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Occupational Health Priorities for Health Standards: The Current NIOSH Approach Jimmy L Perkins, MS. and Vernon E Rose, DrPH Abstract: Government agencies responsible for protecting the public from the adverse effects of toxic chemicals must set priorities for research, regulatory action, protocol testing, and monitoring due to the vast number of toxic chemicals and the limited resources available to these agencies The National Institute for Occupational Safety and Health (NIOSH) must set pri orities for research on hazards encountered m the workplace Priorities are also utilized by NIOSH m preparing criteria for recommended occupational stan dards which are forwarded to the Occupational Safety and Health Administration (OSHA), U S Department of Labor, for possible promulgation For various rea sons, including rapidly changing conditions in the American workplace, NIOSH has instituted a revised priorities program In the future, NIOSH research and recommended standards activities will focus not only on individual chemicals, but also on industries, occu pations, chemical classes, and general industrial proc esses NIOSH has also implemented a new program which will allow recommended control procedures for certain chemicals to be forwarded to OSHA in a short er time period than has been experienced previously (Am J Public Health 69 444-449, 1979) Limits and constraints on budget and manpower are the major reasons for assessment of priorities Whether in gov ernment private enterprise, or academia, an orderly and sysiematic approach to the allocation of resources is neces sary For health-oriented government agencies, such as the National Institute for Occupational Safely and Healih (NIOSH). lhe Environmental Proiecnon Agency (EPA), the Food and Drug Administration (FDA), priorities for assess ing the possible health effects of toxic chemicals are a prima ry concern More than 9.000 chemicals were commercially produced in the Umied Slates in 1970 1 Currently the NIOSH Registry of Toxic Effects of Chemical Substances contains over 28.000 chemical entries * The Chemical Absiracung Service (CAS) has now registered more than 4,000.000 chemicals, and new CAS entries are being made at the rate of 21 000 per month 0 Clearly, these health agencies are faced with a monumental task tn developing priorities for research, protocol testing, monitoring, and regulatory ac tion Ideally, the assessment of each chemical should be based on several factors Toxicity, which may include pre- From lhe National Institute for Occupational Safety and Health, DHEW, Rockville, MD Address reprint requests to Jimmv L Perkins, MS. <418 Fairdale, Apl 65. Houston. TX 77057 This paper, submitted to the Journal June 30 1978, was revised and ac cepted for publicanon November 8, I97B dieted or documented adverse healih effects, and lhe popu lation at risk including the extent of that risk, are the most important factors Other factors with varying degrees of im portance include production levels, trends m use, environ mental conversion or fate, adequacy of previous research, testing, or standards setting attempts, and physical charac teristics such as volatility or physical state Unfortunately, the data needed to assess the priority of each chemical are not always available For example, production data are available for only a small percentage of chemicals due to the current proprietary nature of the information : Under provi sions of the 1976 Toxic Substances Control Act.1 production data should become available to certain agencies for the pur pose of establishing priorities for evaluation and regulation of chemical substances The two most important factors used in establishing pri orities, i e , toxicity and population at risk, are also the most difficult lo assess Methods used for assessing toxicity have varied considerably Stephenson* used the '`Delphi" meth od, a modified version of which was used by NIOSH as will be subsequent^ described In the Delphi approach,1 a panel of expens rank a senes of chemicals with or without the aid Unpublished data Registry ofTotic Effects of Chemical Sub stances, NIOSH Mav 1978 `Personnel commumcalion Chemical Abstract Service. PO Box 3012 Columbus OH 43210, March 24, 1978 444 AJPH May, 1979, Vol 69, No 5 RSV0033857 OCCUPATIONAL HEALTH PRIORITIES of supporting data The goal is to reach a consensus agree ment. or at least a narrowing of opinion, through an iterative process which allows each participant to see how his views fit with those of the group This method works best if the number of chemicals to be ranked is limited and well de fined For example. Stephenson ranked 80 chemicals, while NIOSH ranked 475 Brown* assessed the hazardousness of industries m Allegheny County. Pennsylvania, using report ed data indicating the incidence of occupational illness This method is simple and straightforward, however, occupation al illness data should not be relied upon as a sole factor, as the current adequacy and accuracy of illness reporting is poor and sometimes can be misleading.7 The population at risk factor includes level of exposure and duration or length