from contaminated areas until cleanup has been completed. The following steps should be undertaken following a spill or leak:

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

2. Notify safety personnel.

3. Ventilate the area of the spill or leak.

4. For small dry spills, collect the spilled material in the most convenient and safe manner possible and deposit it into containers for later disposal or reclamation.

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

6. For large liquid spills, build dikes far ahead of the spill to contain the arsenic, organic compounds 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. In addition, the requirements for specific organic arsenic compounds vary and it is therefore advisable to check the published requirements for the specific compound in use. An example compound (cacodylic acid) is used for the section below only to provide a representative listing of the EPA requirements.

* Emergency planning requirements

Cacodylic acid 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 cacodylic acid is 1 pound. 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 cacodylic acid per calendar year or otherwise use 10,000 pounds or more of cacodylic acid 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 cacodylic acid 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. Cacodylic acid is listed as a hazardous waste under RCRA and has been assigned EPA Hazardous Waste No. U136. This substance has been banned from land disposal.

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 these substances.

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 arsenic, organic compounds 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 organic arsenic compounds. 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 organic arsenic compounds. There are no published reports on the resistance of various materials to permeation by organic arsenic compounds. However, readers are advised to inquire about information regarding protection against exposure from the specific organic arsenic compounds in use.

To evaluate the use of PPE materials with organic arsenic compounds, 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 arsenic, organic compounds.

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 136:1285-1296.

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

DOT [1993]. 1993 Emergency response guidebook, guide 53. Washington, DC: U.S. Department of Transportation, Office of Hazardous Materials Transportation, Research and Special Programs Administration.

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.

IARC [1980]. IARC monographs on the evaluation of carcinogenic risk of chemicals to man. Volume 23. Lyon, France: World Health Organization, International Agency for Research on Cancer.

IARC [1987]. IARC monographs on the evaluation of carcinogenic risk of chemicals to man. Supplement 7. Lyon, France: World Health Organization, International Agency for Research on Cancer.

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

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

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

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

NIOSH [1995]. Registry of toxic effects of chemical substances: Arsanilic acid. 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 [1995]. Registry of toxic effects of chemical substances: Cacodylic acid. 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: Arsenic. Trenton, NJ: New Jersey Department of Health.

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

NLM [1995]. Hazardous substances data bank: Cacodylic acid. 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.

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

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

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