Document zowamkaNaEqMg2mZVrkXzXv2B

Dovid n. Kuhn To Plant Safety Directors For your information. DAK/ac att. (conoco) Date 12/16/75 SAL Recommended Standard nrcEivfP EC r-lb/t- for Occupational Exposure To Xylene complete criteria document for occupational exposure to xylene has in prepared by the National Institute for .Occupational Safety and Health (NIOSH). NIOSH recommends adherence to the present Federal Standard of 100 ppm as a time-weighted average for up to a 10-hour workday, 40-hour workweek. NIOSH also recommends a ceiling concentration of 200 ppm as determined by a sampling period of 10 minutes. The recommended standard is part of a continuing series of criteria documents developed by NIOSH in accordance with the Occupational Safety and Health Act of 1970. The document was transmitted to the Occupational Safety and Health Administration in the Department of Labor on May 23, 1975, for review and consideration in the standard setting process. Xylene, also called dimethylbenzene or xylol, is produced commercially from both petroleum and coal tar. Total United States xylene production in 1971 was 612,325,000 gallons, and NIOSH estimates that 140,000 workers are potentially exposed. Xylene is an organic solvent for some gums, resins, and oils and is a constituent of paint, lacquers, varnishes, inks, dyes, ad hesives, and cleaning fluids. It is also an additive in gasoline. The proposed standard would apply to the processing, manufacture, use, or other occupa tional exposure to xylene as applicable under the Occupational Safety and Health Act of 1970. Xylene has an irritant effect on the skin and mucous membranes and can have variable effects on the liver, kidneys, and gastrointestinal tract. Another major problem of xylene toxicity is its narcotic effect on workers, causing symptoms such as muscular weakness, lack of coordination, and mental confusion which may pose a risk to the worker and others. Current evidence indicates that xylene is not toxic to the blood and blood-forming organs. NIOSH recommends comprehensive preplacement medical examinations, with subsequent examinations every 2 years, for workers subject to xylene exposure. It is also recommended that containers of xylene have labels warning of flammability and that personal protective equipment be provided to prevent skin or eye contact. The NIOSH document calls for engineering controls to be used wherever feasible to maintain xylene concentrations below the prescribed limits with respirators used only in certain nonroutine or emergency situations. The criteria document was reviewed by five consultants, two professional societies, and by Government agencies having interest and responsibility for occupational safety and health. The proposed standard is considered appro priate and no additional information that would affect the recommended standard is now available. The following is the first chapter of the criteria document. It contains the NIOSH recommendations for controlling worker exposure to xylene. U.S. DEPARTMENT OF HEALTH, EDUCATION, AND WELFARE Public Health Service Center for Disease Control National Institute for Occupational Safety and Health Single copies of complete criteria document are available from: Office of Technical Publications National Institute for Occupational Safety and Health Post Office Building Cincinnati, Ohio 45202 Please Include a self-addressed mail ing label to assist In answering your request. R commended Standard I. RECOMMENDATIONS FOR A XYLENE STANDARD The National Institute for Occupational Safety and Health (NIOSH) recommends that employee exposure to xylene in the workplace be controlled by adherence to the following sections. The standard is designed to protect the health and safety of workers over a working lifetime; compliance with all sections of the standard should therefore prevent adverse effects of xylene on the health and safety of workers. The standard is measurable by techniques that are valid, reproducible, and available to industry and government agencies. Sufficient technology exists to permit compliance with the recommended standard. The criteria and standard will be subject to review and revision as necessary. Regardless of the source of raw materials from which produced, "xylene" (also known as "xylol" or "dimethylbenzene") refers to any one of or combination of the isomers of xylene: ortho-, meta-, or para-dimethylbenzene. The term "xylene" will be used throughout this document. "Exposure to xylene" is defined as exposure above half the recommended timeweighted average environmental limit. If "exposure" to other chemicals also occurs, for example from con