of time of exposure. These variables are extremely difficult to assess. Early attempts to gam knowledge about chemical exposures in occupational popu lations' * did not include an assessment of airborne concen tration or time of exposure The 1974 NIOSH National Oc cupational Hazard Survey (NOHS)10 defined exposure time as either full-time or pan-time, pan-time designating four hours or less of exposure per day No attempt to assess con centration was made To simply state that 2,000,000 people are occupationally exposed to benzene does not address the complex issues of time and concentration Although these variables can be determined, the effon to do so for several thousand chemicals would be a time-consuming and costly task Consequently, simple population at risk estimates, such as those made using NOHS data, normally have to be used but their limitations should be understood Obviously, differences exist in the data that each federal agency uses for assessment of chemical priorities The EPA must consider environmental fate and the possibility of envi ronmental release NIOSH is concerned with occupational populations The FDA must consider therapeutic vs toxic effects of drugs Nevertheless, the major parameters eval uated by each agency for assessing chemical priorities usual ly include population at risk and toxicity, and each agency must concern itself with an enormous number of chemicals Development of the NIOSH Approach As required by the Occupational Safety and Health Act of 1970, NIOSH has attempted to remain cognizant of the large number of commercial chemicals to which varying numbers of workers are exposed Among other provisions, the Act directs NIOSH to develop and conduct research and experiments which will yield criteria for identifying toxic substances and for developing recommended occupational safety and health standards These recommended standards, or criteria documents, describe, among other items, safe ex posure levels and working conditions designed to ensure that "no employee will suffer impaired health or functional ca pacities or diminished life expeciancy as a result of the work experience ,|* Recommended standards are forwarded to the U S Department of Labor, Occupational Safety and Health Administration (OSHA). for promulgation and are al so available to employers, employees, and government agencies as guides for voluntary compliance AJPH May. 1879 Vol 69. No 5 NlOSH's commitment to setting priorities is based on the belief that such a systematic approach is necessary to ensure the effective utilization of limited resources, thereby having the greatest cost-effective impact on the health and safety problems facing the working population Priorities are established for the selection of subjects, for the preparation of cntena for recommended occupational standards, and for the conduct of laboratory' research These are not necessari ly independent, as much of the NIOSH research is related to providing necessary' information for effective preparation of cntena documents Currently NIOSH prepares 20 to 24 cri teria documents per year The subjects may include individ ual chemical or chemical or physical agents, classes or groups of agents, industries, occupations, or specific proc esses within an industry (see Appendices Tables 1 and 2) From 1972 until 1975, NIOSH compiled three priority lists Whiie different variables were utilized m compiling each list, population at risk and toxicity of the agent were used as a minimum in all three lists The 1972 pnonty list11 contained 19 sets of substances each set consisting of five or six subjects having equal pnonty Listed were individual toxic agents, including chemicals, mineral dusis. and phys ical agents The 1972 pnonty list w as based on a system developed by the staff of the former Bureau of Occupational Safety and Health, which became NIOSH in 1971 Subjective rankings were made by Bureau staff and field mdustnal hygienists us ing population at risk, relative toxicity of the hazard, in cidence of occupational illness, quantity produced, and trend in use Unfonunately, many of the data were not avail able for every agent, thereby dictating the use of subjective judgments In March 1973, a new NIOSH pnonty list was devel oped using population at nsk and seventy of toxic effect as the only cntena The product of these two numenca) factors represented the overall pnonty factor for each chemical Cntena documents were to be developed on each subject in the order that it occurred on the list. Estimates of population at nsk for each of the 475 agents listed were obtained using national estimates extrapolated from (he 1970 Occupational Hazard Safety of the Chicago Metropolitan Area.