Document gr35EEoLvzDyX3z6knaja4ge

criteria for a recommended standard . .. . OCCUPATIONAL EXPOSURE TO A~SBESTOS U.S. DEPARTMENT OF HEALTH, EDUCATION, AND WELFARE Public Health Service Center for Disease Control National Institute for Occupational Safety and Health criteria for o recommended standard .... OCCUPATIONAL EXPOSURE TO ASBESTOS U.S. DEPARTMENT OF HEALTH, EDUCATION, AND WELFARE Public Health Service Center for Disease Control National Institute for Occupational Safety and Health 1972 HSM 72-10267 Second Printing PREFACE The Occupational Safety and Health Act of 1970 emphasizes the need for standards to protect the health of workers exposed t o an ever increasing numbe~ of potential hazards at their workplace. To provide relevant data fr om which valid criteria and effective standards can be deduced, the National Institute for Occupational Safety and Health has projected a formal system of research, with priorities determined on the basis of specified indices. It is intended to presen t successive reports as research and . cpidemiologic studies are comp leted and s ampling and analytic methods are developed. Criteria and standards will be reviewed periodically to ensure continuing protection of the worker. I am pleased to acknowledge the contributions to this first report on asbestos by members of my staff, and the valuable constructive comments by the Review Consultants on Asbestos. A list of these contri- butors and reviewers appears on pages ii i and iv. The contributions of others are also acknowledged: Dohrman H. Byers* Bureau of Occupational Safety and Health Cincinnati, Ohio Gl en W. Sutton* Bur eau of Occupational Safety and Health Cincinnati, Ohio Andrew D. Hosey* Bureau of Occupational Safety and Health Cincinnati, Ohio Richard E. Kinser Bureau of Occupational Safety and Health ** Cincinnati, Ohio Bobby J. Gunter, Ph.D.~ Bureau of Occupational Safety and Heal th** Cincinnati, Ohio John L. Holtz Bureau of Occupational Safety and Health** Cincinnati, Ohio Roger A. Nelson* Bureau of Occupational Safety and Health Cincinnati, Ohio Edward J. Baier Occupational Health Program Pennsylvania Department of Health Paul Gross, M.D. John C. Lumsden Graduate School of Public Health North Carolina State University of Pittsburgh Board of Health Morris Kleinfeld, M.D. New York State Department of Health Irving J, Selikoff, M.D. Mount Sinai Schoalof Medicine City University of New York Douglas H. K. Lee, M.D. National Institute of Environmental Health Sciences bDir,ecto~r, -Nat.ioDna~d~t_ut_e for Occupational Safety and Health former staff **now National Institute for Occupational Safety and Health ii REVIEW COMMITTEE NATIONAL INSTITUTE FOR OCCUPATIONAL SAFETY AND HEALTH Howard E. Ayer Assistant Director, Division of Field Studies and Clinical Investigations John V. Crable Acting Chief, Laboratory of Physical and Chemical Analysis Bobby F. Craft, Ph.D. Acting Director , Division of Technical Services Lewis J. Cralley, Ph.D. Office of the Associate Director, Cincinnati Operations Lorice Ede, J.D . Office of Res earch & Standards Development Edward J. Fairchild, Ph.D. Acting Associate Director, NIOSH Cincinnati Operations William M. Johnson, M.D. Associate Director, Division of Field Studies and Clinical lnvestiaationa Jeremiah R. Lynch Acting Deputy Director, Division of Laboratories and Criteria Development Raymond T. Moore, M.D. Associate Director, NIOSH Washington Operations Charle~ H. Powell, Sc . D. Assistant Director, NIOSH for Research and Standards Development Warren L. Smith, M.D. Division of Field Studies and Clinical Investigations Herbert E. Stokinger, Ph.~. Division of Laboratories and Criteria Development Joseph K. Wagoner, S.D. Hyg. Director, Division of Field Studies and Clinical Inveatigations iii NIOSH REVIEW CONSULTANTS ON ASBESTOS W. Clark Cooper, H.D. Professor in Residence Occupational Health Division of Environmental Health Sciences University of California School of Public Health Berkeley, California Duncan A. Holaday Research Professor Mount Sinai School of Medicine City University of New York New York, New York George W. Wright, H.D. Head, Department of Medical Research St. Lukes Hospital Cleveland, Ohio iv CRITERIA DOCUMENT: RECOMMENDATI ONS FOR AN OCCUPATIONAL EXPOSURE STANDARD FOR ASBESTOS Table of Cont ents PREFACE REVIEW COMMITTEES I RECOMMENDATIONS FOR AN ASBESTOS STANDARD Section l - Environmental Section 2 - Me.dical Section 3 - Labeling Section 4 - Personal Protective Equipment and Clothing Section 5 - Apprisal of Employees of Ha~ards frOlll Aabestos Section 6 - Work Practices Section 7 - Monitoring & Recordkeeping Requirements II INTRODUCTION [II BIOLOGIC EFFECTS OF EXPOSURE Extent of Exposure Early Historical Reports Epidemiological Studies Animal Toxicity Correlation of Exposure and Effect IV ENVIRONMENTAL DATA V DEVELOPMENT OF STANDARD Baai1 for Previous Standards U. S. Emergency Standard Bai for Recommended Standard SU!lllUry VI COMPATIBILITY WITH EMISSION STANDARDS VII REFERENCES VIII APPENDIX I - Air Sampling Method IX APPENDIX II - Numerical Hazard llatin& Syat. . X APPENDIX Ill - Material Safety Data Sheet I. RECOMMENDATIONS FOR AN ASBESTOS STANDARD The National lnetitute for Occupational Safety and Health .(NIOSH) recommends that worker expoeure to asbestos duet in the workplace be controlled by requiring compliance with the foll owing sections. Control of worker exposure to the limits stated will prevent asbestosis and more adequately guard against asbestos-induced neopl~sms . The standard is amenable to techniques that are valid, reproducible, and available to industry and governmental agenc1es. It will be subject to review and will be revised as necessary . Section l - Environmental (work place air) (a) Concentration Occupational exposure to airborne aRbestos dust shall be controlled so that no worker shall be exposed to nore than 2.0 asbestos fibers per cubic centimeter (cc) of air based on a count of fibers greater than 5 micrometers ()5.).1111) in length {(determined by the membrane filter method at 400-450X magnification (4 millimeter objective) phase contrast illumination, as described in Appendix I)), determined aa a time-weighted average {TWA) exposure for an 8-hour work day, and no peak concentration of asbestos to which workers are expoeed shall exceed 10.0 fibere/cc75.)llD as determined by a minimum sampling time of fifteen minutes. {b) SSD1pling Proceduree for sampling, calibration of equipment, and analyeis of aebestos samples shall be as provided in Appendix I. (c) It is recommended that this Section I become effective two years after promulgation as a standard, and that until the date of 1-1 publication, the present emergency standard for exposure to asbestos dust (29 CYR 1910.93a) shall be in effect, This period is believed necessary to permit installation of necessary engineering controls. 1-2 Section 2 - Medical Medical surveillance is required, except where a variance from the medical requirements of this proposed standard have been granted, for all workers who are exposed to asbestos as part of their work environment. For purposes of this requirement t he term "exposed to asbestos" will be interpreted as referring to time-weighted average exposures above 1 fiber/ cc or peak exposures above 5 fibers/cc. The major objective of such surveillance will be to ensure proper medical management of individuals who show evidence of reaction to past dust exposures, either due to excessive exposureo or unusual susceptibility. Medical management may range from recommendations as to job placement, improved work practices, cessation of smoking, to specific therapy for asbestos-related disease or its com plications. Medical surveillance cannot be a guide to adequacy of current controls when environmental data and medical examinations only cover recent work experience because of the prolonged latent period required for the development of asbestosis and neoplasms. Required components of a medical survei llance program include periodic measurements of pulmonary function (forced vital capacity (FVC)), and forced expiratory volume for one second (FEV1), and periodic chest roentgenograms (postero-anterior 14 x 17 inches). Additional medical requirement components include a history to describe smoking habits and details on past exposures to asbestos and other dusts and to determine presence or absence of pulmonary, cardiovascular, and gastrointestinal symptoms, and a physical examination, with special attention to pulmonary rales, clubbing of fingers, and other signs related to cardiopulmonary eyetema. 1-3 Chest roentgenograms and pulmonary function tests will be performed at the employer's expense, at least every 2 years on all employees exposed to asbestos. These tests will be made annually to individuals, (1) who have a history of 10 or more years of employment involving exposure to asbestos or, (2) who show roentgenographic findings (such as small opacities, pleural plaques, pleural thickening, pleural calcification) which suggest or indicate pneumoconiosis or other reactions to asbestos, or (3) who have changes in pulmonary function which indicate restrictive or obstructive lung disease. Preplacement medical examinations and medical examinations on the termination of employment of asbestos exposed workers are also required. I-4 Section 3 - Labeling (a) A warning label for asbestos as shown in Figure l ehall be used. (b) Numerical designations indicate the following: (i) 4 Health Hazard (color code, blue) . Inhalation may cause asbestosis, pleural or peritoneal mesothelioma, or lung cancer . (ii) O Fire Hazard (color code, red). Asbestos is non-fl&J!IDable and has negligible vapor pressure, volatility, flash point, and explosive limits. (c) The details of the numerical hazard rating system are found in Appendix II. 1-3 ASBESTOS HARMFm..: May Cause Delay ed Lung Injury (Asbestosis, Lung Cancer). DO NOT BREATHE DUST Use only with adequate ven tilation and approved respiratory protec tive devices. I- 6 Section 4 - Personal Protective Equipment and Clothing 11\is section shall appl~ whenever a variance from the standard set in Section I is granted undeT provisions of the Occupational Safety and Health Act.* Use of respirators can be decided on the basis of timeweighted average or peak concentration. When the limits of exposure to asbestos dust prescribed in paragraph (a) of Section 1 cannot be met by limiting the concentration of asbestos dust in the work environment, an employer must utilize as provided in subsections (a) and (b) of this Section a program of respiratory protection and furnishing of protective clothing to effect the required protection of every worker exposed, (a} Respiratory Protection (i} For the purpose of determining the class of respirator to be used, the employer shall measure the atmospheric concentration of airborne asbestos in the workplace when the initial application for variance is made and thereafter whenever process, worksite , climate or control changes occur which are likely to affect the asbestos concentration. The employer shall test for respirator fit and/or make asbestos measurements within the respiratory inlet covering to insure that no worker is being exposed to asbestos in excess of the standard either because of improper respirator selection or fit. (ii) ~ noted above, the use of respirators and protective clothing can be decided on the basis of either time-weighted average or peak concentrations. For determining usage or compliance, the peak concentration of 10 fibers/cc is preferable. *Variance procedures will not be required for emergency and occasional short-term exposures in excess of the environmental standard. However, the use of respirator equipment as indicated in this Section (4) will be required under condition& in excesa of the 1tandard. I-7 (iii) For an atmosphere containing not more than 10 fibers/cc greater than 5 pm in length over an 8-hour average or more than 50 fibers/cc over any 15 minute period, a reusable or single use filter-type air-purifying re8pirator, operating with a negative pressure during the inhalation phase of breathing, approved under the provisions of 30 CFR 14 (Bureau of Mines Schedule 2ll!) or valveless respirators providing equivalent protection shall be used. (iv) For an atmosphere containing noc more than 100 fibers/cc greater than 5 pm in length over an 8-hour average or more than 500 fibers/cc over any 15 minute period, a powered air-purifying positive-pressure respirator approved under the provisions of 30 CFR 14 {Bureau of Mines Schedule 21B) sh~ll be used. (v) For an atmosphere containing more than 100 fibers/cc greater than 5 pm in length over an 8-hour average or over 500 fibers/cc for any period in excess of 15 minutes, a type C posit i ve-pressure supplied air respirator approved under the provisions of 30 CFR 12 {Bureau of Mines Schedule 198) shall be used. (vi) The employer shall establish a respirator program in accordance with the requirements of the American National Standard for Respiratory Protection Z88.2--1969. (b) Protective Clothing (i) The employer shall provide each employee subject to exposure in a variance area with coveralls or similar full body protective clothing and hat, which shall be worn during the working hours in areas where there is exposure to asbestos dust. 1-8 (ii) The employer shall provide for maintenance and laundering of the soiled protective clothing. which shall be stored, transported and disposed of in sealed non-reusable containers m.ark.ed "Asbestos-Contaminated Clothing" in easy-to-read letters. (iii) Protective clothing shall be vacuumed before removal. Clothes shall not be cleaned by blowing dust from the clothing or shaking. (iv) If laundering is to be done by a private contractor. the employer shall inform the contractor of the potentially harmful effects of exposure to asbestos dust and of safe practices required in the laundering of the asbestos-soiled work clothes. (v) Resin-impregnated paper or similar protective clothing can be substituted for fabric type of clothing . (vi) It is recommended that in highly contaminated operations (such as insulation and textiles) provisions be made for separate change rooms. I-9 Section 5 - Apprisal of Employees of Hazards from Asbestos Each employee exposed to asbestos shall be apprised of all hazards, relevant symptOlllS, and proper conditions and precautions concerning use or exposure. Each exposed worker shall be informed of the in!onnation which is applicable to a specific product or material containing 5% or more asbestos (see Appendix Ill for details of information required). The information shall be kept on file and readily accessible to the worker at all places of employment where asbestos materials are manufactured or used in unit processes and operations. It is recommended, but not required, that this information be provided for asbestos processes and operations where the asbestos content is less than 5%. Information as specified in Appendix III shall be recorded on U. S. Department of Labor Form OSHA-20, "Material Safety Data Sheet", (see page X-3 and X-4), or a similar form approved by the Occupational Safety and Health Ad~inistration, U. S. Department of Labor. 1-10 Section 6 - Work Practices (a) Asbestos cement, mortar, coatings, grout, and plaster shall be mixed in closed bags or other containers. (b) Asbestos waste and scrap shall be collected and disposed of in sealed bags or other containers. (c) All cleanup of asbestos dust shall be performed by vacuum cleaners or wet cleaning methods. No dry sweeping shall be performed. I-11 Section 7 - Monitoring and Recordkeeping Requirements ~ployere will be required* to maintain records of environmental exposure to asbestos based upon the following environmental sampling and recordkeeping schedule. Personal exposure samples will be collected at least annually by specific maximum-risk work operations from a number of employees. The first sampling period will be completed within 180 days of the date of this standard. These selected samples will be collected and evaluated as both time-weighted and peak concentration values. The personal sampling regime shall be on a quarterly basis for maximum-risk work areas under the foll owing conditions: (a) The environmental levels are in excess of the standard. (b) There are other conditions existing that necessitate the requesting of a variance from the Department of Labor. Records of the type of respiratory protection in use during the quarterly sampling schedule must also be maintained. Quarterly sampling, monitoring and recordkeeping will be required only until environmental levels comply with the standard. *Except where a variance for monitoring and recordkeeping has been granted. 1-12 II. INTRODUCTION This report presents the criteria and the standard based thereon which were prepared to meet the need for pr eventing occupational diseases arising from exposure to asbestos dust. The necessary relevant data are made available for use by the Secretary, Department of Health, Education, and Welfare in accordance with t he provision of the Occupational Safety and Health Act of 1970 requiring the development of criteria by "The Secretary, Department of Health, Education, and Welfare ... on the basis of such research, demonotrations, and experiments and any other information available to him ... to effectuate the purposes of this Act." . , " by providing medical criteria which will assure insofar as practicable that no employee will suffer diminished health, functional capacity, or life expectancy as a result of his work experience" ... The National Institute for Occupational Safety and Health (NIOSH), after a review of data and consultations with others, formalized a system for the development of criteria upon which standards can be established to protect the health of workers from exposure to hazardous chemical and physical agents. It should be pointed out that any recommended criteria for a standard should enable management and labor to develop better engineering controls and more healthful work practices and should not be used as a final goal. These criteria for a standard for asbestos dust are the first of the criteria developed by NIOSH. The cri t eria and standard speak only to the processing, manufacture, and use of asbestos products as applicable under the Occupational Safety and Health Act of 1970. 