Tobacco Documents Online

FOLto LESLIE W. MICHAEL 6. "Documentation of the Threshold Limit Values of Substances in Workroom Air," ACGIH. Third ed., Cincinnati. Ohio, 197 1. . 7. "Federal Mine Safety and Health Act of 1977," Public Law 95-16d, signed Yovember 9. 1977. 8. Goldsmith, J. R., and Aronow, W. S. Carbon monoxide and coronary heart disease: A review. Enriron. Res. 10, 236-248 (1975). 9. Hurchison, 6t K., Ed. "A Guide to-the Work-Relatedness of Disease." U-S- Dept. of HEW. PHS. Center for Disease Control, NIOSH, DHEW 77-123. 1976. 10. Lynch. 1. J., and Burgess, W. A. A personal exposure sampler for carbon monoxide. Amer. 1nd. H7g. Ass. 1. 35. 354-358 (1974). 11. "Occupational Exposure to Carbon Monoxide: Criteria for a Recommendcd Standard." U.S. Dept. of HEW, Health Services and Mental Health Admin., NIOSH. HSM 73-11000, 1971. 12. "Occupational Safety & Health Act of 1970." Public Law 91-596, si¢ncd December 29. 1970, 13. Parker, C. D., and Strong„R. B. "Evaluation of Portable Direct-Reading Carbon Uono.ida Meters." U.S. Dept. of HE W, PHS, Center for Disease Control. NIOSH. DH E W 75- 100. 1974. 14. Scott. W. D., James, R. H., and Bates, C. E.-Foundg• air contaminants from green sand molds. -`~---~ r--~ - i- ~- <-- --~ i Amer. Jnd. Hvg. Asmc. J. 37..fJJ-344 (1976). 1S. "Threshold Limit Valucs for Airgomc Con(aminants," ACGIH, Cincinnati. Ciaaier.at>. Ohfo. 1968. / ~ 16. "Threshold Limit Values for Chemical Substances in Workroom Air," ACGIH. Cincinoati. Ohio, 1977. 17. "Toxic Substances." in'_9 CFR i910.1029 and Fed. Reg. 4i, No. 206, Ocr. 22. 1976. 18. "Toxic Substances," in 29 CFR 1910.1000 and Fed. Reg. 36. No. 105. May 29. 1971. - 19. Virtamo. M., and Tossavamin. A. Carbon monoxide in foundry air. Srand. J. 3,4 Em'i.nn. Health 2. Suppl. I. 37-41 (1976). - - oN ri3F-

LESLIE W. MICHAEL TABLE I Joe TITLES wITH POTENTIAL CARBON \[OFOXIDE ExPOSCFE (9. 11) Acetic acid makers Airplane pilots Airport workers Ammonia maken Arc weldeits Artificial abrasive makers Artificial garworkers Automobile users Bakers Bisque-kiln workers Blacksmiths Blast furnace gas users Blast furnace workers Blockers (felt hat) Boiler room workers _ Brass founders Brewers Brick burnen - Bus driven Cable splicers Carbide makers Carbon monoxide workers Cement makers Charcoal burners i.(, ChauRen Chimney masons Chimney sweepers Cual dislillers \ Coke oven workers Compressed-air workcrs Cupola workers Diesel engine operators Divers Dock workers Drier workers - - Fireman Enamelers Fisch<r-Tropsch process workers - Formaldehyde makers ' Foundry workers Furnace starters Garage mechanics Gas workers (illuminating) Gasoline engine testers Gas station attendants Heat treaters Iron workers Kraft recovery furnace workers Laundry workers Lift truck operators (Propane and gasolinel Lime kiln workcrs Mercury smeltcrs Metal oxide reducers Metal refiners Methanol makers - Miners Mond process workers - Monosypcrs Nickel refiners ~ Nickel smelters Organic chemical sy'mhesizers Oaalic acid makers Parking anendams- Patentlealher makers - Police Producer gas workers Pottery-kiln workers Refinery workers Sanitation workers Steel makers Sewtr workers Stokers Solderers Taxi dricers Toll colleclors IHighway) Traffic controllers Tunnel attendants - . Tunnel workers Warehouse workers Water gas workers Welders - Wood distillers - - Zinc white makers The standards regulating health hazards in the workplace are promulgated by similar processes for each of the two enforcement agencies. The current standards have come through adoption of consensus standards or federal standards existing at the time of promulgation. The source of these health standards has been the American Conference of Governmental Industrial Hygienists (ACGIH) and the American National Standard<_ Institute (ANSI) formerly the American Standards Association. The respective learned committees of these organizations, the .oNri3'nr