* As noted earlier, the approach was modeled after the Delphi process, but because of time and resource constraints a modified approach was used Under contract, a toxicity seventy rating was developed for each of the 475 agents based on a senes of subjective judgments by a panel of 50 occupational health professionals Although the seventy rat ings were to include carcinogenicity and other delayed toxicities, it is probable that the rankings were based more on classical or acute toxicologic factors Data regarding carcin ogenicity were noi as readih available or abundant in 1972 as at present Consequentlv. agents wiih notable chronic ef fects, such as vim! chlonde received low toxicity ratings Lack of knowledge as to possible delaved toxic effects con stantly plagues the assessment of the overall toxicity of chemicals Based on the 1973 pnonty list, a third list was prepared in 1975 by NIOSH staff Three new factors were considered' *45 RSV0033858 PERKINS AND ROSE suspected carcinogenicity or other serious delayed effects, the lack of a federal occupational standard, and new or re vised information regarding the potential hazard of the 475 agents on the 1973 list The top 50 hazardous agents were subjectively ranked, and those remaining agents which were positive for at least one of the new factors were placed m an unranked category Those agents which were negative for all of the three new factors were deleted This list was used by NIOSH until 1977 The three NIOSH priority lists, while serving NIOSH relatively well, have had the following deficiencies The scope of NIOSH priorities has been tod limited While the 1973 list was the largest, it contained only 475 agenls, one industrial process, and several physical agents There was no atiempt to group structurally related chemical compounds. The methods used to generate some data could be im proved, e g , the "Delphi" method used to generate seventy rankings for the 1973 list While subjective opinions are sometimes necessary, they should be avoided whenever ob jective data are available. Greater involvement of affected groups, including in dustry'. unions, and other government agencies, was needed Such involvement, assuming it came from experienced sources, would provide a broader consideration of the need to develop new or revised standards and would help to en sure that NIOSH priorities reflected priorities of other knowledgeable groups and affected parties There was a need for better cooperation between OSHA and NIOSH m the preparation of priority lists. A formalized process with a schedule of events was not used for priority assessment, which in turn did not allow for efficient, orderly planning of research or allocation of funds for that research. Priorities for criteria documents were not identified far enough in advance to allow the NIOSH research and grants program to identify significant research activities, the successful accomplishment of which would result in better recommended standards Toxicity ratings did not place enough emphasis on chronic or delayed aspects .of hazardous agents and, con sequently. did not reflect the best estimate of the need for a standard based on potential harm to workers. The Current Situation Based on the above. NIOSH decided in 1976 that if a new approach to setting priorities was to work, the problems of past pnontv systems would have to be thoroughly eval uated and future problems anticipated and resolved as early as possible Assessment of chemical priorities would have to be undertaken with consideration of at least three new and important factors First, industry is using more and more compounds which are unevaltiated as to toxic potential Hopefully the implementation by EPA of the Toxic Substances Control Act will have some impact on the availability of information for substances in use as well as new ones However, it will take many years to develop the necessary information lo adequately evaluate the potential hazard of the thousands of chemicals now in use Second, the hazardous properties of most compounds for which there are large populations at risk (greater than 100.000 workers! have been documented by NIOSH Future work involves updating these documents with new- informa tion and where necessary revising the recommendations through a separaie effort Many of Ihe chemicals NIOSH must now consider are specialty chemicals involving rela tively small numbers of exposed currem Third population at risk estimates are not available for all commercial chemicals and where estimates are available, they are difficult to keep current To address these problems, NIOSH has determined that criteria documents and recommended standards should be prepared for classes of toxtcoiogically and structurally re lated compounds, and for processes, occupations, or specif ic industries Also, a new document, the Special or Emer gency Occupational Hazard Review will be prepared when the population at nsk factor is not large enough to warrant a cnieria document, or when a response m a shorter time peri od is required These new documents will emphasize meth ods of controlling exposure rather than environmental (workplace airl limits These new initiatives will accomplish several important goals Preparation of criteria documents on chemical classes will increase the population at risk covered by the recom mended standard and result in a more efficient use of NIOSH resources By preparing recommended standards for specific industries processes, and occupations, the health and safety of those workers will be more efficiently protected, and stan dards will be made less burdensome than if several recom