11-1 The occupational safety and health aspects of the mining and mill ing of asbestos ores a r e covered by provisions of the Federal Metal and Nonmetallic Mine Safety Ac t (30 US.C. 725 et seq.) under which provisions the Bureau of Mines has promulgated applicable regulations. Relevant data , however, bearing on the safety and health hazards from exposure to asbestos dust in the mining and milling of ores were consi de r ed in this document. These criteria were developed to assur e that the standard based thereon would, (1) protect against asbestosis and asbestos-induced neoplasms, (2) be amenable to techniques that are valid, reproducible , and available to industry and official agencies, and (3) be a t tainable with existing technology. The recommended standa rd is designed pr i marily to prevent asbestosis. For other diseases associated with asbestos, there is insufficient infonn~tion to estab lish a standard to prevent s uch diseases in clud i ng asbestos- i nduced neoplasms by any all-inclusive limit other than one of zero. Neve rt heless, a safety fa~tor has been included in ar riving at the concentration level that will reduce the t otal body burden and should more adequately guard against neoplasms. Asbestos has been min ed , milled, processed, and used for many years, and as a result, a number of workers have experienced significant accumulative exposure t o asbestos dust over a wo rking lifetime. It has been recognized that biological monitoring (by periodic chest roentgenograms) and removal from further exposure after initiation of fibrosis, calcification or neoplaeia will not absolutely prevent II-2 further progression of asbestosis or the clinical development of neoplasms. Therefore, it is absolutely essential that a low level of concentration be set to preclude the initiation of diseases resulting from exposure to asbestos, And of necessity, any prol on ged delay in the establishment of the standard may require a more stringent standard in the future to assure the reduced t otal body burden of employees which is necessary to protect their s afety and health. 11 -3 III. BIOLOGIC EFFECTS OF EXPOSURE TO ASBESTOS Asbestos is a generic term that applies to a number of naturally occurring, hydrated mineral silicates incombustible in air and separable into filaments. The most widely used in industry in the United States is chrysotile (3Mg0.2Si02.2H20), a fibrous form of serpentine. Other types include amosite (FeMg)Si03); crocidol ite (NaFe(Si03)2.FeSi03H20); tremolite (ca 2Mg 5siao22 (oH) 2); anthophyllite (MgFe)7Siao22 (0H)2); and actinolite (Ca0.3(MgFe)0.4Si02). Extent of Exposure Almost one million tons per year of asbestos are used in the United States. In 1965, approximately 74 percent of the asbestos produced was used in the construction industry (532,300 tons) while 26 percent was used in non-construction industries (187,400 tons). Approximately 92 percent of the half million tons used in the construction industry is firmly bonded, i.e., the asbestos is "locked in" in such products as floor tiles, asbestos cements, and roofing felts and shingles; while the remaining 8 percent is friable or in powder form present in insula- 1 tion materials, asbestos cement powders, and acoustical products. As expected, these latter materials generate more airborne fibers than the firmly bonded products. The 187,400 tons of asbestos used in nonconstruction industries in 1965 were utilized in such products as textiles, friction material including brake linings, and clutch facings, paper, paints, plastics, roof coatings, floor tiles, and miscellaneous other products. Mining and milling of asbestos in the United States is a small industry, employing fewer than a thousand workers. The health and safety III-1 aspects of mining and milling operations are not covered un der the Occup ati onal Safety and Health Act of 1970. The construction industry has, i n recent years, applied asbestos insulation materials by spraying, a me thod of application that generates more airborne asbestos fibers than older conventi ona l methods. This techniq ue at present utilizes only a small percentage of the total asbes tos produced and its use is decreasing. There are approximately 40,000 field insulation workers in the United St ates who are exposed to asbestos dust . The activities of these workers cause secondary exposures to an estimated three to five milli on other building construction and shipyard workers. 2 Since the dust exposure to the individual worker is extremely variable and the n\DDber of asbestos workers at any one location is small, the primary and secondary asbestos dust exposures to all workers have never been satisfactorily estimated. An estimated 50,000 workers are involved in the manufacture of asbestos-containing products. This figure does not include secondary manufacture of products whi ch contain asbestos, such as electrical or thermal insulation, or products which include previously manufactured components containing asbestos.3 The following information, furnished by the Pennsylvania Division of Occupational Health, shows the number and variety of plants using asbestos in which potential exposures can occur. These figures are based on a survey of a total of 18,439 manufacturing plants in that 111-2 State as of August 22, 1969, and represents about 1.4 percent of all manufacturing oper~ti ons in Pennsylvania. Service facilities such as garages are not included. No. of Plants Insulation, including cutting > drilling , and tape manufacture Manufacturing and processing Brakes and friction Cement, clay Miscellaneous* 75 16 10 18 146 *Gaskets Signs Safety equipment Laminated material Paint and roofing materials Shipbuilding and shipbreaking Impregnating resin and urethane Textile Undercoating material Ironing board covers Fl ooring TOTAL 26 5 III-3 Early Historical Reports The widespread use of asbestos fibers did not begin until the last quarter of the nineteenth century. 2 With the increasing use of asbestos materials and increasing reports of asbestos related disease there developed concern over the role of these minerals as factors in human disease. Differentiation o f the type of asbestos fiber was not made in most studies related to occupational exposure. In the United States the exposures of greatest concern usually involve more than one type of fiber, although chrysotile predominates. To refine our knowledge of the biological actions of asbestos, it is imperative that the character of the exposure as to concentration, size, and type of fiber be known. At present, data of this complexity are / scanty or often non-existent with respect to human exposure. The first record of a case of asbestosis was report e d in England by Montague Murray in 1906. 4 The first complete description of asbestosis and of the "curious bodies" seen in lung tissue appeared in 1927 when Cooke5 reported on a case of asbestosis and McDonald6 reported on the same and another case. Each a uthor gave reasons for believing that these "curious bodies" originate frooi asbestos fibers that reach the lungs. Many of the people exposed to asbestos dust develop the disease "asbestosis" if the dust concentration is high or the duration of their exposure is long. Thia has been documented by the following studies: Merewether and Price, 1930; Fulton ~ .!!_., 1935; and Dreessen et al. , 1938. In 1918, Hoffman 7 reported that it was the practice of 111-4 American and Canadian insurance companies not to insure asbestos workers due to the assumed health-injurious conditions of that industry. In 1917, Pancoast, Miller and Landis 8 reported on X-ray appearances of pneumoconiosis in 15 individuals exposed to asbestos. Mills' publication9 in 1930 was the f i rst report on a case of asbestosis published in the United States , and in that same year, Lynch and Smith10 reported on "asbestosis" bodies * found in the sputum of asbestos workers. In Merewether's review of asbestosist11 emphasis was placed on the relation of asbestosis to dusty working conditions . The c linical aspects of asbestosis are well documented. Gloyne 12 discussed the pathology of asbestosis and methods for diagnosing asbestos.bodies and asbestosis. Selikoff and Hammond13 analyzed 1,975 autopsies in three large New York City hospitals and found asbestos bodies in 942 (47.7%). Broadly considered, 40 percent of housewives, 50 percent of "white collar" males, and 50 percent of "blue collar" males showed asbestos bodies; but males who had a history of shipyard or construction work had higher incidence of asbestos bodies, i.e., 90 of 129 cases or 70 percent. Selikoff ' s observations also suggest that asbestos bodies were as frequently present 38 years ago as now. Although a large percentage of the lungs of adult urban dwellers may be found to contain ferruginous bodies (depending on the method of examination), the significance of this is as yet unknown. *11Ferruginous bodies" is a more descriptive term. This and other aspects of the biologic effects of asbestos ari well documented in the Annals of the New York Academy of Science. Ill-5 The core fibers have not been systematically identified to indicate how many are asbestos bodies, and there are little data bearing on possible health effects associated with the low concentrations of fibers found in ambient air. An abnormality, occurring with unusual ly greater frequency in populations exposed to inhalation of asbestos fiber, is that of localized thickening, or plaques, of the pleura with or without calcification of the plaques. The role o f the asbestos fiber in this manifestation is not clear. The medical aspects of exposure to asbestos and the development of the occupational disease, asbestosis, are characterized by: (1) A pattern of roentgenographic changes consistent with diffuse interstitial fibrosis of variable degree and, at times, pleural changes of fibrosis and calcification. (2) Clinical changes including fine rales and finger clubbing. These may be present or absent in any individual case. (3) Physiological changes consistent with a lung disorder. (4) A known history of occupational exposure to airborne asbestos dust. In general, a considerable time lapse between inhalation of the dust and appearance of changes as determined by X-ray. The several clinical abnormalities listed above appear to occur with unusual frequency in those environments where airborne asbestos fibers, often in association with other substances, exist. One of these abnormalities, a diffuse chronic inflauunation and scarring 111-6 of the lung, is the one recognized early in this century and referred to as "asbestosis, 11 Epidemiological Studies Harrieel4 in 1968 suggested that first impressions would lead one to believe that only workers continuously exposed to asbestos are at risk of developing asbestosis, however, a number of trades experiencing intense intermittent exposures are also suspect. These other trades involve work "'1th asbestos insulation in confined spaces onboard ship. Work in these trades has been accepted by the Pneurooconiosis Panel of the United Kingdom as associated with asbestosis. Selikoff, 15 however, in a study of 232 former insulation plant employees reported positive X-ray findings among individuals having had known exposures to asbestos as short ea one day (Table XXVII). In the late 1940'a a frequency of bronchogenic cancer greater than that expected on the basis of the general male population was manifest among persons who worked in the manufacture of asbestos products. 16 This excess of bronchogenic cancer was als o demonstrated among a group of workers in the United States ex-posed to airborne asbestos fibers in the installation of insulation. 17 ' 18 Among 632 asbestos insulation installers observed from 1943 to 1967 there were 99 excess deaths (above that ex-pected on the basis of the U. S. white male population) for three types of malignancies-- bronchogenic (63), gastrointestinal (26) and all other sites combined (10). Elmes and Simpson19 recently reported findings of similar magnitude among men employed as insulators and pipe coverer& in Belfaat. Newhouse 20 found an excess of lung cancer 111-7 in a study of over 4,500 male workers employed at an asbestos factory making both textile and insulation materials. This excess of lung cancer was demonstrated among those workers with jobs which entailed heavy exposure irrespective of the duration of employment. More recent observations by Selikoff in the United States indicate a lung cancer risk for workers exposed to amosite asbestos in the production of insulation material. 21 The possibility that the carcinogenic role of asbestos is solely that of a cocarcinogen has been suggested by Wright. 2 This suggestion stems from the observation by Selikoff and associates 17 that among 370 asbestos insulators, exposure to asbestos dust does not greatly increase the risk of bronchogenic cancer in the absence of regular cigarette smoking. More recent observat ions among this same group of workers,22 however, demonstrate that this interpretation is largely a function of sample size as one lung cancer death vs. 0.02 expected was observed among non-smokers as contrasted with 27 vs. 2.83 expected among cigarette smokers. Moreover, Decoufle23 demonstrated that the excess of lung cancer mortality among several subgroups of retired asbestos workers could not be explained by cigarette smoking alone. Concerning mesothelioma, 80 percent of the cases studied in South Africa and the United Kingdom have been shown to have an occupational or para-occupational association with asbestos fibers. 2 In the United States, Selikoff and co-workera have reported the occurrence of 14 deaths from mesotheliomas among 532 asbestos insulation workers studied in retrospect from 1943 to 1968 compared to no death which III-8 would be expected in the same number of s i milRr individuals in the general population. 17 18 Informa.tion is i nsufficient at this time to set an exposure standard (other than zero) which would assure prevention of mesothelioma in all workers, as the disease may occur following a verj limited exposure 20-30 years ear.lier. An increased rate of occurrence of mesothelioma of the pleura or peritoneum was reported in some populations in 1959 and in subsequent years. The possibility that asbestos may play a role in this distribution has been raised. Investigations of the distribution of mesothelioma in populations occupationally exposed to asbestos indicate a strong relationship between exposure to asbestos fiber and the presence of mesothelioma.18,20,24,25 Neoplasms, such as mesothelioma, may occur without radiological evidence of asbestosis at exposure levels lower than those required for prevention of radiolo gically evident asbestosis. This may be of particular importance when consideration is given to short-term, high levels of exposure, and may result i n the development of mesothelioma before or after completion of a norm.al span of work either in or out of the asbestos industry. This is illustrated by several case studies, including two cases of malignant mesothelioma, one a "family" and the other a "neighborhood" case. 26 In another "family" case, a woman washed the overalls of her three daughters at home; all three daughters worked for an asbestos company with possible heavy exposures to asbestos. III-9 The time lapse between onset of exposure and mesothelioma in 344 deaths among asbestos insulation workers was studied, Mesothelioma developed after a longer lapse of time from onset of exposure t O- asbestos than was the case in the devel opment of asbestosis (Table XXVIII). 15 Knox 27 reported 4 cases of mes o thelioma in men and women with less than 10 years exposure, one with only seven months exposure, with the latent time for the development of the mesothelioma from 23 to 53 years. D. L. Cran 28 indicated that mesothelioma did occur in cases of asbestosis, but that in most cases of mesothelioma that he had seen, the occurrence of asbestosis was not found. He postulated that the difference being the long periods of exposure required to produce asbestosis, while mesothelioma could occur long after a short intensive exposure. The 27 cases of mesothelioma in children under 19 years of age indicates the latent time period for develqpment of mesothelioma I may be shorter than first estimated.29 Fifteen cases 30 of pleural mesothelioma associated with occupational exposure were reported in Australia . The relationship between the mesothelioma development and asbestos was based upon occupational histories and finding of asbestos bodies in the tissue. ln some of these cases, the relationship to occupational exposure could not be developed with any degree of certainty, but included patients whose exposure was as short as six months. No patient was regarded clinically or radiologically as suffering from asbestosis; one person had pleural plaques that were radiologically visible. III-10 Stumphius,31 between 1962 and 1968, f ound 25 cases of mesothelioma on Walcheren Island. Of these cases , 22 h ad been employed in the shipyard trades. Stumphius noted that the shipyard employed abou t 3000 men. This would result in a rate of mesothelioma of approximately 100 per 100,000 males per year. He also noted that th~ rate for Dutch provinces with heavy industry is 1.0 per 100,000 per year.31 In the same study, examination of sputum from 277 shipyard workers showed that 60% had asbestos bodies. The frequency varied from 39% of those with no obvious exposure to 100% among those with slight but definite asbestos exposure. McEwen 32 found that the incidence of mesothelioma in Scotland was similar to that found in other part~' o f the United Kingdom and confirmed the association between the deve l opment of the tumor and occupational exposure to asbestos. In 1968 Stumphius and Meyer33 concluded that asbestos exposure may lead to asbestosis, to carcinoma of the lungs and digestive tract, and to mesothelioma. They further stated that there may be no indication of definite exposure to asbestos. It must be pointed out that a clear picture of the relationship between the type of asbestos and the production of asbestosis , neoplasms, and mesotheliomas is not defined in the exposures reported. In many cases mixed exposures have occurred; e . g., the cases from the Naval dockyards in Great Britain where exposures have occurred in unknown amounts to crocidolite and amosite . III-11 Animal Toxicity Experimental Animal Studies. Experimental exposure of animals to asbestos has been in progress for more than 40 years. During this time, a precise experimental animal model, from which could be derived dose-response relationships that could be used in estimating the appropriate value for a work place air standard has not yet been reported. The rate of development of asbestotic pulmonary fibrosis and of induction of pleural mesotheliomas is so slow that the animals die before onset of the condition. Accordingly, to develop either condition, experimenters have had to use inordinately high exposure levels or abnormal modes of administration or both, t h us nullifying the animal model. The classical demonstrations of diffuse pulmonary fibrosis in guinea pigs with accompanying asbestos bodi es by Gardner and Cununings34 and by Vorwald !!