WORKSHOP: CARBON MONOXIDE AND CVD -.• f Threshold-Limit Value Committee (TLV) and the Z37 Committee, respectively, prepare documentation in-support of the standards proposed by organizations. A compilation of the terms frequently encountered in exposure-limit descriptions are shown in Table 2. The term, Permissible Exposure Limit, (PEL) has been adopted as the description of enforcement standards to distinguish it from the consensus recommendations. The standard forcarbon monoxide enforced by both OSHA and MSHA is as follows: An employee's exposure to carbon monoxide in any light-hour work shift of a 40-hr workweek, shall not exceed an 8-hr time-weighted average of 50 ppm or 55 mg/m' (l8). - A review of the origin of the carbon monoxide PEL is appropriate. The basic information for the standard is cited in "Documentation of the Threshold-Limit Values" (6). The current 50-ppm time-weighted average (TWA) level was first proposed in 1965. Prior to that period,-the recommended TLV had been 100 ppm. In keeping with the requirement of the ACGIH that proposed changes appear in the annual recommendations for a 2-year period in order to receive comments. != " -- i TABLE2 TERMS USED TO DESCRI9E OCCUPATIONAL EXPOSL'RE LIMITS MAC Maximum Acceptable Concentration. The American National Standards distinguishes three different MAC's.° MAGTWA Maximum Acceptable Concentration Time-Wcighted Average is the time- weighted average eoncentration for protection of health assuming an 8-hr workday. Concentrations are restricted to be within the MAC-peak and MACaeiling concentrations described below. MAC-peak Maximum Acceptable Concentration for Peaks is Ihe highest concentration acceptable within a given time interval during an ghr workday- (Formerly Maximum Allowable Concentration.) MAC-ceiling Maximum Acceptable Conccntration for ceiling is the highest concentra- tion acceptable if the time-weighted average is within the MAC-TWA value. PEL Permissible Exposure Limit- An employee's exposure to any material." the name of which is not preceded by "C',s in any &hr work shift of a 40-hr workweek shall not exceed the 8-hr time-weighted average given for that material. C CEILING. An employce's exposure to any material.°' the name of which is preceded by a "C", shall at no time exceed the value given for that material. Acceptable ceiling concentrations as described in MAC-ceiling except for a time period and up to a concentration not exceeding the MAC- peak (18). TLV Threshold-Limit Valucs refer to time-weighted concentrations for a 7- or 8-hr workday and 40-hr workweek. (15). . STEL Short-Term Exposure Limit. Refers to the maximal concentration to which workers can be exposed in a I5-min period (16). ' American National Standards Institute. Inc., 1430 Broadway. New York. New York 10018 s'-C- refers to ceiling as described after PEL or in (18). Different ceilin¢ Icrms apply depending 111 on which materials are cited. ' Material refers to the substances in Tables of Standards as shown in (18) .