tamination of xylene with benzene, provisions of any applicable standard for the other chemicals shall also be followed. Section 1 -- Environmental (Workplace Air) (a) Concentration Occupational exposure to xylene shall be controlled so that workers are not exposed to xylene at a concen tration greater than 100 parts per million parts of air by volume (approximately 434 milligrams per cubic meter of air) determined as a time-weighted average (TWA) exposure for up to a 10-hour workday, 40-hour workweek, with a ceiling concentration of 200 parts per million parts of air by volume (approximately 868 milli grams per cubic meter of air) as determined by a sampling period of 10 minutes. (b) Sampling, Collection, and Analysis Procedures for collection and analysis of environ mental samples shall be as provided in Appendices I and II or by any other method shown to be equivalent in accuracy, precision, and sensitivity to the method specified. Section 2 -- Medical Comprehensive preplacement and biennial (every 2 years) medical examinations should be provided for all workers subject to "exposure to xylene." The history and examination should be directed toward, but not limited to, the incidence of headaches, nausea or other gastrointestinal disturbance, dizziness, and of alcohol consumption. Particular attention should be focused on complaints and evidence of eye, mucous membrane, or skin irritation. Laboratory tests recommended at the time of the biennial examination include a complete blood count, a routine urinalysis, and appropriate liver function tests. Section 3 -- Labeling (Posting) (a) Labeling Containers of xylene shall carry a label stating: XYLENE (XYLOL, DIMETHYLBENZENE) WARNING! FLAMMABLE HARMFUL IF INHALED OR SWALLOWED IRRITATING TO SKIN OR EYES Keep away from heat, sparks, and open flame. . In case of fire, use foam, dry chemical, or C02. Avoid breathing vapor. Avoid contact with eyes, skin, and clothing. Keep container closed. Use with adequate ventilation. Do not use for washing hands, floors, or equipment. First Aid: In case of eye or skin contact with liquid xylene, wash with plenty of water. If eye contact, call a physician. If swallowed, call a physician. Do not attempt to induce vomiting, (b) Posting Areas where there is occupational exposure to xylene shall be posted with a sign reading: XYLENE WARNING! FLAMMABLE HARMFUL IF INHALED OR SWALLOWED IRRITATING TO SKIN OR EYES Keep out heat, sparks, or open flames. No smoking permitted. In case of fire, use fire extinguishers. (Give location) Avoid breathing vapor. Avoid contact with skin, eyes, and clothing. Provide adequate ventilation. This warning sign shall be printed both in English and in the predominant language of non-English-speak ing workers, unless they are otherwise trained and informed of the hazardous areas. All illiterate workers shall receive such training. Section 4 -- Personal Protective Equipment (a) Protective Clothing (1) Chemical safety goggles, face shields, or safety glasses with side shields shall be provided by the employer and shall be worn in any operation in which xylene may splash into the eyes. (2) Appropriate protective clothing, including gloves, aprons, suits, boots, or face shields, shall be worn where needed to prevent repeated or prolonged skin contact. NID5H Recomm nded Standard ITT (b) Respiratory Protection (1) Engineering controls shall be used wherever feasible to maintain xylene concentrations below the prescribed limits. Such control equipment shall be sparkproof. Compliance with the permissible exposure limit may not be achieved by the use of respirators except: (A) During the time period necessary to in stall or test the required engineering controls. (B) For nonroutine operations such as a brief exposure to concentrations in excess of the per missible exposure limit as a result of maintenance or repair activities. (C) During emergencies when air concen trations of xylene may exceed the permissible limit. (2) When a respirator is permitted by paragraph (b) (1) of this Section, it shall be selected and used pursuant to the following requirements: (A) For the purpose of determining the type of respirator to be used, the employer shall measure, when possible, the atmospheric concentration of xylene in the workplace initially and thereafter whenever process, worksite, climate, or control changes occur which are likely to increase the xylene concentrations; this requirement shall not apply when only atmos phere-supplying positive pressure respirators will be used. The employer shall ensure that no worker is being exposed to xylene in excess of the standard because of improper respirator