~35 became possible only by using fiber levels of from 1,400 to 5,000/cc (39 million to 138 million fibers/cubic foot); and the uniform production of mesotheliomas in rats by Wagner and Berry36 was attained only after administering the asbestos by intrapleural injection at the extraordinarily high dose of 20 mg. Stanton et al. 37 were unable, even when aided by chemical means, to induce neoplasms of any type in a tumor-susceptible strain of rats at low dosages of asbestos (type unspecified); but Gross et a1. 38 did produce in rats malignant pulmonary tumors of several types from exposure at very high doses (ca. 22,000 fibers/cc 86 mg/m3) of chrysotile asbestos that had been hammermilled to an increase in cobalt of 145%; nickel, 82i.; and chromium, 34~. 111-12 Differences in animal responses to "harsh" and "soft" chrysotile asbestos were seen by Smith~ al.39: granulomatous and fibrous pleural adhesions were thicker, and pleural mesotheliomas appeared more rapidly in response to harsh chrysotile. (Harsh chrysotile was characterized as appearing in thicker bundles and was hydrophobic whereas the soft chrysotile was hydrophilic). There are no experimental animal dose-response data that can be used in estimating a work place air standard for asbestos. Contributions to Occupational Exposure Standards from Animal Studies. Of possible value in estimating occupational exposure limits are data regarding the relative disease-producing potency of the various forms and types of asbestos. Wagner40 found in the three species exposed (guinea pigs, rabbits, and monkeys) that amosite produced more marked interstitial fibrosis than chrysotile and the lesions occurred earlier. No statement on relative potency of crocidolite could be made because of the impure nature of the test specimen. On the other hand, amosite was found by the same investigator 36 to be about one-half as potent in the production of mesotheliomas in rats as chrysotile and crocidolite, if numbers and rate of production are used as indicators. An incidental finding was no evidence for difference in effect between natural and oil-extracted forms of crocidolite, a subject considered as a possible factor in the induction of asbestos cancers. 41 Naturally Occurring Effects in Lower Animals. No evidence appears to exist that domestic or wild animals can provide criteria for standards, 111-13 or for controlling asbestos emissions, although a few confirmatory reports have been made that asbestosis can occur in such animals . Webster 42 has demonstrated fibrosis with associated asbestos bodies and fibers in wild rodents in South Africa, in one of a troop of baboons, and in two donkeys that had either worked in, or lived around, crocidolite mines or mills. And Schuster43 reported pulmonary asbestosis, without asbestos bodies, in a dog that had lived for about 10 years in a London asbestos factory as a rat catcher. The magnitude or the type of exposure was not reported in any instance. Factors Influencing Pathogenesis-- Experimental Animal. Experimental animal studies have been informative in elucidating the factors that modify or expl ain the biologic action of asbestos. At least six factors have been investigated: (1) fiber length and bundle size; (2) cytotoxicity; (3) red cell hemolytic ~ activity; (4) asbestos hydrocarbons; (5) morphologic changes; and (6) trace metals in asbestos . (1) Fiber length and bundle size. The relation between length of fibers and of fibers to motes (nonfibrous particles) and asbestos induced disease has been one of continuing experimental inquiry . Gardner and Cummings 34 and Gardner44 found that longer fibers appeared to have a greater fibrogenic effect, although fibrosis developed in animals exposed to dusts which were composed of but one to 1.5 percent fibers. The high exposure concentration of 100 mppcf (ca . 3,600 fibers/cc) makes any decision on the relative potency of fibers vs. motes virtually impossible; however, when animals were exposed to short-fiber asbestos dust, although the type and rate of tissue r eaction 111-14 were essentially the same, the extent of i nvolvement was very much less than that of longer fibers. Inasmuch as exposure concentrations in these comparable studies were about the same, the conclusion can reasonably be made that longer fibers are more fibrogenic, but that the motes are not without fibrogenic potential. In experiments with rabbits, King, Clegg, and Rae 45 using Rhodesian chrysotile fibers averaging 2.5 pm and 15 ;.un in length, concluded that the shorter fibers produced generalized interstitial fibrosis, whereas the longer fibers produced nodular lesions. This finding was not confirmed by one of the investigators (King) in another animal species. 46 Later repetition of the investigations, with "fine" chrysotile and amosite (85% and 82'.6X respectively, less than 1 ;.un in length) by I I Wagner40 yielded definite fibrosis with both dusts, thus confirming the original work of Gardner that short fibers or motes have fibrogenic potential. This experimental work has significance for industrial air standards in indicating the need to support additional research on the "greater than 5 }llD in length" specific requirement and the more general relation of fiber length to cancer induction, which has never been determined experimentally. (2) Cytotoxicity. Both chrysotile and crocidolite were found to be markedly toxic to guinea pig macrophages in vitro. 4 7 The fibrous fraction showed a high, and the particulate, a moderate toxicity, thus providing evidence in conformity wi th the relative biologic potencies of fibrous and nonfibrous forms found in in vivo studies. 111-15 (3) Hemolytic Activity. In a similar e f fort to discover the initial stages of biologic activity of asbestos, and in particular to account for the iron-staining character of asbestos bodies, the hemolytic action of four asbestos types was determined. Whereas chrysotile proved to be potently hemolytic, crocidolite, amosite and anthophyllite were either completely inactive or only weakly. 48 No at t empt was made, however, to _correlate the greater hemolytic activity of chrysotile with the ironstaining intensity of its asbestos bodies relative to those from other asbestos fonns. (4) Asbestos Hydrocarbons. As chrysotile proved to be most adsorptive of iron, so was it most adsorptive of benzpyrene; compared with 100% adsorption for chrysotile, crocidolite and amosite absorbed from solution 40% and 107. respectively.49 On this basis, chrysotile should prove the most potent cocarcinogen of the three forms if its action is mediated through exogenous benzpyrene. Tilis has not been demonstrated as yet in humans. A 10% desor p tion from chrysotile by serum in three days was demonstrated, 49 a condition considered an essential first step in hydrocarbon carcinogenesis. (5) Morphologic Changes. Electron microscopy of animal tissues has greatly enlarged understanding of the processes that occur following contact of pulmonary cells with asbestos. Examination by light, phase, and electron microscopy by Suzuki and Churg49 of subcellular tissue of hamsters intratracheally exposed to chrysotile revealed the successive steps that occurred in th~ cytoplasm of certain pulmonary cells. Particularly informative for the mode of chrysotile action was the description of the formation and the ultrastructure of the asbestos III-16 body, and the indication that instilled fibers tend t o split longitudinally with time. The suggestion that ch rysotile breaks up into short fragments on the evidence that the majority of the fibers found in the alveoli were less than one-sixth the injected length, one and two years later, is open to the alternative interpretation that, inasmuch as longer particles are more readily phagocytosed, what is actually obs erved is the residual, smaller, nonpha gocyt osed chrysot ile.50 Thus, despite the detailed, in-depth informati on furnished by electron microscopy , no body of knowledge yet exists t hat permits the assigning of relative risk factors to fibers of differing lengths. In respect to asbestos bodies, it should be noted that "ferruginous bodies" produced in guinea pigs in response to other fibrous material, fine fibrous glass and ceramic aluminum silicate were identical in fine structure to that of asbestos bodies,51 thus rendering firm diagnostic decisions difficult in cases of multiexposures to different fibrogenic fibers in the electron and . light microscopic range . (6) Trace Metals . Harington and Roe 41 and later Cralley ~ !l_. 52 reported large amounts of nickel, chromium, manganese, and iron are intimately associated with certain forms of chrysotile. On the possibility that trAce metals may be associated with the induction of asbestos, cancer studies in animals were performed53 which supported the hypothesis that, in the induction of asbestos cancers, trace metals play an active cocarcinogenic role along with the exogenously derived carcinogen benzpyrene, while asbestos plays a passive role a.q a metal carrier. Correlation of Exposure and Effect Available information on the relationship of asbestos exposure and the risk of asbestosis and/or bronchogenic carcinoma is somewhat 111-17 extensive, indicating a strong association between the diseases and such exposure under a variety of condit1ons2,15,22,28 and evidence of dose-response relationship. Enterline and associates54 have recently demonstrated conv incing evidence for an exposure-response relationship between asbestos as measured in terms of million parts per cubic foot years (mppcfyr), and the risk of malignant and non-malignant respiratory diseas e, Specifically, the risk of respiratory cancer increases from 166.7 (standardized mortality ratio) at minimal exposures to 555.6, at accumulative exposures in excess of 750 mpPcfyr (Table XXX). Knox~ ~. 2 7 suggested that in one asbestos plant where environmental levels varied between 1 and 8 particles/cc) 5 )lill in length, the risk to bronchial carcinoma may have been largely eliminated, but that insufficient data were available t o estimate the extent of the risk that may remain. The different textile operations were fiberizing, carding, spinning, weaving, and plastering. When environmental samples collected by operation in 1961 and 1966 were summed, the averages were between 4 to 6 fibers/cc. Operational averages were from a low of 2.5 fibers/cc in weaving to a high of 6.5 fibers/cc in carding. In 1968 , Balzer and Cooper55 reported asbestosis among insulation workers exposed at levels not exceeding the time-weighted average of 5 mppcf. McDonald~ al. 56 reported in May 1971, on 129 primary thoracic neoplasms in the workers employed in Quebec chrysotile asbestos mines and mills out of a total of 9304 former employees; five of these cases were mesothelioma. The authors concluded that the additional data lll-18 supports evidence of other studies that even heavy exposure to asbestos in mining and milling carries only modest risk of contracting lung cancer and less still of contracting malignant mesothelioma. McDonald et al. suggest that any increased risk of respiratory cancer or pneumoconiosis at a dust-index below 200 would not be detectable and would still be in doubt below 400. At a dust index of 200 an employee could wcrk for 40 years at a dust concentration of 5 mppcf. The author assumes that the fiber content of the dust is about 10% and he states that this is equivalent to about 12 fibers / cc. c,, WrJ.gt1v' pointed out that others have noted the striking differences in the health experiences of workers in mines and mills as compared to other workers, specifically in comparison t o insulation operations, but that he felt the question was still un r esolved. In contrast to populations exposed to mixed environments, those engaged in the mining and milling of aRbestos fibers showed no augmented frequency of bronchogenic cancer. 2 Selikoff, 15 however, indicated that McDonald's "heavily exposed" group had 5 times as much hmg cancer as the "lightly exposed" workers. Furthermore, lung cancer among insulation workers was found to be about 7 times greater than expected compared to the general non-exposed population. 15 A non-exposed group was not reported by McDonald.56 Although it has been suggested that the risks associated with asbestos exposure may be less in mining than in industrial operations, additional study will be necessary to conf irm if such is true, based upon the comparison made by Selikoff.15 III-19 Consideration must be given to McDonald's analysis of levels of exposure of 12 fibers/cc. At this level , he assumes that some degree of asbestosis may occur. The mathematical assumption made to arrive at this environmental level leaves a great deal to question, even without attempting to relate this infonnation to the asbestos industry in general. Two primary considerations lack the evidence necessary to make general comparisons of these data with other reported work: the assumption as stated by McDonald 56 that the fiber content of the dust is 10%, and the method used to convert from mppcf to fibers/cc is net explained in the paper . Murphy ~ al. 58 found that asbestosis was 11 times more common among pipe coverers in new ship construction than among a control group. The asbestosis was first found after 13 years of exposure or about 60 mppcf years. The prevalence was 38i. after 20 years. The asbestosis was defined by the presence of at least three of the following signs: (1) basular rales in two or more sites, (2) clubbing of the fingers, (3) a vital capacity of less than 80% of the predicted, and (4) roentgenography consistent with moderately advanced, or advanced asbestosis, and (5) dyspnea on climbing one flight of st.airs . The environmental level was based upon samples collected in an impinger and all the results were time-weighted average exposures and these were averaged over several different operations. The highest average concentration was with hand-saw cutting at 10.0 mppcf and the lowest average was 0\8 mppcf when mixing mud. The average of all operations was 5.2 mppcf. One-hundred and one workers were Ill-20 in the exposed group with 94 used as controls mat ched for age, duration of employment and smoking habits. Both amosite and chrysotile were used in these operations while crocidolite was not. Murphy states that in his study no asbestosis was found for men exposed to 60 mppcf-years while 20% of those exposed for 75 to 100 mppcf-ye a rs were c onsidered to have asbestosis. Consideration must be given to averaging the timeweighted average values of the environmental samp l es over what seem to be several different sampling locations or oper ations. Were workers who were classified as suffering from asber-tos i e ~posed in the hand-saw cutting, or mixing mud, or both, and for what time interval? Answer to this question would have a major effect upon the relationship between the devel~pment of asbestosis and environmental levels, and the relation of these impinger counts to fibers/cc. In a recent unpublished paper, Williams, Baier, and Thomas compiled data from the Pennsylvania Department of Health files on exposure levels at various textile processing operations in two plants. The data included dust concentrations from 1930 through 1967 in one plant and from 1948 through 1968 in the second plant. Even though controlled exposures were for the most part below 5 mppcf and in many cases below the 1968 ACGIH Notice of Intended Change to 2 mppcf, 64 cases of asbestosis were reported from these two asbestos textile plants. The authors conclude that: "If asbestosis is to be prevented, airborne asbestos dust must be stringently controlled in the working environment. From these data a TLV of 3 mppcf would provide inadequate protection and the proposed 2 mppcf may not be substantiated." III-21 Thus, considerable evidence exists indicating that the prevention or reduction of the occurrence of asbestosis among workers requires that the concentration of asbestos fibers to which they are exposed be reduc ed. There is at this time, however, only scant correlation of epidemiological data with environmental exposure data upon which a definitive standard can be established. Champion 26 reported two cases of malignant mesothelioma in two men, 31 and 32 years old, following exposure to asbestos. In the first case, the only documented exposure of the patient was from his father, who at 68 years of age, had severe asbestosis following employment as a pipe lagger in Scotland. In this case, no special precautions were taken to protect the children from contact with the father's work clothing, which was washed at home. The man smoked about 20 cigarettes per day for sixteen years and had a brief history of breathlessness and other signs which could have been related to asbestos exposure. The second case involved a patient who had moved to Asbestos, Quebec, where he lived for the next 23 years. This patient had worked for 10 years as an asbestos prospector and had worked for a short period in open-pit mining. Seven years before his death in 1968, he moved away from the area and became a salesman in a department store. The patient smoked 20 to 30 cigarettes per day for 14 years. I n this case, it was believed that he was exposed only to chryso t ile and primarily in mining operations. Champion's two cases seem to support earlier data of family cases 15 with reasonably short and/or low levels of exposure. 111-22 Murphy ~ ~ 59 ptesented data concerning two cases of workers exposed to asbestos. One case on biopsy confirmed mesothelioma and the other case had extensive pleural calcification. Both workers had frequently sanded asphalt and vinyl tile fl oors prior to installation of new floor covering. A technique to simula te normal work practice was developed and levels of l. 2 and 1. 