mended standards were written for only a percentage of the hazardous agents in a particular industry Coverage of an entire industry will alleviate some compliance problems-- both for industry and OSHA Preparation or Special or Emergency Occupational Hazard Reviews concentrating on work practices will alert employers and employees more rap idly to newly discovered hazards of chemicals being used or produced in the workplace. The current NIOSH priorities program involves a multistep process which includes the use of several data sources and input from various groups Criteria document subjects are selected three to four years m advance of their prepara tion so that the planning and conduct of laboratory research can occur This is especially important if delayed toxicitv or epidemiologic studies are needed Consequently, during 1979. subjects for criteria documents to be completed in 1983 will be selected and it is anticipated that this approximate four-vear lead time will be maintained Figure 1 illustrates the procedures and steps followed in setting priorities for a given vear Nominations from numer ous sources are solicited Information profiles which contain data relating io exposure, toxicitv. production, previous reg ulation process engineering, chemical use and other items deemed necessary for esiabiishmg priorities are then devel oped (see Table 11 Commems are requested via notice in the Federal Register and special letters to interested groups 446 AJPH May, 1979, Vo" 69, No 5 RSV0033859 OCCUPATIONAL HEALTH PRIORITIES TABLE 1 -- Selection Criteria end Information Reported In Profiles Occupational Exposure Patterns Number workers exposed. Duration of exposure. Level of exposure, Exposure to multiple hazards ChemicaifPhysicat Properties Physical state. Form, volatility, stability Reactivity, Structural similanty to known hazards Biolop'cal Effects Chronic toxioty. Acute toxicity, Metabolism and late m body, Organ system(s) involved Production/Use Trends Extent of production. Method of use. Probability ot continued Or expanded use Need for a New or Revised Exposure Standard OSH A Nominations r--* II to NIOSH that associaied with a single chemical or even a class of chemicals The pnmarv issues are possible complexities of exposure to multiple hazards and clear identification of the imended scope of the criteria document Examples of proc ess standards are the rcccntlv promulgated OSHA standard on coke ovens and the current OSHA/NIOSH joint effort for the manufacture and formulation of pesticides Sinnmai i Setting priorities is a difficult task, requiring good infor mation coupled wiihasiuie scientific judgment The mostimportanl factors to be considered are occupational exposure patierns and biological effects of exposure NIOSH has pre pared and recommended to OSHA more than 100 occupa tional health standards covering more than 200 substances including 1500 registered pesticides *1 Of the 20 to 24 recom mended standards to be prepared each yearm the future, an approximately even distribution for chemical classes, indi vidual chemical or physical agents, and occupations or in dustries is anticipated Priorities for fiscal year (FY) 1983 are currentU being developed NIOSH expects to continuously improve us pnorin program in order to keep abreast of the rapid changes in the problems facing the American worker Request for 1 Public Comment Information Profile Development Tentative Selection OSHA Comment Final Selection Approval NIOSH, Director FICL'RE 1--Procedures to Select and Priori!' Rank Subjects for Cri leria Document Development Many useful suggestions including additional subjects for consideration, are usually obtained from this solicitation ef fort. especially from other government agenctes After consultation with OSHA. MOSH then selects 24 criteria document subjects which include classes of chem icals, individual chemicals and physical agents processes, industries, and occupations The task of selecting a process, industry, or occupation is considerably more complex than REFERENCES 1 U S Tariff Commission Svnthetic Organic Chemicals U S Production and Sales 1960-1970 Government Printing Office. Washington DC 2 Howard PH Establishing environmental pnornies for synthetic organic chemicals focusing on the next PCBs EPA Publication No 560-1 15-003 Washington DC pp Jl-65 (July 1975) 3 Toxic Substances Control Act, Public Law 94-469 , 94lh Con gress, October II 1976 4 Stephenson ME An approach to the identification of organic compounds hazardous to the environment and human health, Ecoiov and Env Saf 1 39-48 1977 5 Lmstone l and Turoff M ledsl The Delphi Method. Techniques and Applications Reading M Addison-Wesley Publishing Co 1977 6 Brown NR et al Problem seventy model and implementation plan for occupational safetv and health Am Ind Hyg Assoc 33 815-821 1972 7 Rose ve Reltabiltiv and Utilization of Occupational Disease Data Cincinnati OH DHEW (NIOSH) Publication No 77189 US Dept of Health Education and Welfare. Public Health Service Center for Disease Control. National Instttute for Oc cupational Safety and Health June 1977 8 Occupational Heahh Survev of the Chicago Metropolitan Area Cincinnati OH IS Dept of Health, Education and Welfare. Public Health Service National institute for Occupational Safclv and Health 1970 9 Kendrick MA el al Industrial hygiene survey of metropolitan Denver Pub Hbh Rep 8? 