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This guideline summarizes pertinent information about western red cedar dust 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 Recommendations may be superseded by new developments in these fields; readers are therefore advised to regard these recommendations as general guidelines and to determine whether new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.
Not applicable* Structure
(For Structure, see paper copy)* Synonyms
Finely divided wood particles, powdered wood, sawdust, wood flour, softwood dust, wood dust* Identifiers
1. CAS No.: Data not available* Appearance and odor
Western red cedar dust is any wood particle arising from the processing or handling of western red cedar. This wood has a very characteristic cedar smell.CHEMICAL AND PHYSICAL PROPERTIES
* Physical data
1. Molecular weight: Not applicable.* Reactivity
1. Conditions contributing to instability: None reported.* Flammability
The National Fire Protection Association has not assigned a flammability rating to western red cedar dust. Other sources rate western red cedar dust as a combustible solid when this substance is exposed to heat or open flame.EXPOSURE LIMITS
* OSHA PEL
The Occupational Safety and Health Administration (OSHA) has established a permissible exposure limit (PEL) of 15 milligrams per cubic meter (mg/m(3)) for the total dust and 5 mg/m(3) for the respirable fraction of western red cedar dust (as a nuisance dust).* NIOSH REL
The National Institute for Occupational Safety and Health (NIOSH) has established a recommended exposure limit (REL) for western red cedar dust of 1 mg/m(3) of air, as a TWA for up to a 10-hour workday and a 40-hour workweek [NIOSH 1992].* ACGIH TLV
The American Conference of Governmental Industrial Hygienists (ACGIH) has assigned western red cedar dust (as a soft wood) a threshold limit value (TLV) of 5 mg/m(3) as a TWA for a normal 8-hour workday and a 40-hour workweek and a short-term exposure limit (STEL) of 10 mg/m(3) for periods not to exceed 15 minutes. Exposures at the STEL concentration should not be repeated more than four times a day and should be separated by intervals of at least 60 minutes [ACGIH 1994, p. 36].* Rationale for Limits
The NIOSH limit is based on the risk of pulmonary dysfunction and other respiratory effects [NIOSH 1992].
HEALTH HAZARD INFORMATION
* Routes of Exposure
Exposure to western red cedar dust can occur through inhalation, ingestion, and eye or skin contact.* Summary of toxicology
1. Effects on Animals: No information was available on the health effects of western red cedar dust on experimental animals.* Signs and symptoms of exposure
1. Acute exposure: Acute exposure to western red cedar dust may result in irritation of the eyes, skin, or respiratory tract.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 western red cedar dust and lead to worker exposures to this substance:
Good sources of information about control methods are as follows:
1. ACGIH . Industrial ventilation--a manual of recommended practice. 21st ed. Cincinnati, OH: American Conference of Governmental Industrial Hygienists.
2. Burton DJ . Industrial ventilation--a self study companion. Cincinnati, OH: American Conference of Governmental Industrial Hygienists.
3. Alden JL, Kane JM . Design of industrial ventilation systems. New York, NY: Industrial Press, Inc.
4. Wadden RA, Scheff PA . Engineering design for control of workplace hazards. New York, NY: McGraw-Hill.
5. Plog BA . Fundamentals of industrial hygiene. Chicago, IL: National Safety Council.
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 western red cedar dust 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 western red cedar dust, 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 respiratory system [NIOSH 1994a]. Medical surveillance for respiratory disease should be conducted using the principles and methods recommended by the American Thoracic Society.* 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 western red cedar dust exposure. The interviews, examinations, and medical screening tests should focus on identifying the adverse effects of western red cedar dust on the skin or respiratory system [NIOSH 1994a]. 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 western red cedar dust.WORKPLACE MONITORING AND MEASUREMENT
Determination of a worker's exposure to airborne western red cedar dust is made using a tared low ash polyvinyl chloride filter (5 microns) preceded for respirable fraction sampling by a 10 mm nylon cyclone. Samples are collected at a maximum flow rate of 1.7 liters/minute (respirable fraction) or 2.0 liters/minute (total dust) until a maximum collection volume of 816 liters (respirable fraction) or 960 liters (total dust) is reached. Analysis is conducted by gravimetric methods. This method (for nuisance dusts) is described in the OSHA Computerized Information System [OSHA 1994] and is fully validated. NIOSH has published a similar method (Method No. 0500) for the sampling and analysis of nuisance dusts [NIOSH 1994b].
PERSONAL HYGIENE PROCEDURES
If western red cedar dust contacts the skin, workers should flush the affected areas with plenty of water, followed by washing with soap and water.
Clothing contaminated with western red cedar dust should be removed when convenient, and provisions should be made for the safe removal of the dust from the clothing. Persons laundering the clothes should be informed of the hazardous properties of western red cedar dust.
A worker who handles western red cedar dust 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 western red cedar dust is generated.
Western red cedar dust 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 western red cedar dust should be protected from physical damage and should be stored separately from all sources of ignition.
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
Western red cedar dust 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].* 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 western red cedar dust 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 western red cedar dust 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.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 western red cedar dust 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 western red cedar dust. 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 western red cedar dust.
To evaluate the use of PPE materials with western red cedar dust, 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 western red cedar dust.
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.
ACGIH . Documentation of the threshold limit values and biological exposure indices. 6th ed. Cincinnati, OH: American Conference of Governmental Industrial Hygienists.
ACGIH . 1994-1995 Threshold limit values for chemical substances and physical agents and biological exposure indices. Cincinnati, OH: American Conference of Governmental Industrial Hygienists.
ATS . 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.
Genium . Material safety data sheet No. 376. Schenectady, NY: Genium Publishing Corporation.
Lewis RJ, ed. . Hawley's condensed chemical dictionary. 12th ed. New York, NY: Van Nostrand Reinhold Company.
Mickelsen RL, Hall RC . 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 . 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 . Registry of toxic effects of chemical substances: Western red cedar dust. 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 . 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 [1994a]. 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.
NIOSH [1994b]. 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.
OSHA . Computerized information system. Washington, DC: U.S. Department of Labor, Occupational Safety and Health Administration.
USC. United States code. Washington, DC: U.S. Government Printing Office.