3 fibers I cc) 5 pm in length resulted. The authors noted that under other work conditions these values may be higher. In the case involving mesothelioma, the worker was 44 years old and had no other history of occupational exposure to asbestos, although he had worked in a shipyard in a "non-dusty" gyroscope repair area from 1945-1947. The repair area would practically have to be considered a clean room operation in view of the precision involved in gyroscopic instrument repairs. He had smoked one package of cigarettes a day between the ages of 17 and 30 and had worked from 1948-1967 as a floor tile installer. The second case involved a 61-year-old worker who had been a floor tile installer for the last 30 years and had smoked ane pack of cigarettes per day for the last 45 years. This second patient had no his tory of other asbestos expoAure different from the first; however, some question may be raised of a possible neighborhood exposure even if it only concerned going to work. The possibility of such exposure must be considered in view of the neighborhood case noted by Selikoff, 15 Tab.le XXIX. The possibility of the development of asbestos-related diseases in floor tile installation must be considered, and special attention must be given to this operation when considering the low levels of III-23 exposure that may be related to these two cases. If even in actual practice, levels were found to be 10 times those found by the investigators, it would substantiate the low levels of exposure recommended in this standard. The time interval for sanding as compared to tile installation must be small, and, if this is true, then, i n fact, any level found would be very low if based on a time-weighted average exposure. This increases the weight of consideration that mus t be given to this possibly exposed occupational group and the relationship of these low exposures to asbestos to the development of disease. Consideration must also be given related to the effect that may have resulted from exposure to other material in the floor tile. The level of, and effect of such material as asphalt and any decomposition products from sanding must be considered. Isolated clinical case reports are difficult to interpret in terms of dose-time response relationship and can only be used to indicate other possible problem areas and to highlight what may prove to be practicable areas for further study. III-24 IV. ENVIRONMENTAL DATA The use of asbestos has changP.d with the addition of new products an~ with changes in the industrial processes. These changes and a growing awareness of the health effects f rom exposure of the worker to asbestos have resulted in a changing work environment within the asbestos industry, The lack of environmental data for previous years and the r.hanges in technology used to collect samples, now and in the past, have resulted in the availability of comparable environmental data for only the last few years. Thus, the scant data and the long latent period for the development of bronchogenic can cer and mesothelioma do not permit the establishment of the dose-re sponse relationship at this time. However, as has been indicated, the development of the diseases has been proven in workers exposed to as bestos and environmental data does exist for the last several years, Table XIV shows the average concen t ration of asbestos fibers to which a number of insulation workers we r e exposed in 1969. The results shown are not timeweighted averages, but are averages of concentrations found for individual exposures during the time samples were collected (usually 15, 30, or 60 minutes). Although the average concentrations are reasonably low, vith the exception of spraying, indivi~ual exposures varied from 0 to 100 fibers/cc. The latter occurred during a 60-minute period while a workm.an sprayed asbestos fiber oo a turbine. McClure60 summarized results of a preliminary survey conducted by the U. s. Department of Labor during the period July, 1969, to January, 1970, at nine private shipyards as follows: 37 of 74 samples IV-1 collected auring various operation.a of preparing and applying insulation were above 2 fibers/cc (50%) and 19 of 74 were about 12 fibers/cc (26%). These were not time-weighted average exposures, but represented average fiber concentrations during the sampling pe r iod. Furthermore, none of these samples represented workers' exposures while tearing out old insulation and lagging--an operation that has been previously found to produce more dust than the application of the insulation. A summary of some of the environmental data collected by NIOSH is presented in Table I through XII. Tile environmental data presented in this document represent only that collected in the last few years and reported in fibers/cc)5 ,m as counted by phase contrast light llicroscopy, As pointed out by Ayer.!:,!. a1,6l, "It is obviously impossible to give any single ratio that would accurately represent all processes at all times in each plant." As a result, 11 t tle correlation, if any, can be made between early data (collected with an impinger where settled particles were counted) with current data (collected with a personal sampler and counted under a microscope equipped with a 16 llDI 101 objective). These data represent only the levels found during the time the samples were actually being taken, The sampling times were usually between 15 minutes to one hour, and should not be considered as timeweighted average exposures even though credence could be given to this approach due to the large nUD1ber of samples collected. Levels of exposure in the aanufacture of asbestos are given in Table I through XII. In a total of 7 asbestos cement pipe plants, a range of individual samples waa fra11 13.4 in coupling finishing. to levels too low to coWlt in pipe fonning, curing, pipe finishing. IV-2 coupliog finishing, It should slao packiog and be noted in miscellaneous operations (Table Table I that when consideration I). 1a given to feasibility of engineering control, in coupling finishing, the individual highest sample was 13.4 and the lowest and second lowest samples were zero. Warehousing and mixing (6.3 fibera/cc>5 Jm) and packing (6.1 fibers/cc>5)1111) were the highest means by operation (Table II), and the lows were both 0.4 fibers/cc).5 JJZI These data indicate the possibility of cootrolling these operations to below the proposed standards. These wide ranges of individual s&JJ1ples and means by operation were also shO\ill cement shingle, in asbestos friction plants (Tables III and IV), millboard, and gasket operations (Tables V and VI), insulatioo (Tables IX and X), and from asbestos paper, packing and asphalt In products (Tables VII and VIII) . textile operations, while the individual low and second lowest concentrations were, in all cases, below 1.0 fiber/cc (except fiber pfsliporbe1veDpersleslrti/anctggciroo(oi3un,.p7,1f i.fa4bileblfreirobpaper/eercrspca/a)tc,ircoa)ant,insodntehxtew(c7emi.sp4ettai nnffsgiibnbei(ys3rhs.o2/i ncpcgef i)rb,aetexicrcoasenr/esdcdicened)xg.c2e(.e6l0do. e1fdtihfb2ieeb.r0esser/ccso/ccn. dc ) , These values, when individual sau;plea considered with the (143.9 fibers/cc in highest carding means and and 123.2 highest in weaving), indicate that present methods of control practiced in the textile inJustry are not adequate for the standard proposed. This is probably true in insulat ion operatioos aa well. though levels were below the level of 2.0 fibere/cc/5.)Jll, the Even individual s&lllples aod operational means were high. IV-3 The individual sample high (Table IX) was 208.4 in finishing and 186.9 fibers/cc in mixing. Table X:XV shows that in at least one insulation plant, 100 percent of all samples t aken were less than or equal to 2 fibers/cc>5 pm, and in one other, all but the mixing operations met the 5 fibers/cc>5 pm value. In textiles 1 under present operating conditions, none of the plants met the 2 fibers/ cc)5 pm criteria {Table XXV). This does not iiaply that industry could not meet the proposed standard of a time-weighted average exposure of 2.0 fibers/cc>5 JllD but only that it is not meeting it at the present in the insulation and textile plants, and it probably could meet the standard if given time to clean-up the plant operations. Secular trenda indicate that there is a wide variation between a few samples taken over large intervals of tille. The evaluation of these trends, if indeed they are trends, vould be open to question, however, it does point out that much can be done in the improvement I of plabt operations, It is not reasonable to associate these difference with ch11nges in field sampling methods, coun ting techniques, or locations of sampling devices when similar trends are not apparent in cement pipe {Table XV), friction (Table XVI), or shingle , aillboard and gaskt operations (Table XVII). Variation in trends in insulation and textile plants (Tables XIX to XX!) indicate stable plants in ecxae areas and not in others. The comparatively low values in textiles is somewhat surprising. At most of the operations in the well-controlled plants, it is possible to ~eet the proposed standard with only small changes in engineering practices (Table XII). TI\ia i s also true to a leaser degTee IV-4 in friction operations (Table XXIII), &Dd ahingle, aillboard, and gaak.et operations (Table XXIV), and true in only a few operations in textiles and insulation operations (Tables XXV-XXVI). It must be noted that in asbestos plants having the same operations, some have been able to meet the proposed standard, while others have exhibited environmental values at higher level~, which suggests the need for engineering control - not the lack of engineering feasibility to meet the standard. It will not be easy to control exposure in the insulation and textile industries, where higher levels of asbes tosis, lung cancer, and aeeothelioma are known to occur. There is a high pri ority requirement to protect the workers in these industries to assure that excessive aabeatosia, lwig cancer, and meaothelioma will not continue and, at the same time ~ give the vorker the type of protection that is required at once. Tabla XIII givee an indication of the dramatic reduction in time-weighted average exposures that could be acccaplished if peak or ceiling exposures were elilllinated. In this case, reducing the peaks in insulation operations to the ceilina of 10 fibers/cc reduced the time-weighted average to near 2 fibers/cc. IV-5 V. DEVELOPMENT OF STANDARD Various criteria have been used for categorizing the dustiness of the environment. Recent developments have made it clear that a method utilizing the capture and direct estimation of fibers of asbestos should be utilized for environmental measurement of exposure t o asbestos. I n the past, in the United States, asbestos fibers were measured by the impinger method which included counting particles as well as asbestos f ibers. The question still exists as to whether or not different varieties of asbestos fibers may have varying biological effects. This will not be answered until more definitive information is available on the specific etiological agent(s) and mechanisms of injury involved . The consumption of asbestos in this country is overwhelmingly in the form of chrysotile . Where other forms of asbestos are used, such as crocidolite and amosite, they are often mixed with chrysotile and are encountered alone, mainly in research and specialty situations . It would be extremely difficult on the basis of current information on biological effects and industrial practices to establish and administer separate standards for different types of asbestos. The question also arises on the validity of basing standards on the number of respirable fibers in the air greater than 5 micrometers in length. It is fully realized that the fiber-size spectrum of respirable asbestos fibers in any particular industrial environmnt will range from that of bundles of fibrils in the upper respirable size to those of the individual fibrils in the sub-micron size. The type and grade of fibers, nature of processing, and con trols in existence will greatly V-1 influence the f iber-size spectrum (fiber length and diameter) in any given environment. The problem is further complicated by the lack of definitive information on the biologic response to fibers of different sizes . It is known, however, that the longer fibers show a dose-response relation to asbestosis, and may have a different behavior and degree of response than the shorter size fibers which may, in the lower and sub- micron range, tend to resemble more the physical behavior of non-fibrous respirable particulates. Since it would not be feasible to have a standard on the total respirable fibers which wo uld necessitate the routine use of expensive and time-consuming techniques including electron microscopy, an index of exposure must be selected which, as nearly as possible, relates to the predominant biologic activity and dose-response of the size spectrum of fibers most co11DDonly encountered. It is assumed for the present that the factor of safety associated with the standard will allow for differences in the size spectrum of respirable fibers that may be encountered. The British, in evaluating respirable chryso tile fiber expos~res in relation to the ongoing epidemiologic studies in the textile industry and for the basis of a standard for chrysotile, established as an index of 62 exposure, fibers greater than 5 micrometers in length. A substantial amount of information on the biologic effects of asbestos has, and is, being obtained using this parameter of exposure measurement. A review of the research in Britain, with concurrence on the rationale involved, made it prudent that we use the same definition of i nd ex-of-exposure on which to base criteria for standards. These criteria should be re-evaluated when, (1) more definitive information on the biologic response of asbestos including the agent(a) and dose-response data on different lengths of fiber is v~2 available, (2) the spectrum of fiber lengths encountered in industry by types of asbestos and operations is ascer tained, and (3) more precise epidemiologic data are developed. To prevent fibrosis and excessive r a tes of neoplasia, such as mesothelioma, respiratory cancer, and gastrointestinal cancer, a standard for asbestos duet should be based on a concept of dose-response that includes not only the factor of fiber count times years of exposure but also that for total asbestos dust fibers retained over a number of years. Thus, the effect after several decades of a one-time acute dose of limited duration which overwhelms the clearing mechanism, and is retained in the lungs, may be as harmful as the cumulative effect of lower daily doses of exposure over many years of work. V-3 BritpewnawececNeasanohoxisvorfmepsntnotiraTodeicmreuftcesheerioeecloennvcnoderfcotadeusfreensnPfatidbcnolhprrtoieeeiesreemobfnsnvtrydntitmi3oaoerstc9sDoadssuutr.tbwsafrebipteoenoeieeeSrcstrdTnrshxettashssoaaaftoreeunnsiosdynnelnbidosexsd1eatffe;ceoso0reetpdtrurx(beolysmnpdauas5edcoelpntao.dsmdptern6onscusd3upn5tfsmprw)ltt,otycimeohonflriep.dlonsripcec1uiencotx9osHegtfn3mnh,row8ocmceeawebfeesxifenulntnsoplvtettie-tolhverrmxdlasreaeoo,tutastnwiibirreeloloyoekiyexnnnnehplsgtdtsatyiohohdnsefbacrdurfaeaeboirusilssvemeemobsteeseuwtespndrd0siyoopynt.o2ecuo0egfm.ocbrs5eousfpttrpffoorldmnuorn5ut5eeylpse44sudepmct1.mdcc.h9hfiaawonlemAsdlmcmiaseiqoohsospbpruonnpelewieowceo,eyftnhs.dheiesearsne ffiioaassnvtansttchesualbtetyndehtyTdistehl2eethhiaseodmeaarefsdrtotisshhttrt.taaee3ruede3tsxmdxi3sttyoaobthiirbenoloelbeelfselynidtstmhawhDhianvneeiorndalderlloke5ssu24sepw,t0es1raeaesostryfneeanoewmbdtl~ariayaporssstlaneoh6!s.3d6y.ab!2fe.toe.weuF1srspe.uhtoroyarmsn.etdsethou-.aelredudriemrsmunim"pesat5ilhdaotvtonaeroymdeenhdie,xpdadoppd1adtcno5bahafwlslsetyeuyaomrel.raaoelokayvinenrmeuedsgTbrn.haieoltaegtefaiserslTteatsihg1uahbo0uatgenethsrehsytd,ofateerooesntsdafuuhrrcrefrstthdiehe,vpafcenaetlioasaatsrgneansydntattteiihsrzvaeeeresdly available." The American (ACGIH) Threshold Conference of Governmental Industrial Hygientists' Limit Value (TLV) for asbestos dust was 5 mppcf V-4 from 1946 to 1970. This limit was baRed on the study by Dreessen et al . 63 and subsequent investigations by others . In 1968 and 1969, ACGIH published notices of intended changes to lower the TLV te 12 fibers/ml .> 5 ym in length or 2 mppcf and they published in 1970 and 1971 a still iower limit of 5 fibers/ml 75 pm in length as a notice of proposed intended change. The conversion of dat a from mppcf to fibers/ml in all asbestos operations can only be done with considerable risk to the validity 0f th>'. rei; u l ts . Lyn ch !.!:_ al_. 