selection, fit, use, or maintenance. (B) A respiratory protection program meet ing the requirements of 29 CFR 1910.134 as amended shall be established and enforced by the employer. (C) The employer shall provide respirators in accordance with Table 1--1 below and shall ensure that the employee uses the respirator provided. (D) Respiratory protective devices described in Table 1--1 shall be those approved under the pro visions of 30 CFR 11 as amended. (E) Respirators specified for use in higher concentrations of xylene may be used in atmospheres of lower concentrations. (F) The employer shall ensure that respira tors are adequately cleaned, and that employees are instructed on the use of respirators assigned to them, and on how to test for leakage. (G) Where an emergency may develop which could result in employee injury from overexposure to xylene, the employer shall provide respiratory protec tion as listed in Table 1--1. Section 5 -- Informing Employees of Hazards from Xylene (a) Each employee exposed to xylene shall be in formed at the beginning of his employment or assignment to a xylene area of the hazards, relevant symptoms, appropriate emergency procedures, and proper conditions and precautions for safe use or exposure. Each employee shall be instructed as to the availability of such information which shall be kept on file. Information kept on file shall include that prescribed in (b) below and shall be accessible to the worker at each place of employment where xylene is involved in unit processes and operations. (b) Information as specified in Appendix III shall be recorded on US Department of Labor Form OSHA20, "Material Safety Data Sheet," or on a similar form approved by the Occupational Safety and Health Ad ministration, US Department of Labor. Section 6 -- Work Practices (a) Emergency Procedures For all work areas in which there is a reasonable potential for emergencies, procedures as specified below, as well as any other procedures appropriate for a specific operation or process, shall be formulated in advance and employees shall be instructed in their implementation, (1) Procedures shall include prearranged plans for obtaining emergency medical care and for necessary transportation of injured workers. (2) Firefighting procedures shall be established and implemented. These shall include procedures for emergencies involving release of xylene vapor. In case of fire, xylene sources shall be shut off or removed. Containers shall be removed or cooled with water spray. Chemical foam, carbon dioxide, or dry chemicals should be used for fighting xylene fires, and proper respiratory protection and protective clothing shall be worn. (3) Approved eye, skin, and respiratory protec tion as specified in Section 4 shall be used by per sonnel essential to emergency operations. (4) Nonessential employees shall be evacuated from exposure areas during emergencies. Perimeters of areas of hazardous exposures shall be delineated, posted, and secured. (5) Personnel properly trained in the procedures and adequately protected against the attendant hazards shall shut off sources of xylene, clean up spills, and immediately repair leaks. (b) Engineering controls such as process enclosure or local exhaust ventilation shall be used to maintain xylene concentrations within the recommended environ mental limits. All such control equipment shall be sparkproof. Ventilation systems shall be designed to prevent the accumulation or recirculation of xylene in the workplace and to effectively remove xylene from the breathing zones of exposed workmen. Exhaust ventilation systems discharging to outside air must conform with applicable local, state, and federal air pollution regulations. Ventilation systems shall be sub ject to regular preventive maintenance and cleaning to ensure maximum effectiveness, which shall be verified by periodic airflow measurements. (c) Containers of xylene shall be kept tightly closed at all times when not in use. Containers shall be stored in accordance with the provisions of 29 CFR 1910, and shall be protected from heat, corrosion, mechanical damage, and sources of ignition. (d) Washing of hands, equipment, or structures with 'xylene shall be prohibited. (e) Any spills of xylene shall be promptly cleaned up. (f) Prior to maintenance work, sources of xylene SAL. OOOO44'J 28 Recommended Standard TABLE 1--1 RESPIRATOR SELECTION GUIDE FOR PROTECTION AGAINST XYLENE Multiples of TWA Limit Less than lOx Less than 50x Less than lOOx lOOx or more CAUTION! The lower explosive limit is approximately 11,000 ppm Unknown concentration Escape Respirator Type Chemical cartridge respirator with full