317-322. 1968 10 National Occupational Hazard Survey Volume 1 Cincinnati. OH L S Dept of Health Education, and Welfare, Public Health Service Center lor Disease Control, National Institute for Occupational Safelv and Health. May 1970 11 Occupational Safelv and Health Act. Public Law 91-596. 91st Congress December 29 1970 12 Hosev AD Priorities in developing criteria for "breathing air standards 1 Occup Med 12 43-46. 1970 'Summarv listing of recommendations including plans for fu ture document is available from NIOSH IDCDSD). Room 8A-53. 3600 Fishers Lane. Rockville MD 20837 AJPH May, 1979, Vol 69 No 5 447 RSV0033860 PERKINS AND ROSE APPENDIX TABLE 1--Criteria Documents and Recommended Standards Transmitted to the U.S. Department of Labor Documenl Name Aceiylene Acrylamide Acrylonitrile (Emergency Hazard Review) Aldrm'Dieldrm (Special Occupational Hazard Review) Alkanes Ally 1 Clonde Ammonia Anesthetic Gases Antimony Arsenic Arsenic (revised) Asbestos Asbesios (revised i Asphalt Fumes Benzene Benzene (revised) Benzoyl Peroxide Benzyl Chloride Beryllium Boron Tnfluonde Cadmium Carbary! Carbon Black Carbon Dioxide Carbon Disulfide Carbon Monoxide Carbon Tetrachloride Carbon Tetrachloride (revised) Chlonne Chloroform Chloroform (revised) Chtoroprene Chromic Acid ChromtumVI Chrysene (Special Occupational Hazard Review) Coal Gasification Coal Tar Products Coke Oven Emissions Cotton Dust Cresoland Cresylic Acid Decomposition Products of Fluorocarbon Polymers Dibromochloropropane (Emergency Hazard Review) Dimtro-o-cresol Dusocyanates Dioxane DDT (Special Occupational Hazard Review) Epichlorohydnn Ethylene Dibromide Ethylene Dtchlonde Ethylene Oxide (Special Occupational Hazard Review) Fibrous Glass Fluorides Formaldehyde Glycidyl Ethers Hazardous Materials Hot Environments Hydrazines Hydrogen Fiuonde Hydrogen Sulfide Hydroquinone inorganic Cyanides Inorganic Lead Inorganic Lead (revised) Inorganic Mercurv Inorganic Nickel isopropyl Alcohol Kepone (Emergency Hazard Review) Ketones Logging Malarhion Methyl Alcohol 4.4'-Methyfenebis (2- chloroamhne) (Special Occupational Hazard Review) Methyl Parathion Methylene Chloride n-Alkane Mono Thiols. Cydohexanethiol, and Benzenethiot Nickel Carbonyl (Special Occupational Hazard Review) Nilnc Acid Nilnles Nitroglycerine and EGD Noise Organo-isocyanaies Organotin Compounds o-ToIidint Oxides of Nitrogen Parathion Pesticides Manufacture and Formulation of Phenol Phosgene Polychlorinated Biphenyls Refined Petroleum Solvents Silica Sodium Hydroxide Sulfur Dioxide Sulfuric Acid 1.1 2.2-TetrachIoroethane Tetrachloroethyiene Toluene Toluene Diisocyanate I.I.I-Tnchloroethane Trichloroethylene Trichloroethylene (Special Occupational Hazard Review) Tungsten Compounds Ultraviolet Radiation Vanadium Compounds Vmyl Acetate Vinyl Chloride (Emergency Hazard Review) Vinyl Halides Xylene Zinc Oxide APPENDIX TABLE 2--Criteria Documents and Recommended Standards to be Transmltted to the U.S. Department of Labor FY 1979 Documenl Name Aliphatic Primary Monoamines Brominaied Aromatics Chlorinated Benzenes Coal Liquefaction Cobalt Compounds Fluorocarbons Foundries Furfuryl Alcohol Methyl Chloride Nitrobenzenes Nilrotoluenes Oil Mists Oxalic Acid Paint and Allied Products Manu facturing Plasncsand Resins Manufactur ing Priming Indusiry Radiofrequency and Microwave Radiation Roofing industry Slaughtering and Rendering Plants Styrene S> nthetic Rubber Manufaciunng Talc Welding and Brazing Wood Dusi FY 1980 Document Name Aliphatic dt and poiyammes Aromatic amines Brominated aliphaucs Dtchloropropane Diesel Emissions Dyeing and Finishing Textiles Hexachlorobutadiene Hcxachloroethane Infrared Radiation Manufacture of Non-melallic Pig ments and Dyes Monochloracetic Acid Monochlorocthane Peniachloroethane Pulp and Paper Mills Secondary aliphatic monoamines Tertiary aliphatic monoamines Tetrahydrofuran Tnchloropropane Ultrasonics Vibration, whole body Wood Preserving FY 19*1 Document Name Atkanolammes Aluminum Compounds Caisson and Tunnel Workers Cement Manufacturing and Use Chlorophenols Epoxides Glycol Ethers Glycols Grain Handlers Hexac hlorocycl opentad lene Inorganic Azides Inorganic Chromium (non- hexavalenu Iron Compounds Manganese Compounds Methyl Ethyl Ketone Peroxide Naphthalene Nitrophenols Organic Anhydrides Organophosphosphorus com pounds (excluding pesticides and fire-retardants) Phlhalates Tire Manufaciunng Vinyl Cyclohexene Dioxide FY 1982 Document Name Aliphatic Amines Aluminum Reduction Bisphenol A Copper and its Inorganic Com pounds Dimethyl Sulfoxide Electroplating Ethyl Benzene EthoxyetHanoi Explosives and Fireworks Manu facture Lithium and Compounds Mercaptobenzothiazofes Nilroparaffins Petroleum Refineries Photographic Processing Platinum and Compounds Selenium Solder (Manufacture and Use) Spray Painting/Coating Tellurium Thioureas Titanium and Compounds Tnmeihy I benzenes VmylToluene Xylenols 44g AJPH May. 1979. 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