64 point.ed out in 1970 the need for such conversion data and that the data repor t ed in 196561 of the 12 fiber/ml equivalent to 2 mppcf relationship was obtained in textile mills and should not be applied to other produc t areas. Estimates of risk of disease in other product areas should be based on fiber counts since this method yields a more direct estimate of airborne asbestos concentration. In 1968, the Committee on Hygienic Standards of the British Occupa- tional Hygiene Society (BOHS) after rev iewing medical evidence, results of studies made by the asbestos industry in the United Kingdom, and epidemiological data from the United States, published Hygienic Standards 62 for Chrysotile Asbestos Dust. It stated: "l. As long as there is any airb orne chrysotile dust in the work environment there may be some small risk to health. Nevertheless, it should be realized that exposure up to certain limits can be tolerated for a lifetime without incurring undue risks. "2. The committee believes that a proper and reasonable objective would be to reduce the risk of contracting asbestosis to 1 percent of those who have a lifetlme's ~xposure to the dust. By 'asbestosis' V-5 this committee means the earliest demonstrable effects on the lungs due to asbestos. "It is probable that the risk of being affected to the extent of having such early clinical signs will be less than 1 percent for an accumulated exposure of 100 fiber years per cm3 or 2 fibers/cm 3 for 50 years, 4 fibers per cm3 for 25 years or 10 fibers per cm3 for 10 years. "3. It is recommended that exposures which lie in certain ranges of dustiness be designated by categories according to the following scheme: DUST CATEGORY CONCENTRATION AVERAGED 3 MJNTHS (FIBERS/cm 30)VER Negligible Low Medium High 0-0.4 0.5-1.9 2.0-10.0 Over 10.0 "4. The levels are expressed in terms of the number of fibers per cm3 greater than 5 pm in length as determined with the standard membrane filter method. Any other method can be used provided it is accompanied by appropriate evidence relating its results to those which would have been obtained with the standard membrane filter method. "5. When it is necessary to work intermittently in a 1high dust' area an approved mask should be worn, provided that the concentration is no more than 50 fibers per 3 cm a higher standard of respiratory protection should be provided such as a.pressure-fed breathing apparatus. V-6 "Additional Recommendations "l. It is recomnended that where practicable an up-to-date employment record card be kept of every person which indicates, every calendar quarter, the category or categories in which he or she has been employed and in which he or she is recommended to work. "2 . All employees exposed to risk should be medically examined before employment. Periodic examinations should be made thereafter, annually. ''Notes: "These hygienic standards are subject to review in the light of new evidence and improved methods of measurement . "The standards are, in our opinion, the best that can be drawn from the existing data. These data are scan ty and based on factory experience of continuous exposure during working hours. Due caution should be exercised in applying these standards t o other patterns of exposure. far as possible the dust exposures have been estimated conservatively As and, in particular, in the period 1933- 1950 the average hours of work were substantially greater than 40 per week. "It is hoped to supplement the existing data in due course, when the standards will, if necessary, be modi f ied. These standards will be formally reviewed in three years." In an unpublished paper, Williams, Baier, and Thomas compiled data from the Pennsylvania Department of Health files on exposure levels at *As of 1/6/72 revised. Per the Asbestosis their standards as effe telephone conversation Research Council. ctive with in Dr. May S. 1970 Holme had not been s, Secretary to V- 7 various textile processing operations in two plants. Their data included dust concentrations from 1930 through 1967 in one plant and from 1948 through 1968 in the second plant. Even though controlled exposures were, for the most part, below 5 mppcf and in many cases below the 1968 ACGIH Notice of Intended Change to 2 mppcf, 64 cases of asbestosis were reported from these two asbestos textile plants. The authors conclude that: "If asbestosis is to be prevented, airborne asbestos dust must be stringently controlled in the working environment. From these data a TLV of 3 mppcf would provide inadequate protection and the proposed 2 mppcf may not be substantiated." Gee and Bouhuys, 65 in December, 1971, pointed out that on the basis of 11reasonable probability," decisions must be made to control exposure to asbestos rather than from a precise definition of dose-response relationship, and "the present threshold limit value for asbestos should be lowered far below some recent proposal. 11 v-8 U. S. Emergency Standard The present emergency standard for exposure to asbestos dust (29 CFR 1910.93a) published in the Federal Register, Vol. 36, No. 234, page 23207, December 7, 1971) is as follows: "ael4mcmuTexs0opahbnc0iyneeeg-lt4telsbotr5i8dthealo0-,is5hXs5tptoeaheudfmsirroirulmbuladeburetgetiiusmtrntmtetstie,iiorefndnmi-pncawweiaouatnerihptnteoiiigocmdntt8hhnoo.-tibheleye(aodlm4Cxiutlcptroahimoelvnteoedteeicydalaremrellaynie1egm.gstm0o"rereafbaefttraraeai1ieintorb5reebneeromsorxfsbrpitianjnholbepeuatsoceentevetrdcriesov5msmne5imh)cnielaeftihlcpinlaibolrhntlodreainnarsthotsaseeoittoruip,nrnefroofr The 1971 ACGIH tentative threshold limit value is 5 fibers/ml ) 5 pm in length. Both are higher than the British standard of 2 fibers/cc by at least a factor of 1.5 times. V-9 Basis for RecoJilmended Standard The number of studies that have collected both environmental and medical data and with a significant number of exposed workers is not sufficient to establish a meaningful standard based upon firm scientific data. The requirement to protect the worker exposed to asbestos is defined in a number of studies outlined in thi s document. The general recognition of the increasing number of cases of asbestosis, bronchogenic cancer, and mesothelioma indicates the urgent need to develop a standard at the present time. NlOSH recognizes that these data are fragmentary and, as a result, a safety factor must be included in any standard considered. On this basis the research that did include both environmental and medical data, or where a standard or limit had been proposed, was given a careful and detailed study to determine its particular contribution to the development of a national standard. 66 The development of a standard for asbestos dust in Great Britain and the evaluation made by the British Occupational Hygiene Society 62,66 (BOHS) Sub-committee on Hygiene Standards for Asbestos, which considered data to reduce the risk of asbestosis, was given great weight in the development of this asbestos standard. 'nle BOHS fitted the data available to a dose-response curve and the conclusion was drawn that an accumulated exposure of 100 fiber-years/cm3 would reduce early clinical signs to less than 1%. This would be 2 fiber s /cm3 for 50 years of exposure or 4 fibers/cm3 for 25 years. 67 According to Roach, "The British Occupational Hygiene Society Standards Sub-committee on Asbestos expressed the view that a proper and reasonable objective would be to reduce exposures to below this level and thereby reduce the riek of V-10 contracting asbestosis to less than 1% of those who have a lifetime exposure to the duet. For such workers, who may possibly work for 50 years, the long-term average concentration to which they are exposed would need to be lees than 2 f1bere/cm3 . For others, who will be exposed to asbestos dust in air for long-term average concentration need not be exposure will amount to less than 100 fiber- s s y horter pe o low, as ears/cm3, rio lo 11 ds ng , th as e t h e i r It is recognized that the British standard is based upon data not as precise as desired, but it does offer a mechanism for com- phawifbaanrhasrosiistmacsuebnhoddenleyadnuswtipoboforfifeentecsh2o2rt7b1o9e1ta0snhDfsiteDambtleeeewAnnxrdCrosetaGre/diklcIm.lHeemepersl3TTomL.ahyhVneieadlddlTaB.nXhfbrdeo-ierrtTearaihnisyf1seht0keece-xrhsyenptaexvoatnapihnsgrreordosedesanseur.mowdrryeeeernwIlenraotaaersnelsltgashpdettoiriirusmfioembnatuseaststtcerhuewidoidlepnynyetocs,noebwcnba1hhstae9araers3avneda3tegl-ideuo1vepr9navoa6srnel6ieletosodped were considered the key symptom since all workers exhibiting X-ray changes also exhibited basal rales. In reviewing the values on the basis of the 100 fiber-yeare/cm3 pcUfTiroo.sohmrepSpbod.EaasirmesSfiedsfetdoeragbnrnueyesdnpnacotccyrhnaedens.Uan.BbienErSeiax.mtctpihhasSodehtsesautwnHabrdoeneyartdgkwrtaidiieenrmndegieensiloStsibhfftaaeensn3toei0dBrmdamryreiudaetplasiioosrzfnhCsedotttShmhotetemao5niaAtd1vtCfae0eGire0brdI,aHefgtraiehTsbnLe/deaVmrsf-tblwohy)elehels5oiatcEworhusmsmi,newtgriiognnoernaktlccueeycnrro.ngu,tnht68 V-11 and the British, 50 years of exposure a t 2 fibers/cm3 > 5 um in length. ln sunnnary: British u. S . Emergency ACGIH Fiberyrs/cc 2 fibers/cc 100 5 fibers/ml 150 The validity of this type of comparison has already been questioned in this document, i.e., the "K" factor used to change ACGIH impinger data to fiber counts. 61,64 However, on this basis, data suggest that the ACGIH value is higher than the British value. In addition to consideration of the British data, the comparison of British and ACGIH data suggests that the 30-year exposure value for a U. S. Standard should be about 3 fibers/cc 5 m in length in order to assure that less than li. of t he workers exposed are at risk of developing the earliest clinical signs of asbestosis. However, additional consideration must be given to the concepts of carcinogenesis as they relate to the determination of a standard for asbestos exposure. Any carcinogen (initiator) must be assumed, until otherwise proven, to have discrete, dose-dependent, irreversible and additive effects to cells that are transmissible to the cell progeny. Thus, initiation of malignancy following single small exposures to asbestos is possible, but of a low probability. With frequent or chronic exposure and a low dose-rate, the prob~bility of initiation of malignancy is increased. Yet, even under optimal conditions of cell proliferation (in the presence of promoters) these malignant V-12 transformations do not lead to instantaneous cancer, but remain insidious for a number of years (latent). In protracted exposure, some of the t otal accumulated exposure is "wasted" (or irrelevant) as far as the initiator of cancer is concerned. Exposures in excess of the minimal initiation dose conceivably may shorten the latent period to some extent by substituting for other contributing factors that would have eventually been effectual in converting the latent tumor into a frank malignancy. Analytic methods used in the epidemiology of asbestos-induced cancers are unable to discriminate between the initiating dose and subsequent (wasted) exposure . Consideration must also be given to the concept that an inverse relationship exists between dose-rate and the latent period. As the dose-rate becomes progressively lower, the latent period may approach or exceed the life span of exposed individuals. Adherence to these concepts would argue toward reducing asbestos exposure substantially below those levels currently demonstrated to be associated with the disease. Such a course of action is consistent with the Surgeon General's ad hoc CoDDDittee on Evaluation of Low Levels of Environmental Chemical Carcinogens statement that, "for carcinogenic agents, a safe level for man cannot be established by application of our present knowledge." Work practices in industries should be encouraged to develop work practice standards by the consensus method so that the lowest feasible environmental levels can be obtained . 1be following work practice standards are included in the emergency standaTd for asbestos and are included in the recommended standard: V-13 (a) Asbestos cement, mortar, coatings, grout, and plaster shall be mixed in closed bags or other containers. (b) Asbestos waste and scrap shall be collected and disposed of in sealed bags or other containers. (c) All cleanup of asbestos dust shall be performed by vacuum cleaners or by wet cleaning methods. No dry sweeping shall be performed. Tile need in industry for a proper precautionary label for asbestos and for other hazardous materials associated with the mining, production, and use of chemical compounds has existed for a number of years. Tile development of a labeling system for use as an occupational hazard warning system overlaps into so many other labeling areas, e.g., transportation of chemicals, fire fighting, use by the military, etc., that it would be necessary either to develop a separate aystem for use in relation to occupational exposures only, or to combine all the present systetne into one. The addition of one more labeling system compounds the multi- labeling requirement presently imposed on industry and creates one more labeling system the worker must recognize. Combining all systems into one requires the coordination of many governmental, professional, trade, manufacturing, and international and local organizations. Time required to accomplish this task is prohibitive in relation to the requirement for the immediate development of an occupational health 1tandard for asbestos. As a result, NlOSH recommends as an interim system the adoption, with modification, of the system for the Identification of the Fire Hazards of Materials of the National Fire Protection Association and the Guide to Precautionary Labeling of V- 14 H&zardoue Chemicals of th Manufacturina Chem1et ~ociation. It i recognized that thi eyete~ may not be the mot appropriate eyetem and may require additional development to permit the worker. hiiuelf, to use it to identify the hazard to which he is expo1ed and to learn the nec11aary precautiona to aeeure him aaf e working conditions. (See Appendix II for the detail and modification of the labelina eyatem). V-15 Summary of the Basis for the Recommended Standard The recommendation for an environmental standard for asbestos is based upon health considerations and limited engineering feasibility data. The overriding considerations are the health effects. Evidence indicates that past and current standards for fiber concentrations in the working places where asbestos fibers occur, though undoubtedly contributing to reduction of the severity and frequency of asbestosis, have not provided complete protec t ion from exposure to asbestos, necessitating development of a new s tandard. Consideration was given to previous reports and studies, recent data, and the present "state-of-the-art." It is recognized that additional data would be desirable to support an asbestos standard, but because of immediate need for worker protection, it is necessary to make a recommendation based on available studies and data. The following constraints in applicability of research data were considered in the development of the recoI11111endations: (a) Few epidemiological studies or clinical reports with supporting environmental data are available in the exposure range that must be considered. (b) Environmental data on practically all studies were collected only over the last few years and/or they were collected by other techniques and expressen in terms other than fibers/cc. (c) The environmental samples were expressly collected in many cases for control purposes rather than for research and, as a result, meaningful evaluations cannot be made. V-16 (d) There is a lack of data to define with any degree of precision the threshold of development of neoplasms resulting from exposure to asbestos and the relationship of the latent period between exposure and development of neoplasms. The standard recommended in this document is similar to the standard adopted by Her Majesty's Factory Inspectorate in 196966 (still in effect as of December 29, 1971), and more stringent than the recent U. S. Emergency Standard. It is felt to be feasible technologically for the control of the exposure to the worker and ef fective biologically for protection of the worker against asbestos-induced diseases. Considerations of carcinogenesis indicated the need for a measure of prudence. As a result of this rationale, a factor was added to reduce the time-weighted average exposure to 2.0 fibers/cc> 5 um. A ceiling value of 10.0 fibers/cc> 5 um that was not to be exceeded was included to reduce the possibility of the short-term heavy exposures to asbestos that have been reported to cause mesothelioma. In addition, this should reduce the likelihood of diseas es (malignant and non-malignant) resulting from exposures in excess of 30 years or with very long latent periods. V-17 VI. COMPATIBILITY WITH EMISSION STANDARDS The propos.ed .. ruational emission standard for asbestos was published in the Federal Register, Vol. 36, No. 235, pages 2342-2343 (40 CFR 61.2061.24) by the Environmental Protection Agen cy. The emission standard will be applicable to asbestos mines, mills ; building structures, or facilities within which manufacturing or fabricating operations involving the use of commercial asbestos; buildings or structures which have been or will be constructed or modified using asbestos insulation products; roadway facilities which would be surfaced or resurfaced using asbesto tailings . Tiie standards are baaed upon infonnation derived from many sources, including health effect levels, v.e teorology, technical analysis of control capability, and consideration of economic illpact. The overriding considerations are health effects. These s tandards are based upon specific operations and physical conditions and are limited in general to emissions to the atmosphere. 1. Emissions shall not exceed those which would be emitted froa operations if proper engineering control had been installed (i.e. fabric filter, cyclone gas cleaning devices). 2. Visible emissions of particulate 3. Spray ing of asbestos 4. Use of asbestos for surfacing or resurfacing of roads. The use of procedural standards and visible emissions as the basie for evaluation for ca:npliance with the staodard are designed to ainiuize emisaion to the atmosphere. EPA detenained that there VI-1 is no suitable technique for sampling and analysis of asbestos in ambient air or emission gases. Tilis determination was made as only limited information had been developed from measuring fibers in com1nmity air. The use of high volume saaple rs for collection of s&Dples and counting by light microscopic techniques ei.Jlilar to industrial hygiene methods has shown only &11all numbers of fibers in urb~ areaa. 69 It was felt that these values were lov when compared to occupational health experience and values to few too use vith confidence.69 As a result there is no direct comparison possible between the proposed national emission standards for asbestos and the reca11111ended criteria for occupational exposure except t o say that the levels of exposure to the general public on a 24-hour day, 7 days a week, basis would be lover, as would be expected, than occupational standards baaed on an 8-hour day, 40-hour work week. Tile Illinois Pollution Control Board on November 30, 1971?0 published a notice of proposed final draft of emission standards for asbestos that can be more easily related to the recommended occupational standard than those proposed by EPA. Illinois includes a provision that, "After June 30, 1972, a factory, plant or enterprise which engag~ in the processing or manufacturing of any asbestos-containing product shall discharge no visible emission of particulate matter frOUJ such manufacturing or processing into the ambient air and shall ea.it no concentrations of asbestos fiber in excess of 2 fibers per cubic centimeter of air." Vl-2 The method of counting the asbestos fibers is that proposed by Edwards ~.!.!. 71 and similar to the technique proposed in Appendix I of this report. Thie proposed Illinois standar d places a ceiling value of 2 fibers/cc on emissions from processing on m.anufacturing of asbestos containing products. In the explanation of the revision of the proposed Illinois regulation they state: "IV. Part V, controlling manufacturing sources, is changed to require an emission standard of 2 fibers per cubic centimeter and no visible emissions. While some testimony indicated the difficulty in measuring compliance vith a DUlll~rical emission standard, overall the evidence establishes both the need (protection against the great proportion of invisible fiber) and the ease of iaeasureaeut of such a criterion. A "no visible emission" standard ha9 been added to the numerical standard to simplify enforcemeat against exceptionally dirty emission sources. A grace period, uritil June 30, 1972, has been added to permit acquisition of the necessary control equipment to attain the emission standard." This air quality standard is, as it should be, more restrictive that an occupational standard due to differences in exposure time. Thia proposed occupational atandard would seem to be compatible vith the proposed emission standard and each should compleaent the other in the control of asbestos exposure. Vl-3 vn. REFERENCES l. Hendry, N. w. The Geology, Occurrences, and Major U of Aabeatoa. Ann. N. Y. Acad. Sci,, Vol. 132, Art, 1, pp. 1-766-1965. 