Compliance with the Carbon Monoxide Standard in the Workplace' LESLIE W. j<tICHAEL ' Occupalional Safery and Health Ad/ninisrrnlian, 14/kJ 7nnence Ar'rmrc, Culuurent Cirr. /llin,. is 60409 Received October 20. 1978 - The carbon monueide standard which the Department of labor uses for the proteclion of workers' health is reviewed. The legistation, origin of Ihe stanJard, and enforcement in the workplace are summarized. The agencies within the Department of Labor with enforcement responsibilities arc the Occupalional Safetv and Heahh Administration fOSHAI and the Mine Safety and Health Administration (61SHA). Comparisons are made with (he current federal standard of 50 ppm and other existing or proposed slandards. An increasing aware- ness of the effects of carbon monoxide suggests changes in the standard. A standard based on carboxy-hemoglobin levels of exposed nonsmokers that overlaps the levels of normal smokers raises difficult questions. The imponanec of mainlenance and monitoringas well as controls in the management of potential carbon monoxide exposure in the worAp7ace is - stressed. Carbon monoxide (CO) ranks second to carbon dioxide in total annual emis- sions. Approximately 607c of the annual emissions result from hydrocarbon- powered internal combustion engines and 10% from industrial sources. About 2000 persons-succumb annually as a-direct result of CO exposure 11, 2). The potential for exposure at the workplace is apparent from the variety of occupations associated either directly or indirectly with the gas.-A partial list of job titles is shown in Table 1. These do not include more complete delineation of some titles. Coke-oven workers for example, have a number ofjob classifications which include: lidman, tar chaser, larry-car operator, luterman, machine operator coke side, benchman coke side, benchman pusher side, heater, quenching-car operator, pusher-machine operator, screening-station operator, wharfman, oven _ patcher, oven repairman, spellman, and maintenance personnel (9, 10. The Secretary of Labor, through his enforcement agencies, regulates exposure in the more than 80 job classifications with the potential for exposure to CO. The two regulatory agencies with statutory power are the Occupational Safety and Health Adminis-tration (OSHA) and the Mine Safety and Health Administration (hfSHA). OSHA was formed by the Occupational Safety and Health Act of 1970. MSHA was formed within the Department of Labor by the Federal Mine Safety and Health Act of 1977. PPreviously, the Mine Enforcement and Safety Adminis- tration, within the Department of the Interior, had the responsibilities assumed by hiSHA on March 9. 1978 (7, 12). ~ - . - --- - ~ ' Presented at a workshop on Carbon Monoxide and Cardiovascutar Disease, sponsored by the American Hcahh Foundation and the Federal Health Office, Federal Republic of Germany, Berlin. October 10-12. 1978. - 0091-7435/79;0083-0000so7 0110 . - conrrani p wn bs 11,11, n.... In/ All nrMinf /tOMlwliw m.eY rrnm re.rnN. 2 3 `979

LESLIE W. MICHAEL The current level was officially adopted in 1967. Opportunity for review was a requisite for adoption as an enforcement standard. The chronology is pertinent as it explains how the 1968 ACGIH-TLV's are now federal standards for OSHA and the 1973 values are federal standards for SiSHA. 05HA did not incorporate any of the proposed changes in the current list of ACGIH-TLV's at the time of adop- lion, 1970 (18). Therefore, the 1968 values represented the current consensus standards of the ACGIH at that time. This is the same view held by ANSI as indicated by their MAC-ceiling at that time. This is also the standard used in some other countries, although, as shown in Table 3, it is not recommended universally as an exposure limit. In summary, the current federal standards represent the consensus of a nationally recognized body in the late 1960's. The key phrase in the development of the current standard is as follows: "The recommended TLV for CO of 50 ppm is based on an air concentration that should not result in blood CO levels above i09'c, a level that is just below the development of signs of borderline effects." The symptoms cited earlier in the document in- clude headache, fatigue, and dizziness at 107o carboxyhemoglobin (HbCO) levels. Disturbance of coordination, judgment, psychomotor tasks, and visual acuity ap- pear at 2% HbCO and become important at 5% HbCO. Discrimination errors and reaction times increase and the threshold of light sensitivity of the eye decreases at about the 5% HbCO saturation. Each of these factors was also cited (6). Varia- tions in individual susceptibility and of prior or existing conditions alter the re- sponse to given levels of CO. Combined exposure to other occupational health