facepiece and organic vapor cartridge(s). Gas mask (full facepiece) with a chin-style organic vapor canister. (1) Gas mask (full facepiece) with front or back mounted organic vapor canister. (2) Type C supplied air respirator with a full facepiece oper ated in the demand (negative pressure) mode. (3) Type C supplied air respirator with a full facepiece oper ated in the pressure-demand (positive pressure) or con tinuous flow mode. (4) Self-contained breathing apparatus with a full facepiece operated in the demand (negative pressure) mode. (5) Combination Type C supplied air respirator with full facepiece operated in the demand (negative pressure) or continuous flow mode and an auxiliary self-contained air supply operated in the demand (negative pressure) mode. (1) Self-contained breathing apparatus with a full facepiece operated in the pressure-demand (positive pressure) mode. (2) Combination Type C supplied air respirator with full facepiece operated in the pressure-demand (positive pressure) or continuous flow mode and an auxiliary self-contained air supply operated in the pressure-de mand (positive pressure) mode. Self-contained breathing apparatus with a full facepiece operated in the pressure-demand (positive pressure) mode. (1) Gas mask (full facepiece) with chin style or front or back mounted organic vapor canister. (2) Self-contained breathing apparatus with full facepiece operating either in the demand (negative pressure) or pressure demand (positive pressure) mode. and xylene vapor shall be eliminated to the extent feasible. If concentrations below the workplace air limit cannot be assured, respiratory protective equip ment shall be used during such maintenance work. (g) All metal dispensing containers shall be prop erly grounded. Section 7 -- Sanitation (a) Food Facilities Food preparation, dispensing (including vending machines), and eating should be prohibited in xylene work areas. (b) Smoking Smoking shall not be permitted in areas where xylene is used, transferred, stored, or manufactured. Section 8 -- Monitoring and Recordkeeping Workroom areas shall not be considered to have xylene exposure if environmental levels, as determined on the basis of a professional industrial hygiene survey Sft'- 0 000 A A Recommended Standard or by the judgment of the compliance officer, do not exceed half of the recommended time-weighted average limit. Records of these surveys, including the basis for concluding that air levels are at or below half of the time-weighted average limit, shall be maintained until a new survey is conducted. Surveys shall be repeated when any process change indicates a need for reevalu ation or at the judgment of the compliance officer. Requirements set forth below apply to areas in which there is xylene exposure. Employers shall maintain records of environmental exposures to xylene based upon the following sampling and recording schedules: (a) In all monitoring, samples representative of the exposure in the breathing zone of employees shall be collected. An adequate number of samples shall be collected to permit construction of a time-weighted average (TWA) exposure for every operation or process. The minimum number of representative TWA deter minations for an operation or process shall be based on the number of workers exposed as provided in Table 1--2. (b) The first environmental samples shall be com pleted within 6 months of the promulgation of a stan dard incorporating these recommendations. (c) Environmental samples shall be taken within 30 days after installation of a new process or process change. (d) Samples shall be collected at least quarterly in accordance with Appendix I for the evaluation of the work environment with respect to the recommended standard. (e) Environmental monitoring of an operation or process shall be repeated at 30-day intervals when the xylene concentration has been found to exceed the recommended environmental standard. In such cases, suitable controls shall be initiated and monitoring shall continue at 30-day intervals until two consecutive surveys indicate the adequacy of these controls. (f) Sampling records shall be maintained so that exposure information is available for individual em ployees and shall indicate the type of personal pro tective devices, if any, in use at the time of sampling. Each employee shall be able to obtain information on his own environmental exposure. TABLE 1--2 SAMPLING SCHEDULE Number of Employees Exposed 1-20 21-100 over 100 Number of TWA Determinations 50% of the total number of workers 10 plus 25% of the excess over 20 workers 30 plus 5% of the excess over 100 workers V OUSGPO: 1975 -- 657-645/209