2. Wright, G. D. Asbestos and Health in 1969. Am. Rev. Reap. Dia., Vol. 11, pp. 467-479, 1969. 3. Asbestos position paper, DREW, USPHS, BOSH, 1969. 4. Report of the Departmental COlllllittee OD Compensation for Industrial Diseases. C. D. 3495, 3496. HMSO~ 1970. 5. Cooke, W. E. Pul.Donary Allbestoais. Brit. Med., Vol. 2, pp. 1024-1025, 1927. 6. McDonald, s. Histology of Pulmonary Asbestosis, Brit. Med, J,, Vol, 2, PP 1025-1026, 1927. 7. Hoffman, F. L. Mortality from Respiratory Diseases in Dusty Trades (Inorganic Dust). Bull. u. s., Bur, Labor Statistics, No. 231, PP 176-180, 1918. 8. Pancoaat, H.K., T. G. Miller, and H. R. K. Landis. A RDllntgenologic Study of the Effect of Duet Inhalation Upon the Lungs. Trans. Assoc. AD. Physic,, Vol. 32, pp. 97-108, 19 17, 9. Milla, R. G. Pulmonary Asbestosis; Report of a Case. Minnesota Med., Vol, 13, PP 495-499, 1930. 10. Lynch, K. M., and w. A. Smith. Aabestosi1 Bodies in Sputum and Lung. J, Am. 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Stumphius, J, Epidemiology of Mesothelioma on Walcheren Island. Brit. J. Ind. Med., Vol. 28, pp. 59-66, 1971. 32. McEven, J., A. Finlayson, A. Mair, and A. A. M. Gibson. Mesothelioma in Scotland. Brit. Med. J., Vol. 4, pp. 575-578, 1970. 33 . Stumphius, J., and P. B. Meyer. Asbestos Bodies and Mesothelioma. Ano. Occup. Hyg., Vol . 11, pp. 283-293, 1968. 34. Gardner, L. U., and D. E. Cummings. Studies on Experimental Pneumokoniosis VI Inhalation of Asbes tos bust. J. Ind. Hyg., Vol. 13, pp. 65-81, 97-114, 1931. 35. Vorwald, A. J., T. M. Durkan, and P. C. Pratt. Experimental Studies of Asbestos. A. M.A. Arch. Ind. Hy g . Occup. Med., Vol. 3, pp. 1-43, 1951. 36. Wagner, J.C., and G. Berry. Mesothe liomas in Rats Following Inoculation with Asbestos. Brit. J, Cancer, Vol. 23, pp. 567-581, 1969. 37. Stanton, M. F., R. Blackwell, and E. Miller . Experimental Pulmonary Carcinogenesis with Asbestos. Am . I nd. Hyg. Assoc. J., Vol . 30, pp. 236-244, 1969. 38. Gross, P., R. T. P. deTreville, and M. N. Haller. Experimental Asbestosis-- The Development of Lung Cancer in Rats with Pulmonary Deposits of Chrysotile Asbestos Dust . Arch. Envir. Hlth., Vol. 15, pp. 343-355, 1967. 39. Smith, W. E. et al. Comparison of Bi ologic Responses to Harsh and Soft Chrysotile Asbestos. Submitted to Arch. Envir. Hlth. for publication. 40. Wagner, J. c. Asbestosis in Experimental Animals. Brit. J. Ind. Med., Vol. 20, pp. 1-12, 1963 . 41. Harington, J. s., and F. J.C. Roe. Studies of Carcinogenesis of Asbestos Fibers and Their Natural Oi l s. Ann. N. Y. Acad. Sci., Vol. 132, Art. 1, pp. 439-450, 1965. 42. Webster, I. Asbestosis in Non-experi mental Animals in S. Africa. Nature, Vol. 197, p. 506, 1963. 43. Schuster, N. H. Pulmonary Asbestosis in a Dog. J. Path. Bact . Vol. 34, pp. 751-757, 1931. 44. Gardner, L. U. Chrysotile Asbestos as an Indicator of Subtile Differences in Animal Tissues. AJIJ. Rev. Tuberc., Vol . 45, pp 762-766, 1941. VII-3 45. King. E. J., J. and of Asbestos W. Clegg, and V. M. and Aluminum on the Rae. Lungs The Effect of Asbestos, of Rabbits. Thorax, Vol. 1, pp. 188-197, 1945. 46. AASmlsubimtehis,ntaoJ.s.isMTih.n,orRIa.xa,tDsV.. oPlT.. hWe6,oEopftpfoen. c, 1t a2no2df-1EP3.6a,rJt.1ic9Kl5e1in. Sg.i Experimental ze and of Added 47. Parraz!, E., B. Pernis, G. on "in vino" Cytotoxicity C. of Secchi, and E. C. Vigliani. Asbestos Dusts. Med. Lav., Studies Vol. 59, pp. 561-576, 1968. 48. Secchi, G. S., and A. Rezzonico. Hemolytic Activity of Asbestos Dusts. Med. Lav., Vol. 59, pp. 1-5, 1968. 49. Suzuki, Y. and J. Churg. Body. Arch. Path., Vol. Structure and 55, pp. 79-91, Development 1969. of the Asbestos 50. Stokinger, H. E. Lobar Insoluble Particulates. Deposition and Retention of Inhaled Arch. Ind. Hyg. Occup. Med., Vol. 4, pp. 346-353, 1951. 51. Davis, J.M. G., P. Gross, and Bodies" in Guinea Pigs. Arch. R. T. P. deTreville. "Ferruginous Path., Vol. 89, pp. 364-373, 1970. 52. Cralley, L. J., R. in the Manufacture Assoc. J., Vol. 28, G. Keenan, and J. R. of Asbestos Textile pp. 452-461, 1967. Lynch. Products. Exposures Am. Ind. to Metals Hyg. 53. Dixon, J. R., D. B. Lowe, Stokinger . Role of Trace Asbestos Cancers. Cancer D. E. Richards, L. Metals in Chemical Res., Vol. 30, pp. J. Cralley, and H. Carcinogenesis: 1068-1074, 1970. E. 54. Enterline, P., P. Decoufle, and V. Dose-Response Relationship Between Henderson. A Study of Asbestos Dust and Lung the Cancer. Unpublished Manuscript. 55. Balzer, J. L., and Workers. Am. Ind. W. C. Hyg. Cooper. Assoc. J ., The Work Vol. 29, Environment pp. 22-227, of Ins 1968. ula tin g 56. MMPPnrcooeDrugotmranelaosilcstdyo, nRJiieon.psoiCtsrht.e,(PILCCreO.hs)rEe,yn.sBtoeRutdoiclhseasatirPteerIVsortd,, uIGn1c9.itne7gEr1ny.Iasnstdieonun,satarlyndCooAfn.fQeDrue.enbMcececD: oonnAald . 57. Wright, G. W. Saint Luke's Hospital, Cleveland, Ohio, personal communication, 1970. 58. Murphy, and E. N. Eng. R. A. J. L. H., G. Gaensler. Med., Vol. C. Ferris, Effects of 285, pp. Jr., W. A. Burgess, Low Concentrations 1271-1278, 1971. J. of Worcester, Asbestos, VII-4 59. Murphy , R. L. , W. A. Burgess. Exposure. Am. B. W. Levine, F. J. AlBazzaz, Floor Tile Ins tallation as a Rev. Resp. Dis., Vol . 104, pp. J. J . Lynch, and Source of Asbestos 576-580, 1971. 60. McC lure, Bureau of Labor Standards , U. S. Department of Labor, personal COillllunication, 1970. bL Ayer, H. E., J. R. Lynch, and J. H. Fanney. Impinger and Membrane Filter Techniques for i n Asbestos Plants. Ann. N. Y. Acad. Sci., A Comparison of Evaluating Air Samples Vol . 132, pp. 274- 287, 1965. 1>2. La ne, Dust. R. E. Ann. et al. Occup. Hygiene Standard for Chrysotile Hyg., Vol. 11, pp . 47-49, 1968. Asbest os 6 3. Dreessen, and R. R. Industry . W. C., J. M. Dallavalle, J. I. Sayers. A Study of Asbestosis Edwards, J. W. Miller , in the Asbestos Textile Public Health Bulleti n No . 241 , 1938. 64. Lynch, .J. R., H. E. Ayer, and of Selected Asbestos Exposure D. L . Johns on. The Interrelationship Indices. Arn. Ind . Hyg. Assoc. J. , Vol . 12, pp. 598-604, 1970. 65. Gee, B., England J and A. . Med., Bouhuys. Vol. 285, Action on pp. 1317 - Asbes 1 31 8 , tos-1971. Edi to r ial . New 66 . -- - - the Asbest Pr odu c ti vi Standa r d os Regula t y Her Ma f or Asbestos tions, 1969. jes ty's Facto Dust Concentration for Use with Department of Employment and ry Inspectora~e. Technical No te 13 , 1970. 67 . Roach , S. A. Hygiene Standards for Asbestos. Ann . Occup. Hyg., Vol. 13, pp. 7-15 , 1970. 68. - in - - the Wor Documen t a tion of t k Room Air, ACGIH, he Thresho ld 3rd Edition, Limit 1971. Values for Substances 69. Controls. Asbestos-Nat. Acad. The Need for and Fea Sci. , Washington, D. sibility of C., 1971. Air Pollutlon 70. Noti ce of Proposed Final Draft : Illinois Po lluti on Control Board, 1971. As bes tos Regulations. 71. Edwards, Health Se Filters. G. H., rvice Ann~ and J. R. Lynch . for Enumeration o Occup. Hyg., Vol. f The Method Used by the Pu Asbestos Dust on Membrane 11, pp. 1-6, 1968. b l ic 72. Lyncl1, J. Exposure R., H. E. Ayer, and D. L. to Airborne Mineral Fibers. J ohnson. The Measurement of Presented at the Am . Ind. Hyg. Assoc. Conf. , Denver, 1969 . VII-5 73. Ayer, H. E., and J . R. Lynch . Motes and Fibers in the Air of Asbestos Processing Plants and Hygienic Criteria for Airborne Asbestos . Proceedings of an Internati onal Symposium Organized by the British Occupational Hygiene Society, pp. 511-522, 1965. 74. Lynch, J. R., and H. E. Ayer. Measurement of Asbest os Exposure . J. Occup. Med., Vol. 10, pp. 21-24, 1968. 75. Lynch, J. R. and H. E. Ayer. Meas urement of Dust Exposure in the Asbestos Textile Industry. Am. Ind. Hyg. Assoc. J., Vol. 27, pp. 431-437, 1966. 76. Keenan, R. G., and J. R. Lynch. Techniques for the Detection, Identification and Analysis of Fi bers. Am. Ind. Hyg. Assoc. J., Vol. 31, pp . 587-597, 1970. VII- 6 VIII. APPENDIX I Air Sampling Methods 63 In the study of asbestosis conducted by Dreessen!!_ al. midget impinger count data were used as an estimate of dust exposure. All of the dust particles seen, both grains and fibers, were counted since too few fibers were seen to give an accurate measurement. The resulting count concentration was a measure of overall dust levels rather than a specific measurement of the asbestos concentration. This method was satisfactory at that time since exposures were massive and the control measures installed to reduce overall dust l evels also reduced the asbestos dust levels. As dus t levels were reduced, it became necessary to measure the biologically appropriate attribute of the dust cloud. At equal levels overall dustiness, the concentration of asbestos could vary considerably from textile manufacture (75-85%) to insulation (5-15%). furthermore, if the limit were lowered below the 5 mppcf used previously and dust counts taken by the impioger technique, it would be necessary to consider the effect of background dust, which could be as high as 1 mppcf. A number of methods for measurement of asbestos dust concentrations have been used in the NIOSH epidemiological study of the asbestos product industry. 73,74,75,76 Based on t hese data , the pre f erred index of asbestos exposure is the concentration of fibers longer than 5 ;im counted on membrane filters at 430X with phase contrast illumination. 71,72 This index i s utilized in the method adopted as the standard field sampling method by the Public Health Service. Vlll-1 Fibers longer than 5 ~m in length are counted in preference to counting all fibers seen in order to minimize observer/microscope resolving power variability. Furthermore, the British define a "fibre" as a particle, "of length between 5 )lm and 100 pm and having a length-to-breadth ratio of at least 3:1, observed by transmitted light by means of a microscope 62 at a magnification of approximately 500X." Although the British have refrained from standardizing on a single method of measurement, recent measurements have been performed by a method essentially identical to the fiber-count method described in detail below, and the British hygiene st andards for use with their 62 asbestos regulations are stated in these terms. Principles of Sampling A dust sampling procedure must be designed so that samples of actual dust concentrations are collected accurately and consistently. The results of the analysis of these samples will reflec~ realistically 1 the concentrations of dust at the place and time of sampling. In order to collect a sample representative of airborne dust, which is likely to enter the subject's respiratory system, it is necessary to position a collection apparatus near the nose and mouth of the subject or in his "breathing zone". The concentration of dust in the air to which a worker is exposed will vary, depending upon the nature of the operation and upon the type of work performed by the operator and the position of the operator relative to the source of the dust. The amount of dust inhaled by a worker can vary daily, seasonally, and with the weather. In order to obtain representative samples of workers' exposures, it is necessary to collect saaples under varying condit i ons of weather, on ~~fferent Vlll-2 days, and at different times during a shift. 7he percentage of working time spent on different tasks will affect the concentration of dust the worker inhales since the different tasks usually result in exposure to different concentrations. The percentage can be determined from work schedules and by observation of work routines. Tbe daily average weighted exposure can be determined by using the following formula: (Hours X cone. task A) + (Hours X cone. task B) + etc. 8 H6Uie (or actual hours worked) The concentration of any air contaminant resulting from an industrial operatJon also varjes with time. Therefore, a longer sampling time wjll better approximate the actual average. With the following recoUUDended sampling procedure, it is possible to collect samples at the workers' breathing zones for periods from 4 to 8 hours, thus permitting the evaluation of average exposures for a half or full 8-hour shift--a desirable and recoDUDended procedure. Furthermore, dust exposures of a more normal work pattern result from the use of personal samplers. In evaluating daily exposures, samples should be collected as near as possible to workers' breathing zones. Collecting Sample The method recommended in this report for taking samples and counting fibers is based on a modification of the membrane filter method described by Edwards and Lynch. 71 VIII-3 The sample should be collected on a 37-millimeter Millipore type AA* filter mounted in an open-face filter hol der . The holder should be fastened to the worker's lapel and air drawn through the filter by means of a battery-powered personal sampler pump similar to those approved by NIOSH under the provisions of 30 CPR 74 . The filters are contained in plastic filter holders and are supported on pads which also aid in controlling the distribution of air through the filter . To yield a more uniform sample deposit, the filter-holder face-caps should be removed. Sampling flow rates from 1.0 liter per minute (lpm) up to the maximum flow rate of the pers onal sampl er pump (usually not over 2.5 lpm) and sampling time from 15 minutes to eight hours are acceptable provided the following restraints are considered: (a) In order to obtain an accurate estimate of the number of fibers the statistical error r esulting from the random distribution of the fibers must be kept to an acceptably low level. Since fiber counts follow a Poisson distribution, a count of 100 fibers in a sample would have a standard deviation of IOU or 10 fibers or + 10%. Thus the 95% confidence limits would be approximately 2 standard deviations or + 20%. Since t he 37 mm filter has an effec- tive collecting area of 855 mm2 and the projected field area of the Porton reticle is 0.005 mm2 , each field represents 1/171000 of the sample. Based on this ratio the following number of fields mus t be counted to measure the various limits in various sampling times: *Mention of the Public commercial products Health Service or U. does S. not const Department itute endorsement by of Health, Educatio n dnd Welfare. Vlll- 4 Sampling Time Minutes 10 15 30 90 90 240 240 480 Flow Rate lpm 2 2 2 1 2 1 2 1 0.2 Number fibers/ml of Fields for 100 Fibers 2.0 fibers/ml 10 fibers/ml 4350 2860 1430 1000 500 260 180 180 435 286 143 100 50 26 TI 18 91 58 29 20 10 7 4 4 (b) Do not count a field conta i ning over 20 fibers because in addition to the fibers being counted, there are also present a number of grains, which interfere with the accuracy of the count. Based on these restraints, i.e., number of fields to be counted and maximum number of fibers per field, acceptable sampling parameters for the various limits are underlined in the above table. The following conclusions may be drawn from this analysis: (1) The short-term limi t should be for a period of at least 15 minutes and preferably 30 minutes. (2) The 2.0 fiber/cc l i mit may be evaluated over periods of from 90 to 480 minutes. AB many fields as required to yield at least 100 fibers should be counted. In general the minimum number of fields should be 20 and the maximum 100. Mounting Sample The mounting medium used in this method is prepared by dissolving 0.05 g of membrane filter per ml of 1:1 solution of dimethyl phthalate Vlll-5 and diethyl oxalate. The index of refraction of the medium thus prepared is ND 1.4 7. To prepare a samp l e for microscopic examination, a drop of t he mounting medium is placed on a freshly cleaned, standard (25 mm X 75 mm), microscopic slide. A wedge-shaped piece with arc length of about 1 cm is excised from the filter with a scalpel and forceps and placed dust-side-up on the drop of mounting solution. A No. 1-1/2 coverslip, carefully cleaned with lens tissue, is placed over the filter wedge. Slight pressure on the coverslip achieves contact between it and the mounting medium . The sample may be examined as soon as the mount is transparent. The optical homogeneity of the resulting mount is nearly perfect, with only a slight background granularity under phase contrast, which disappears within one day. The sample should be counted within two days after mounting. Evaluation The filter samples mounted in the manner previously described are evaluated in terms of the concentration of asbestos fibers greater than 5 pm in length. A microscope equipped with phase-contrast optics and a 4-mm "high-dry" achromatic objective is suitable for this determination. lOX eyepieces, one of which cont ains a Porton or other suitable reticle at the level of the field- limiting diaphragm, should be used . 