hazards, therapeutic drugs, or other toxic agents bear on the individual response, ~- ~ were noted in the documentation (6), and have subsequently been elaborated upon (8). Change in PEL is complicated by two population groups in the working envi- ronment, smokers and nonsmokers. SmokeYs have COHb hemoglobin levels of 2 to 10% (6). Since these levels embrace the values currently being addressed as the basis for the occupational exposure limit, the level of protection provided by a given standard may not offer the same protection to these two different groups. These factors are noted by both NIOSH and ACGIH and are of increasing con- _ cem (6, 8, 11). Enforcement monitoring of carbon monoxide levels in the work- place must be consistent with the standard. Monitoring must, therefore, be rep- - resentative of the time-weighted average exposure of the worker. This requires a small number of spot checks or continuous personal monitoring. Gas detector tubes are available from a number of manufacturers. Testing and approval of these devices are conducted by NIOSH. Construction and performance requirement for TABLE 3 STANDARDS OR RECON.1SENDATIONS FOR OCCUPATIOVAL ECPOSURE TO CARBON VO1OSIDE (I I, 16) 15 ppm 18 ppm 25 ppm 35 ppm 50 ppm 200 ppm 400 ppm ~T--- _ _ _ _ _ - _ opy ri9 nr National Aeronautics and Space Administration Maximum Allowable Concentration U.S.S.R. ACGIH at allitudes of 1500 to 2500 m N1OSH Permissible-Exposure Limit USA and West Germany NIOSH ceiling ACGtH Short-Term Exposure Limit. I I (,J .'Ti

t t WORKSHOP: CARBON DIONOXIDE AND (VD •_ the color changes and length of stain devices require an accuracy of '_25 c at one, two and five times the test standard of the contaminant of interest. In addition, a tolerance of t33% of the actual value at one-half the test standard is required (5). It should be note that MSHA monitoring techniques are restricted to devices with approval in mine atmospheres. Approval programs for continuous direct-reading devices are not currently available. An evaluation of portable direct-reading CO meters has been prepared (13). Reports of CO levels and/or HbCO levels in the NIOSH document predate 1972 - (1I). The review of the literature of that period indicated CO exposure to workers in automobile repair shops, to parking attendants, to dockworkers, to inspectors at border stations, to tunnel workers, and to steel mill w'orkers was in excess of _ the federal standard. - - Reports in the current literature show.similar results for toll both attendants (2) and fire fighters (3). High concentrations were also observed in foundries (14, 19) and tunnels (10). - __ Control strategies for occupational exposure to CO suegest a need for a major emphasis on maintenance activities. The large number of gas-powered engines associated with CO emissions and the state of repair of the engines bear on occupational exposure. Effective control is compromised by third-party concern in some case. For example, CO emissions into a warehouse by vehicles not maintained by the warehouse owner might be a source of exposure to warehouse employees. In facilities where CO emissions are process related. ventilation must be de- signed to accommodate the largest levels of emissions anticipated. Continuous maintenance and appropriate monitoring is essential to the ability of the equip- ment to continue to meet design specifications. Management needs to be con- cerned continuously with changes in their facilities which might compromise con- troltechnologies.` - - As knowledge increases both with respect to health effects and engineering designs related to processes and controls, careful attention should be given to high-level exposures of short duration. An-increasing body of literature would suggest that such exposures, which are not adequately addressed by the current federal standard, may be deleterious to the health of employees (8). t --- - REFERENCES - 1. "Air Quality Criteria for Carbon Uonoaide." U.S. Dept. of HEW. NAPCA Pub. No. AP-6'-, Washington, D.C.. 1970. 2._ Burgess. W. A., Dieberardines, L.. and Speizer, F. E. Hcatth effects of exposure to automobile - exhaust-V,exposureoftollboolhoperatorstoautomobileexhamt-drnecLrd.lAp..iss.J.38, -- 184-191 (I977). 3. Burgess, W. A.. Sivor, R., Lynch. J. 1., Buchanan, P.. and Cloueherty. E. Minimum protective factors for respiratory protection devices fer firefighters. Amer. rnd. /f,g. Ass. J. 38. 18-23 ([977). 4. "Carbon t.lonozide," U.S. Dept. of Labor. Occupational Safety and Health Adminiaration, p. 3. 2214 1975 5. Certification of Gas Detectur Tubes. 42 CPR 84, Subpan G, in "N'IOSH Cernifed E.quipment:' U.S. Department of HEW, PHS, Center for Disease Control. NIOSH. HE W 76145. 1975. scll/" atso "Cumulative Supplement," DHEW 77-195. 1977.