11le left half of the Porton reti cle field serves to define the counting area of the field. Twenty fields located at random on the sample are counted and total asbestos fibers longer than 5 Jlm are recorded . Any particle having an aspect ratio of three or greater is considered a fiber. Vlll-6 The following formulae are used to determine the number of fibers/ml: (1) Filter area (llllll2) Field area (mm2) sK (2) Average net count X K a fibers/ml Air volume sampled (ml) For example, assume the following: area of the filter used was 855 mm2 , counting area of one field under the Porton reticle was 0.005 mm2 ; average net count per field of 20 fields was 10 fibers; and sample was collected at 2 liters per minute for 90 minutes: Then: 855mm2 c 171,000 (K) 0.005 nun2 10 fibers x 171,000 2,000 ml/min x 90 min 9.5 fibers/ml Calibration of Personal Sampler The accuracy of an analysis can be no greater than the accuracy of the volume of air which is measured. Therefore , the accurate calibration of a sampling device is essential to the correct interpretation of an instrument's indication. The frequency of calibration is somewhat dependent on the use, care, and handling to which the pump is subjected. Pumps should be calibrated if they have been subjected t o misuse or if they have just been repaired or received from a manufacturer. If hard usage is given the instrument, more frequent calibration may be necessary. Ordinarily, pumps should be calibrated in the laboratory both before they are used in the field and after they have been used to collect a large number of field samples. The accuracy of calibration is dependent on the type of instrument used as a reference. The choice of calibration instrument wil1 depend largely upon where the calibration is to be performed. For laboratory testing, a 1-liter burette or wet-test meter should be used. In the field, a rotameter is the most convenient VIII-7 instrument used. The actual set-up will be the same for all of these instruments. The calibrati on instrument will be connected in sequence to the filter unit which will be followed - by the personal sampler pump. In this way, the calibration instrument will be at atmospheric pressure. Connections between units can be ~de 'using the same type of tubing used in the personal sampling unit. Each pump must be calibrated separately for each type of filter uaed, if, for example, it has been decided to use a filter with a different pore size. The burette should be set up so that the flow is toward the narrow end of the unit. Care must be exercised in the assembly procedure to insure adequate seals at the joints and that the length of connecting tubing be kept at a minimum. Calibration should be done under the same conditions of pressure, temperature and density as will be encountered. The rotameter should be used only in the field as a check if the diaphragm or piston pumps are not equipped with pulsation dampeners. The pulsating flow resulting from these type pumps causes the rotameter to give results which are not as accurate as that obtained with a burette or wet-test meter. Calibration can be accomplished with any of the other standard calibrating instruments, such as spirometer, M.artiott's bottle, or drygas meter. The burette and wet-test meter were selected because of their accuracy, availability, and ease of operation. VIll-8 IX. APPENDI X II NUMERICAL HAZARD RATING SYSTEM Th.:! 11umerical hazard ratings given to products for each category of hazard shall be i n accordance with t he following criteria. Figure 2 graphicdlly illustrates the hazard identification system. Health hazards shall be rated as follows: "f he hedlth hazard rating of a material s hall be determined by eva lua ting the potential for exposure and the relative toxicity of the most toxic ingredient of a compound or mixture. For this evaluati on, ti.~ c '~ l lu1.:ing relative toxicity criteria* for absorbed or exposun:: dose will be used: Commonly Used Tenn DLDo5s0e Simple Oral Rate mg/kg Inhalation 4-hr. Vapor Exposure, Rats Mortality of 2/6 to 4/6 ppm LD50 - Skin Rabbits ID8/kg Extremely toxic Highly toxic Moderately toxic 1 1.1 to 50 50.1 to 500 LlO 11 to 100 101 to 1000 L5 5.1 to 43 44 to 340 Slightly toxic or practically non-toxic 501 to 15,000 1,001 to 100,000 350 to 22,600 Relatively harmless 15,000 100,000 22 ,600 Degree 4: Extremely Hazardous. Materials, which on very short exposure, can cause death or major permanent injury, even though prompt medical treatment were given, including those which are too dangerous to be approached without specialized *(Referen~e:--A.I.H.A . Quarterly, Vol. 15 , No . 2, Procedures for Compounds Developed by the Petro June 1954. "Safe Handling Chemical Industry," p. 141.) IX-1 protective equipment, such as self-contained breathing apparatus or a hose mask with blower, and impervious clothing. This rating includes: (a) Carcinogens (b) Materials capable of producing sensitizat ion (c) Extremely toxic materials which can penetrate ordinary protective clothing. (d} Extremely hazardous materials, when under normal conditions give off gases that are extremely toxic or corrosive through inhalation or by contact with or absorption through any body surface. Degree 3: Highly Hazardous. Materials which on short exposure can cause serious temporary or residual injury, even though prompt medical t reatment were given, includtng those requiring protection from all bodily contact. This rating includes: (a) Materials giving off highly toxic combus tion products (b) Materials giving off highly toxic gases or vapors, under normal conditions (c) Materials corrosive to living tissue or highly toxic by skin absorption Degree 2: Hazardous. Materials which on continued exposure ca n cause temporary incapa- citation or possible residual injury unless prompt medical treatment is given. This rating includes: (a) Materials giving off moderately toxic combustion products (b) Materials which either under normal conditions or under fire conditions give off moderately toxic vapors lacking warning properties. Degree 1: Slightly hazardous. Materials, which on exposure at normal conditions, would cause irritation but only minor residual injury even if no treatment ie given. IX-2 This rating includes: (a) Materials which under fire conditions give off slightly t oxic or irritating combustion products (b) Materials which on the skin could cause ixtitation without destruction of tissue Degree U: Harmless . Materials which on exposure . by skin contact, inhalation, or ingestion are relatively harmless or which unrl e r fire condition s offer no hazard beyond that of ordinary combustible materials. Flammability hazards shall be rated as follows: Degree 4. Materials which will rapidly or completely vaporize at atmospheric pressure and normal ambient temperature or which are readily dispersed in air, and which will burn readily. This degree should include: Gaseous materials: Cryogenic materials; any liquid or gaseous material which is a ljquid while under pressure and having a flas h point below 73F (22 .8 C) and having a boiling point below 100F (37.a~c). (Class lA flallJllable liquids.) Materials which on account of their physical form or environmental conditions can form explosive mixtures wi th air and which are readily dispersed in air, such as dusts of combustible solids and mists of flammable or combustible liquid droplets. Degree 3. Liquids and solids that can be ignited under almost all ambient temperature conditions. Materials in this degree produce hazardous l.X-3 atmospheres with air under almost all amb i ent temperatures, are readily ignited under almost all conditions. This degree should include: Liquids having a flash point below 73F (22.8C) and having a boiling point at or above 100F (37.8C) and those liquids having a flash point at or above 73F (22.8C) and below 100F (37.8C). (Class lB and Class lC flammable liquids); Solid materials in the form of coarse dusts which may burn rapidly but which generally do not form explosive atmosphere with air; Solid materials in a fibrous or shredded form which may burn rapidly and create flash fire hazards, su ch as cotton, sisal and hemp; Solids which burn with extreme rapid i ty usually by reason of self-contained oxygen (e.g., dry nitrocell ulose); Materials which ignite spontaneously when exposed to air. Degree 2. Materials that must be moderately heated or exposed to relatively high ambient temperatures before ignition can occur. Materials in this degree would not under normal conditions form hazardous atmospheres with air, but under high ambient temperatures or under moderate heating may release vapor in sufficient quantities to produce hazardous atmospheres with air. This degree should include: Liquids having a flash point about l00F, but not exceeding 200F; solids and semisolids which readily give off flalmlable vapors. Degree i. Materials that must be preheated before ignition can occur. Materials in this degree require considerable preheating, under all ambient temperature conditions, before i gnition and combustion can occur. IX-4 Tilie degree should include: Materials which will burn in air when exposed t o a temperature of 1500F for a period of five minutes or lees; Liquide, solids and semisolids having a flash point above 200F; this degree includes most ordinary combustible materials. Degree O. Materials that will not burn . Tilis degree should include any material which will not burn in air when exposed to a temperature of 1500F for a period of five minutes. Reactivity hazards shall be rated as follows: Degree 4. Materials which are readily capable of detonation or of explosive decomposition or explosive reaction at norm.al temperatures and pressures. Tilis degree should include materials which ere sentitive to mechanical or localized thermal shock at normal temperatures and pressures. - Degree 3 Materials which are capable of detonat ion or of explosive decomposition or explosive reaction but whi ch require a strong initiating source or which must be heated under confinement before initiation. This degree should include materials which are sensitive to thermal or mechanical shock at elevated temperatures and pressures or which react explosively with water without requiring heat or confinement. Degree 2. Materials which are normally unstable and readily undergo violent chemical change but do not detonate. This degree should include materials which can undergo chemical change with rapid release of energy at normal IX-5 termperatures and pressures or which can undergo violent chemical change at elevated temperatures and pressures. It should also include those materials which may react violently with water or which may form potentially explosive mixtures with water. Degree 1. Materials which are normally stable, but which may react with water with some release of energy but not violently. Degree 0. Materials which are normally stable, even under fire exposure conditions, and which are not reactive with water. Specif~c hazards: Oxidizing Material. A substance as chlorate, permanganate, peroxide, or a nitrate that yields oxygen to suppor t combustion or which reacts readily to oxidize fuels or other combust ible materials. Corrosive Material. Acids, alkali or other material that will cause severe damage to living tissue or to oth er material it contacts. Water Reactivity Hazard (Use No Water). Any material that may be a hazard because of its specific reactivity with water. IX-6 r------------- ---- HE~Lrn 1:1.u nu '1 Ei trrmct1 ho:r.rdovs 3 Highly h111 11tc1o u~ 2 Hozor\ltu s I Slighlly hC\H, rcl .'l " ~ 0 ll or ml ns ~ FIRE llAZ/.fiO ~~ ~ .....:~ flosh Poin t 4 Or lo11 7:,''f @ 3. Elrlow lt10F 2 Ut lo w 7.00'.. f 1 At.ovr 2c0c-r ,,,,I ------."Sr I"I ,[::r ll '1 " 1 : '",I.'-., l'.'I'fl 1cL - .,. 11\L llr.i:;i,,: r - - - - Q):y A ticf - - - - - /1(".i) lll~o t i - - - - - l\L K ( 01 r c.. ~. i \'C - --- - COH ,.,,,TEl!s(.' 110 r. '--- "'"~ II t b1 d ~lr.rolc 3 Shoct rnd h~o l ?. V i:.:!r 1 t :.c.. :;lit !; : =i 1(,:'I(,; ~ I Un!.IC! ~ : ~ it t.!:'l1\!'ci ll ~l ob!: COLOH /\ND DI:\IJ::;-:SJON C ol o1' for m ~ l f or NEPA No. 7 MM tl c~~i g1i::itlnn~ arr f;JJ iJ\\'11 nhovc . The cul ors indi c::.~ 1l~cl shall !t(;C:cpt:1bly m;d d1 in };)J :ick th0. Rpplie;)blc l;Ol n1 o f FED-STD - GD~ a s follow::; : Col or Cl <lr.~ l3liwk n ccl Whit e Yellow m ue 170:1 H 1J l 0:1 1787G J ~G:Jn 15J O'.~ Dimr.nni onn option:il lmt of cf the ~ymh ol arnl LAP J w:1 r n ine- c omhi n :lli o n sh ~Jl b e such si ze :m<l loc ati on m: t o b e rcau ily viuiblo ~.1.ncl lui,~iblc . Tho :;ymbcl r. rnl warn in;: r. li .1~! be :1pp l it:rl Ly s l t! 11c i li n 1 ~ . p a in ti ng , pl' inli ng , l il li o~~ rnph i u3-, wi ih f:1d c:-rr :: ;i: : ~:1nl m:11eri:Lh :. IX- 7 X. APPENDIX III MATERIAL SAFETY DATA SHEET The following items of information which are applicable to a specific product or material containing 5% or more of asbestos shall be provided in the appropriate section of the Material Safety Data Sheet or approved form. If a specific item of information i s inapplicable (i.e. flash point) initials 11n.a. 11 not applicable should be i nserted. (i) The product designation in the upper left hand corner of both front and back to facilitate filing and retrieval. Print in upper case letters in as large print possible. (ii) Section I. Name and Source (A) The name, address and telephone number of the JD.8nufacturer or supplier of the product. (B) The trade name and synonyms for a mixture of chemicals, a basic structural material. or for a process material; and the trade name and synonyms. chemical name and synonyms. chemical family. and formula for a single chemical. (iii) Section II. Hazardous Ingredient s. (A) Chemical or widely recognized co111110n name of all hazardous ingredients. (B) The approximate percentage by weight or volume (indicate basis) which each hazardous ingredient of the mixture bears to the whole mixture. This may be indica ted as a range of maximum amount. i.e . 10-20% V; 10% max. W. X-1 (C) Basis for toxicity for each hazardous material such as establ~shed OSHA standard (TLV), in appropriate units and/or Ln 50 , showing amount and mode of exposure and species or Lc50 showing concentration and species. (iv) Section III. Physical Data (A) Physical properties of the total product including boiling point and melting point in degrees Fahrenheit; vapor pressure, in millimeters of mercury, vapor density of gas or vapor (air D 1), solubility in water, in parts per hundred parts of water by weight; specific gravity (water l); percent volatile, indicate if by weight or volume, at 70 Fahrenheit; evaporation rate for liquids (indicate whether butyl acetate or ether l); and appearance and odor. (v) Section IV. Fire and Explosion Hazard Data. (A) Fire and explosion hazard data about a single chemical or a mixture of chemicals, including flash point, in degrees Fahrenheit; flammable limits, in percent by volume in air; suitable extinguishing media or agents; special fire fighting procedures; and unusual fire and explosion hazard information. (vi) Section V. Health Hazard Data. (A) Toxic level for total compound or mixture, relevant symptoms of exposure, skin and eye irritation properties, principle routes of absorption, effects of chronic (long-term) exposure and emergency and first aid procedures. (vii) Section VI. Reactivity Data. (A) Chemical stability, incompatibility, hazardous decomposition products, and hazardous polymerization. (viii) Section VII. Spill or Leak Procedures. (A) Detailed procedures to be followed with emphasis on precautions to be taken in cleaning up and safe disposal of materials leaked or spilled. Thie includes proper labeling and disposal of containers containing reaiduee, X-2 contaminated absorbants, etc. {ix) Section VIII. Special Protec tion Inf ormation . {A) Requirements for personal protect i ve equipment, such as respirators , eye protection and prot ec tive clothing, and ventilation such as local exhaust (at site of product use or application), general, or other special types. {x) Section IX . Special Precautions . {A) Any other general precautionary information such as personal protective equipment for exposure to the thermal decomposition products listed in Section VI, and to particulates formed by abrading a dry coating, such as by a power sanding disc. (xi) The signature of the responsible person filling out the data sheet, his address, and the date on which it is filled out. (xii) The NFPA 704M numerical hazard ratings as defined in section (c) (5) following . The entry shall be made immediately to the right of the heading "Material Safety Data Sheet" at the top of the page and within a diamond symbol preprinted on the forms. X-3 . ?RODUCT DESlGN1\'l'lON !'\l t.l{lHL ~~ l:. I Y DATA SITTT Form Approved Budget Bureau No. Approval Expires Form No . OSHA SECTJON I SOURCE AND NOMENCLAT URE MANUFACTURER ' S NAME EMERGENCY TELEPHONE NO . ADDRESS (Number, Street , City, State , ZIP Code) TRADE NAME AND SYNONYMS CHEMICAL FAMILY CHEMICAL NAME AND SYNONYMS FORMULA BASIC MATERIAL SECTION JI HAZARDOUS INGREDI ENTS APPROXIMATE OR MAXIMUM %WT. OR VOL. ESTABLISHED OSHA STANDARD LD50 ORAL PERCUT. I LC50 SPECIES CONC. -- --- - - - -- ---- BOILING POINT SE CTI ON JI I PHYSICAL DATA oF. VAPOR PRESSUHE MELTING POINT oF. VAPOR DENSITY (Air:::l) SPECIFIC GRAVI'fY (H20=l) SOLUBILITY IN WATER Pts/100 pts H20 EVAPORATION RATE ( VOLATILE ==l) %Vol. APPEARANCE AND ODOR FLASH POINT METHOD USED SECTION JV FIRE AND EXPLOSION HAZARD DATA FLAMMABLE (EXPLOSIVE ) LIMITS mm Hg. %Wt. UPPER LOWER EXTINGUISHING MEDIA SPECIAL FIRE FIGHTING PROCEDURES UNUSUAL FIRE AND EXPLOSION HAZARDS X-4 PRODUCT DESIGNATION SECTION V HEALTH HAZARD DATA TOXIC LEVEL PRINCIPLE ROUTES OF A.BSORBTION RELEVANT SYMPTOMS OF EXPOSURE CARCINOGENIC SKIN AND EYE IRRITATION EFFECTS OF CHRONIC EXPOSURE EMERGENCY AND FIRST AID PROCEDURES SECTION VI REACT! VITV DATA CONDITIONS CONTRIBUTING TO INSTABILITY CONDITIONS CONTRIBUTING TO HAZARDOUS POLYMERIZATION INCOMPATABILITY (Materials to Avoid) HAZARDOUS DECOMPOSITION PRODUCTS SECTION VII SPILL OR LEAK PROCEDURES STEPS TO BE TAXEN IN CASE MATERIAL IS RELEASED OR SPILLED WASTE DISPOSAL METHOD SECTION VIII SPECIAL PROTECTION INFORMATION VENTILATION REQUIREMENTS LOCAL EXHAUST MECHANICAL (General) PROTEC~IVE EQUIPMENT (Specify Types ) EY-E GLOVES SPECIAL RESPIRATOR OTHER PROTECTIVE EQUIPMENT SECTION IX SPECIAL PRECAUTIONS PRECAUTIONS TO BE TAKEN IN HANDLING AND STORAGE OTHER PRECAUTIONS Signature Address Date X-5 Ol'EUTION Varebouain1 ' 'Kixiog Pip l'ondng Curil21 Pipe l'iniebiog Coupling l'in!ebing Epoxy Paclt1D1 Mt.ce.lhn.oua HIGHEST INDIVIDUAL SAMPLE 7.0 3. 7 2.6 4.6 13.4 4.7 6 .1 1. 7 SAMPLE S"LZE YROH WlHCH tNI>IvtDUAL SAMPU DRA\l!I 2 6 3 10 7 l 1 9 'I>JILE I CEliENT Pil'E PI.ANTS NUMllER 01' PLA)ITS , INDIVIDUAL SAMPLES BY OPERATION AND SAMPLE SIZE PLANT SECOND HIGHEST I?IDIVIDUAL SAMPLE SAMPLE SIZE l'ROK lil!ICll INDIVIDUAL SAXPLE DRAWN PLANT SECOND LOVfST INDIVIDUAL SAXl'l.E 0 S. 6 0 3.4 0 2.1 z 4.0 z 10.5 II 2.1 Q 2. 5 z 1. 4 2 0 0.2 3 N 0. 1 15 1111 0.1 s Q 0.0 7 z 0.0 6 BB 0.3 7 z 0.1 9 p 0.1 SAMPLE SIZE YROK WRI Cl! INDIVIDUAL Ill.ANT S AMPLE DRAWN ~ST INDIVIDUAL SAMPLE SAMPLE SIZE nDM WllICR INllIVIDUAL SAMPLE DRAWN PLANT 3 p 0.2 4 I 6 0 o.o I I 6 4 z o.o 6 6 II o.o 10 16 p o.o 21 s z 0.2 6 13 u o.o l) 9 p o. o 9 Q M p z M BB M z l - All &11plee expreeed fiben >~/cc counted by the atandard . .thod reco-nded in thh docU9ellt. (Lateet Available NIOSB Dt Collected durin& tba TeAr 1969 throuab 1970). OPERATION Warehousing & Mixing Pipe Forming Curing Pipe Finishing Coupling Finishing Epoxy Packing Miscellaneous TABLE II ASBESTOS CEMENT PIPE PLANTS NUMBER OF PLANTS 7 MEANS BY OPERATION AND SAMPLE SIZE ( ) HIGHEST PLANT SECOND HIGHEST PLANT SECOND LOWEST PLANT 6. 3 (2) 2.2 (3) 2. 0 (3) 1. 7 (10) 5. 3 (7) 4. 7 (1) 6.1 (1) o. 5 (9) 0 N 0 z z N Q z 2.7 (4) 1.8 (4) 0.9 (15) 1.3 (5) 3.8 (4) 1.1 ( 6) 1.1 ( 7) 0.5 (6) N z BB Q 0 BB z BB 0. 7 (5) o. 5 (6) 0.4 (4) 0.6 (9) 0.6 (21) 0. 6 (6) 0. 7 (6) 0.4 (9) AA AA z AA AA p BB p I I LOWEST PLANT 0.4 (3) 0.3 (4) 0. 3 (6) 0. 5 (6) 0. 5 (16) o. 3 (1) o. 4 (13) o; 2 (3) p p p N p AA AA Q 1 - All samples expressed as fibers:;;io-5u /cc counted by the standard method reco1m11ended in this document . (Latest Available NIOSH Data Collected during the years 1969 through 1970) . OPERATION HIGHEST INDIVIDUAL SAMPLE TABLE III ASBESTOS FRICTION NUMBER OF Pt.ANTS 5 INDIVIDUAL SAMPLES BY OPERATION AND SAMPLE SIZE SAMPLE SIZE FROM 11111 CH INDIVIDUAL SAMPLE DRA\IN PLANT SECOND HIGHEST INDIVIDUAL SAMPLE SAMPLE SIZE FROM WI!I CH INDIVIDUAL SAMPLE DRA\IN PLANT SECOND LOWEST INDIVID. SAMPLE SAMPLE SIZE FROM WHICH INDIVIDUAJ. SAMPLE DRAWN I PLANT . LOWEST INDIVIDUAL SAMPLE SAMPLE SIZE FROM WliI CH INDIVIDUAL SAMPLE DRAWN PLA?IT Mixing, Coating & Extruding 32.4 Pot'Ung 16.2 Bot Prudng 7.3 Baking 7.4 Grinding & Sanding 20.5 Cutting & Drilling 14.4 Bonding & lliveting 8.7 Inap~ti.on & Packing 11. l Mt.cellaneota 6.4 16 s 18.4 3 u 9.2 5 s 6.0 5 s 7.3 8 T 16.6 22 s 14.4 4 B 1. 5 4 s 9.9 9 H 6.4 16 4 5 5 16 22 4 13 9 s 0.1 s 0.3 s 0.2 s 0.5 s 0.1 s 0.4 !! 0.2 H 0.1 H 0.1 7 6 7 2 10 12 l 13 5 M 0.1 H O.l ,, 0.1 M O. l !! 0.1 l! 0.1 T 0.1 H O.l T 0.1 7M 6H 7H 2 !! 10 H 7M lM 13 B 9B l - All samples vcpru11ed aa fibers ')';p/cc counted by the standard method recoanended in this document. (Latest available NIOSH Data collected during the years 1968 through 1971) . OPERATION Mixing, Coating & Extruding Forming Hot Pressing Baking Grinding & Sanding Cutting & Drilling Bonding & Riveting Inspection &Packing Miscellaneous TABLE IV ASBESTOS FRICTION PLANTS NUMBER OF PLANTS - S MEANS BY OPERATION WITH SAMPLE SIZE ( ) HIGHEST PLANT 2nd HIGHEST PLANT 2nd LOWEST PLANT LOWEST PLANT 11. 0 (16) 6. 0 (3) 4.9 (5) S.4 (5) 6.3 (4) 14.4 (1) 2.8 (4) 5.1 (4) 2.2 (9) s u s s u u H s H 5.3 (2) 3.6 (4) 1.5 (2) 3. 7 (1) 5.2 (16) 7. 7 (22) H s u u s s 3. 7 (3) 1. 4 (1) u M 4.3 (2) o.s (2) 1. 4 (4) 0.6 (2) 2. 7 (7) 0.9 (7) 0.2 (1) 1.0 (4) o. 8 (3) u T M M M T T M u 1.9 (7) 0. 5 ( 6) 0. 7 ( 7) 0. 4 (2) 1.1 (10) 0.6 (7) 0.1 (1) 0.9 (7) 0.5 (5) M H H H H M M I T 1 - All in samples expressed as fibers >Sp/cc counted by the this document. (Latest available NIOSH data collec standard method recommended ted during the years 1968 through 1971). .OPERATION liarehou. ing IUJ<iog Pond.cg Curing Fintshing Packing Miscellaneous RIGHE ST DIDIVlDUAL SAMPLE TABLE V ASBESTOS CE:ME>IT SHINGLE, KILL BOARD AND GASICET NUMBER OP PLANTS 3 INDIVIDUAL SAMPLES RY OPERATION AND SAMPLE SIZE SAMPLE SIZE P'ROM \olHICR D!DIVIDUAL SAMPLE PLANT DRAWN SECOND BICHEST INDIVIDUAL SAMPLE .SAMPLE SIZE FROM \.IBICR INDIVIDUAL SAMPLE DRAWN PLANT SECOND LO WE ST INDIVID. SAMPLE ~AMPL E SIZE P'ROM lolHI CH INDIVIDUAL SAMPLE DR.4WN 1. 4 16.6 6.4 2.5 5.4 3.8 1. 4 3 R 0.4 15 R 9 .5 18 R 3.7 2 R 1. 6 17 R 4.4 4 R 1.1 2 w 1. 2 3 R 0.2 3 6 w 0 . .5 6 3 w 0.1 18 2 v 0.4 17 R 0.1 7 2 w 0.2 4 R 0.9 1 PLANT R w R w v w .,, LOWEST INDIVID. SAMPLE SAMPLE SIZE !'ROH WllI CH INDIVIDUAL SAMPLE DRAWN PLANT 0.1 l 0.3 1.5 0.0 18 0.2 2 0.1 I 7 0.1 4 0.6 4 v R R R w R R l - Al l samples recommended expressed aa fibers '7~ /cc in this docW11ent. (L~test counted by the atandarc method av~ilablr NIOSR data coll~cted during the years 1966 thr ough 19 70). OPERATION Warehousing Mixing Forming Curing Finishing Packing Miscellaneous TABLE VI ASBESTOS CEMENT SHINGLE, MILLBOARD NUMBER OF PLANTS = 3 AND GASKET MEANS BY OPERATION AND SAMPLE SIZE ( ) 2nd 2nd HIGHEST PLANT HIGHEST PLANT LOWEST PLANT 0. 7 (3) 4.4 (6) 2. 6 (3) 1.5 (2) 1.9 (17) 1.2 (4) 1. 2 (2) R w 3.8 (15) w 1. 3 (18) v 1.4 (2) R 1. 5 (2) R 0.7 (2) w 1. 0 (4) R R R w w R LOWEST PLANT 0 .1 (1) 1. 8 (1) 0 . 9 ( 6) 0. 4 (1) 1. 0 (7) 0.5 (2) o. 9 (1) v v v w v v v 1 - All samples expressed method recommended in as fibers ~SJJ / Cc counted by the standard this document. (Latest available NIOSH data collected during the years 1966 through 1970) . PRODUCT AREA Asbestos Paper TABLE VII ASBESTOS PAPER, PACKING, AND ASPHALT PRODUCTS INDIVIDUAL SAMPLES BY OPERATIONS AND SAMPLE SIZE* INDIVIDUAL HIGH OPERATION INDIVIDUAL LOW 10. 9 Asbestos Mixing 0.0 OPERATION Wood Mixing Paper Making Asbestos Packing 18 . 9 Weaving 0.1 Braiding Mixing & Calender P'orming Cutting & Trimming Asbestos Asphalt Products 16.3 Dry Mixing 0.0 * EOINNPVETIRRHAOETNSIMEOENTN.HTARELBEALSEAEVDSBELOESNSTOAINSTSOMPRAOHLDLIGUHNCETUSMTABREARENADOSF, LOPINLWASEUNSTTYSFIINCFDOIEIRVNITEDAUDCAHALTAPRSOAPRDMEUPVCLEETNATCSARETTAEAG, BOOURNLIELASYTINBTGYHE HIGH, LOW FOR INDIVIDUAL SAMPLES 'WERE DETERMINED. 1 - All samples expressed as fibers ~5p/cc counted by the standard method recollimended in this document. (Latest available NIOSH data collected during the years 1966 through 1970). Dry Mixing Wet Mixing Forming Finishing Inspection & Packing PRODUCT AREA TABLE VIII ASBESTOS PAPER, PACKING AND ASPHALT PRODUCTS MEANS BY OPERATIONS AND SAMPLE SIZE* HIGH MEAN OPERATION LOW MEAN OPERATION Asbestos Paper Asbestos Packing Asbestos Asphalt Products 3.4 13.6 2.4 Asbestos Mixing Weaving Dry Mix i n g 0.7 Miscellaneous 0. 2 Mixing &Calender 0.2 Forming Finishing *IN THESE THREE ASBESTOS PRODUCT AREAS, INSUYF'ICIENT DATA PREVENTS TABULATING ENVIRONMENTAL LEVELS INTO HIGHESTS, LOWEST MEAN CATEGORIES BY OPERATION. BASED ON A SMALL NUMBER OF PLANTS FOR EACH PRODUCT AREA, ONLY THE HIGH MEAN AND LOW MEAN 'WERE DETERMINED . 1 - All samples expres sed a s f ibers >5;.J / c c counted by the sta ndard method recommended in this document. (Latest available NIOSH data c ol lected during the years 1966 through 1970). <>PEUTION Mixing Ponrlna Curing Piahhiaa Inapection & Packing M11cellaneou.1 TABLE IX ASBESTOS INSULATION PLANTS NUMBER OP PLANTS - 5 INDIVIDUAL SAMPLES BY OPERATION AND SAMPLE SIZE HIGHEST INDIVIDUAL SAMPLE ,SAMPLE SIZE !'ROM WHI CB INDIVIDUAL SAMPLE DRAWN PLANT SECOND HIGHEST INDIVIDUAL SAMPLE SAMPLE SIZE PROM WI!I CH INDIVIDUAL PLANT SAMPLE DRAWN SECOND LOWEST INDIVID. SAMPLE SAMPLE SIZE PROM WRICH INDIVIDUAL SAMPLE DRAW PLANT 188.9 134.4 23.5 208.4 92.3 42.3 11 39 5 26 15 24 x 169.7 x 111.2 x 19.9 x 97.3 x 73.6 x 37.5 11 x 0 . 4 3 39 x 0.0 10 5 x l. 5 1 26 x 0.1 4 15 x 0.1 11 24 x 0.1 4 DD R DD cc R cc LO'WEST INDIVID. SAMPLE SAMPLE SIZE PROM \IBICl! DIDIVIDUAL SAMPLE D~WN 0.2 7 0.0 10 0.1 1 0.1 11 0.0 11 0.1 4 PLANT ll R cc R cc cc 1 - All 1aiaple1 expressed as fib ers )'5p/ cc counted by the 1tandard method recom11ended in thia document. (Latest available NIOSH data collected during the years 1966 through 1971). TABLE :X ASBESTOS INSULATION PLANTS NUMBER OF PLANTS 5 MEANS BY OPERATION AND SAMPLE SIZE ( ) OPERATION HIGHEST PLANT Mixing Forming Curing Finishing Inspection &Packing Miscellaneous 74. 4 (11) 50.6 (39) 14.4 (5) 39.5 (26) 22.8 (15) 16.6 (24) x x x x x x 2nd HIGHEST PLANT 46. 3 (7) 25.2 (32) y y 15.0 (17) 11. 0 (19) 2.7 (5) y y y 2nd LO'WEST PLANT 4 .1 (7) 0.7 (10) 1. 5 (1) 1.0 (11) 0. 5 (1) 2.6 (4) R R DD R R DD ' LOWEST PLANT 1. 7 ( 2) 0. 2 (7) 0 . 1 (1) 0.9 (4) 0.3 (11) 0.2 (4) cc cc cc cc cc cc 1 - All samples expressed as fibers >Sp /cc counted by the standard method recommended in this document. (Latest available NIOSH data collected during the years 1966 through 1971) . OPEllATION Fiber Preparation Carding Spinning !'wisting Winding Weaving Rope, Wick, Braid & Cord Finiahioa Micellaneoue TABLE XI LATEST SURVEY RESULTS ASBESTOS TEXTILE NUMBER OF PLANTS 8 INDIVIDUAL SAMPLES BY OPERA!TON AND TllE SAMPLE SIZE INDIVIDUAL SAMPLE WAS TAKEN FROM FIBERS/cc .Su HIGHEST INDIVIDUAL SAMPLE 120.3 l4J . 9 40.9 31. l 18.4 SAMPLE SIZE FROM WHICH INDIVIDUAL SAMPLE DRAWN PLANT SECOND HIGHEST INDIVID. SAMPLE 12 B 40 . 9 JO B 72 . 2 J6 R 28.7 7 I\ 25.3 24 B 17.9 SAMPLE SIZE FROM WICH INDIVIDUAL SAMPLE DRAWN PLAN7 4A JO B 4) B 8K 40 K SECOND LOWEST IND IV ID. SAMPLE SAMPLE SIZE FRCli WHICH INDIVIDUAL SAMPLE DRAWN PLANT LOWEST INDIVID. ~AMPLE SAMPLE SIZE !'ROM WICH INDIVIDUAL SAMPLE l!MWN 1.4 9 R 0.4 9 o. 7 2Z R 0.4 40 1.0 J6 R 0.4 4J 0.5 8 K 0.2 8 0.1 40 lC 0.0 40 123.2 11.0 5.6 37.0 57 3 3 2 8 38.5 D 10.3 G ).8 A 22.7 25 3 28 2 A O.l D 0.1 B 0.2 A 0.1 50 4 28 45 R 0.1 I( 0.1 B 0.1 K 0.1 50 3 28 45 PUNT K J B G K K D B K OPERATION Fiber Preparation Carding Spinning Twisting 'Winding Weavi.ng ~pe, Wick, Braid & Cord Miscellaneous Finishing TABLE XII LATEST SURVEY RESULTS ASBESTOS TEXTILE PLANTS NUMBER OF PLANTS ~ 8 MEANS BY OPERATION WITH SAMPLE SIZE ( ) FIBERS/CC )Su HIGHEST PLANT SECOND HIGHEST PLANT SECOND LOWEST PLANT 22. 3 (4) 27.3 (10) 12.5 (36) 14.S (7) 9. 7 (12) 12 .4 (25) 7 .1 (3) 29.9 (2) 2.5 (3) A 20. 3 (12) A 26.4 (30) K 10 . 9 ( 11) A 10.7 (19) A 5.9 (24) A 10.0 (16) D 3.5 (2) A 9.7 (2) G 1. 8 ( 2) B B A B B J J G c 7.6 (9) 7.1 (22) 5.8 (11) 4.8 (4) 2.8 (10) 2.5 (11) 2 . 6 (4) 2 .5 (4) l. 3 (28) K K c c J c A J B I I I i I LOWEST PLANT 7. 4 ( 5) 6.1 (14) 3. 7 (2) 3.2 (8) 2.0 (5) 1.1 (3) 1.3 (4) 0.2 (2) 0.1 (5) J G J G G E K E E TABLE XIII ASBESTOS CONCENTRATION* BY OPERATION FOR INSULATION WORKERS Marine Const ruction Repair No. of Samples Actua l Arithemetic Means Previous Recalculated Time-Weighted Mean*** Average*** Recalculated Time-Weighted Average*** Prefabrication Application Mixing General Tear Out Finishing Light and Heavy Industrial Construction Prefabrication Application Mixing General Tear Out Finishing 7 25 19 18 14 19 23 36 17 19 10 16 30.4 6.2 21. 2 0.6 31. 5 0.3 8.7 ) 2.6 ) 6.4 ) 0.6 8.3 ) 0.3 ) ) ) ) 9.2 ) ) ) 1.8 10.l 3.1 4. 7 1. 6 12.8 0.9 6.6 ) 2.4 ) 2.9 ) 1.1 ) 7. 1 ) 0.9 ) ) ) 4.2 ) ) ) ) 2.2 * Fibers/ml>~ in length ** *** Sumroarized from data Personal communication, March 1970 from Ba l zer & Cooper (4) TABLE XIV ASBESTOS CONCENTRATION BY OPERATION~, 1969 Average asbestos fiber levels Work practice ll Asbestos cement 02 Asbestos cement b3 Asbestos cement 14 Asbestos cement Cutting calcium sili- cate, block, pipe Dl Cutting calcium silicate, block & pipe D2 Cutting calcium sili- cate block & pipe Cutting calcium silicate block & pipe 64 Spraying insulation Environmental conditions High ceiling room. Louvre venting Personal Area Samples Samples Distance Fibers/ml Fibers/ml from Source 2.4 . 45 2 I Low ceiling room. Poor ventilation 2.6 Access tunnel Power house. Low Ceiling, poor ventilation Table and hand saws, in power house - open 6. 1 3.9 1. 2 2.5 3-5 I Same - in industrial 4.1 building. Good ventilation . Apartment house boiler ro om. 11.5 No ventilation. Work 3"-18" from breathing zone. Limited ventilation 9.4 1. 6 3-4' Turbines in power plant very high ceiling, good vent:ilation. 47 . 7 19.5 3' 28.0 6 1 Fibers/ml "'7 5p in length Notes: 1. Conditions usually l ocal ventilation; variable: Cement mixed composition of material dry may - applied wet; rapid changes in vary; number of men on job may 2. vary. Average of counts (excluding spray insulation ) : "'75 fibers / ml= 64.5%; 5-12 fibers/ml 25.5%; 712 fibers/ml m 10.0% . - (5) 3. Information prepared by Reitze, Nichols on, and Holaday. TABLE XV ASBESTOS PLANT Z - CEMENT PIPE PERSONAL SAMPLES - SECULAR TRENDS MEANS BY OPERATION AND SAMPLE SIZE OPERATION MEAN 1967 No. OF SAMPLES MEAN 1971 NO. OF SAMPLES Warehousing & Mixing Pip- Forming Curing Pipe Finishing Coupling Finishing Epoxy Packing Miscellaneous 6.2 2. 1 1. 3 5.0 12 . 8 2.6 1. 7 4 15 8 6 9 2 6 2. 3 2 1.8 4 0.4 4 1. 7 10 5.3 7 0.9 5 1.1 7 0.5 9 1 - All samples expressed as fibers~ Sp i ce by the standard method recommended in this document . 2 - Information prepared from NIOSH data. TABLE XVI ASBESTOS PLANT S - FRICTION PERSONAL SAMPLES - SECULAR TRENDS MEANS BY OPERATION WITII SAMPLE SIZE OPERATION 1966 NO. OF MEAN SAMPLES 1969 NO. OF MEAN SAMPLES Mixing, Coating & Extruding Forming Hot Pressing Baking Grinding & Sanding Cutting & Drilling 7.5 5.7 13.1 9.1 10.8 11.0 24 7 15 1 34 31 8.0 6 0.5 3 1. 8 3 2.6 4 4. 7 10 2.8 8 Bonding & Riveting Inspection & Packing Miscellaneous Friction 9.6 21 6.7 6 1.9 5 1. 8 10 1971 NO. OF MEAN SAMPLES 11.0 16 3.6 4 4.9 5 5.4 5 5.2 16 7. 7 22 5.1 4 1 - All samples expressed as fibers 775.Afcc by the Standard Method recolIIDended in this document. 2 - Information prepared from NIOSH data. OPERATION Warehousing Mixing Forming Curing Finishing Packing Miscellaneous TABLE XVII _,gESTOS CEMENT SHINGLE, MIU.BOARD AND GASKET PERSONAL SAMPLES - SECULAR TRENDS MEANS BY OPERATION AND SAMPLE SIZE PLANT W 1967 NO. OF MEAN SAMPLES 1970 NO. OF MEAN SAMPLES 8.9 4 8.3 14 1.8 36 4.4 6 2. 6 3 0.4 1 4.3 35 2.5 22 2.3 13 1.5 7 0.7 2 1.2 2 1 - All samples expressed as fibers >5,l>J./cc by the Standard Method reco11111ended in this document. 2 - Information prepared from NIOSH data. OPERATION Mixing Forming Curing Finishing Inspection & Packing Miscellaneous Office Worker TABLE XVIII ASBESTOS, INSULATION PLANT X PERSONAL SAMPLES - SECULAR TRENDS THERMAL PIPE MEANS BY OPERATION 'WITH SAMPLE SIZE 1967 NO. OF MEAN SAMPLES 1970 NO. OF MEAN SAMPLES 163.0 33.3 5 18 36.2 25.7 3 3 2.5 1 31.0 1 44.6 3 34. 8 4 16.7 7 17.9 3 13.8 2 1971 NO. OF MEAN SAMPLES 74.4 11 50.6 39 14 . 4 5 39.5 26 22.8 15 16.6 24 1 - All samples expressed as fibers 75_,u/cc by the Standard Method recommended in this document. 2 - Information prepared from NIOSH data. OPERATION Mixing Forming Curing finishing Inspection & Packing Miscellaneous TABLE XIX ASBESTOS, INSULATION PLANT Y PERSONAL SAMPLES - SECULAR TRENDS THERMAL PIPE MEANS BY OPERATION WITH SAMPLE SIZE 1967 NO. OF MEAN SAMPLES 1970 NO. OF MEAN SAMPLES 107 .0 3 27 .7 2 98 . 9 12 24.1 13 32.2 13.3 4 2 16.8 13.0 21.0 2 8 14 1971 NO. OF MEAN SAMPLES 46.3 7 25.2 32 15.0 11.0 2.7 17 19 5 1 - All samples expressed a.s fibers >5 ,Jee by the Standard Methocl recommended in this document. 2 - Information prepared from NIOSH data. OPERATION Fiber preparation Carding Spinning Twisting Winding Weaving Rope, Wick, Braid & Cord Finishing Miscellaneous TABLE XX ASBESTOS TEXTILE PLANT A PERSONAL SAMPLES - SECULAR TRENDS MF.ANS BY OPERATION 'WITH SAMPLE SIZE 1964 NO. OF MEAN SAMPLES 13.6 6 1966 NO. OF MF.AN SAMPLES 9.6 4 14.5 4 52.2 7 11. 8 5.4 2 7 15.3 9.2 9 8 9.5 5 5.6 11 13.8 17.7 4 15 0.2 6 6.9 2 5.7 2 7.5 1 1970 NO. OF MEAN SAMPLES 22.3 4 27.3 10 10.9 11 14.5 7 9.7 12 12.4 25 2.6 4 29.9 2 1 - All samples expressed as fibers ~5 ,,uJ cc by the Standard Method recommended in this document. 2 - Information prepared from NIOSH data. OPERATION Fiber preparation Carding Spinning Twisting Winding Weaving Rope, Wick, Braid & Cord Miscellaneous TABLE XXI ASBESTOS TEXTILE PLANT J PERSONAL SAMPLES - SECULAR TRENDS MEANS BY OPERATION WITH SAMPLE SIZE 1965 NO. OF MEAN SAMPLES 1967 NO. OF MEAN SA.'1PLES 6.4 7 15.7 5 8.1 17 7.9 14 12.6 27.4 11 11 7.3 20 17.7 3.4 9 .., .) 5.6 47 6.8 12 1971 NO . OF MEAN SAMPLES 7.4 5 7 . 8 40 3.7 2 6.9 35 2.8 10 10.0 16 3.5 2 2.5 4 1 - All samples expressed as fibers >5 ,Ice by the Standard Method recommended in this document. 2 - Information prepared from NIOSH data. OPERATION Varehouaing & Mixing Pipe Pond.ng Curing Pipe Finishing Coupling Finishing Epoxy Packing Miscellane ous - Not Applicable PLANT N % 2 % !I % 10 25 100 100 (4) JJ 100 100 (3) 100 100 100 (3) 100 100 100 (6) 100 100 100 (4) 0 100 100 (l) 100 100 100 (4) --- TABLE llll ASBESTOS c:xMDfT PIPE PE'8.CENT OP 5 J'IBERS /CC SAMPLES LESS TB.AN OR EQUAL TO AND 10 l"lBOS /CC LCltCEll TlWI 2 5u YIBEltS / CC, I1' LENbl'H, BY. 1'LANT AN1> OPEaAl'lON ( ) NO. 01" SA>IPU:S REPllESE!fl'S l"IBE'RS LOllGlll THAN 5u PLAN'T 0 t 2 %_5 t 10 o 0 100 ( 2) JJ 100 100 ( 6) 67 100 100 (3) 100 100 100 ( 4) 25 50 100 ( 4) 100 100 100 (1) 100 100 100 (l) --- PI..Aln' p % 2 % 5 %_10 100 100 100 (J) 100 100 100 (4) 100 100 100 ( 6) 100 100 100 ( 6) 100 100 100 (16) 100 100 100 (6) - -- 100 100 100 (9) PI..Aln' Q % 2 % !I % 10 100 100 100 (4) 100 100 100 ( 2) 100 100 100 (1) 80 100 100 (5) 80 100 100 (5) -- - 0 0 100 (1) 100 100 100 (3) PLANT Z %_ 2 % 5 % 10 50 100 100 (2) 75 100 100 (4) 100 (' 100 100 (4) 70 100 100 ( 10) 43 57 (7) 71 l:>O 100 100 (5) 86 100 100 (7) 100 100 100 (9) I I PLANT AA % 2 %_!1 % 10 PLANT 118 % 2 %_5 % 10 100 100 100 ( 5) 100 100 100 (6) 100 100 100 ( 5) 100 100 100 (9) 100 100 100 (21) 100 100 100 ( 1) 100 100 100 (13) 100 100 100 (8) 80 100 100 (5) 100 100 100 (10) 93 100 100 (15) 100 100 100 (9) 90 100 100 (10) 83 100 100 (6) 100 100 100 (6) 100 100 100 (6) OPERATION PLANT H %~2 %_i5 %_il0 Mixing, Coating 6 Extruding 0 50 (2) 100 Forming 100 100 (6) 100 Hot Pressing 100 100 (7) 100 Baking 100 100 (2) 100 Grinding 6 Sandi~ 90 100 100 (10) Cutting & Drilling 50 75 (12) 83 Bonding & Riveting 75 75 (4) 100 Inspecting & Packing 54 69 100 (13) Miscellaneous 67 78 (9) 100 - Not applicable TABLE XXIII ASBESTOS FRICTION PLANTS PERCENT OF SAMPLES LESS 5 FIBERS/CC, AND 10 THAN OR EQUAL TO FIBERS/CC LONGER : FIBERS/CC, TRAN ~ BY PLANT AND OPERATION ( ) NUMBER OF SAMPLES Pl.ANT H %_$.2 %_s.5 %_!10 71 86 (7) 100 PLANT S ~2 %_s:5 't~lO 13 19 (16) 44 PLANT T %<2 %<.5 %.sJ.O -- - -- - 50 100 (4) 100 75 75 (4) 0 40 (5) 100 100 100 100 100 (2) - -- 100 100 (2) 100 0 40 (5) 100 100 100 100 (2) 57 86 (7) 100 13 56 (16) 94 88 88 (8) 88 100 100 (7) 100 100 (1) 100 100 5 32 (22) -- 64 - 86 100 100 (7) 100 100 100 (l) 100 100 (4) 100 100 (1) 100 100 50 50 (4) -- 75 - 86 100 100 (7) 100 100 100 (5) I I I I PLANT U %~2 %9 %,90 0 50 (2) 100 67 67 67 (3) 100 100 100 (2) 0 100 100 (1) 0 25 100 (4) 00 (l) 0 0 67 100 (3) 100 100 100 (3) TABLE XXIV PERCEA5NSTBFEIBOSTEFORSSSA/CMCECPML, EESANNTLDESHS1S0IN!GFHILABENE,RMOSR/ICLCLEBQOULOAANLimGTEOARNDT2HAFGNIABSEK5ERpTS/CC, BY PLANT AND OPERATION ( ) NUMBER OF SAMPLES OPERATION Warehousing PLANT R %<2 %~ %<10 100 100 100 (3) Mixing Forarlng Curing Finishing Packing Miscellaneous 53 67 93 (15) 83 94 100 (18) 50 100 100 ( 2) 71 94 100 (17) 75 100 100 (4) 100 100 100 (4) - Not Applicable PLANT U %~2 % %_90 100 100 100 (1) 67 100 100 (3) 100 100 100 (6) 100 100 100 (2) 86 100 100 (7) 100 100 100 (2) 100 100 100 (1) PLANT \I %_{2 %~ x90 50 67 100 (6) 33 100 100 (3) 100 100 100 (1) 71 100 100 (7) 100 100 100 ( 2) 100 100 100 (2) OPERATION Kll:ing Foraing Curing Finuhina Inapection & Packing Mi.9ce.ll.aneoua TABLE XXV PERCE5NTFIBOEFRSSA/CAMCSP(BLB, EYESSA)TNPOLLDASESN1NSIT0UNMSTFABIHINJEBLADRAENRTOOIOSPFOR/ECNRSCEAAQPMTLULIPAOAOLNNLNETGSTSEOR 2 FIBERS/CC, TRAN ~ PUNT R %_i2 %~ %_5.10 57 71 (7) 86 90 90 100 (10) -- - 82 100 100 (11) 100 100 (1) -- 100 - PLANT X %_f2 %<5 %<10 00 (11) 00 (39) 00 (5) 8 12 (26) 18 15 40 15 13 27 (15) 21 46 (24) 40 54 PLANT Y %~2 ~5 %<l.O 00 (7) 0 0 9 13 (32} -- - 6 6 29 (17) 0 16 63 (19) 40 100 100 (5) PLANT CC %_i2 %~5 %9-0 100 100 (2) 100 100 (7) 100 100 (1) 100 100 (4) 100 100 100 100 100 100 (11) 100 100 (4) 100 100 I PUJ'IT DD %<"2 %9 %<10 67 67 (3) 100 100 (5) 100 100 (1) 40 100 (5) 67 100 100 100 63 100 (8) 50 100 (4) 100 100 - Not applic.able TABLl. XXVl ASBESTOS PERCENT OF SAMPLES Ll.SS 5 PTBERS/CC. , AND JO BY PLANT TEXTILE Pt.OITS Tl\A~ OR EQUAL TO P!BP.RS/CC LONGER AND OPf.JlATIO~ 2 FIBERS/CC, TRAN 5u ( ) NUMBER OF SAMPLES OPDATIOfl PLANT A %2 %5 Fiber PYeparation 00 ( 4) %_10 25 Carding 00 (10) 10 Spinnin& 09 (11) 36 TV1.t1q 00 (7) 29 Viodiuc 8 33 (12) 50 11...-..in& 4 16 (25) 44 Rope, Vick, Braid & Cord 50 75 (4) Hicellaneoua rinilhin& 00 ( 2) -- 100 0 - Pl.AliT 8 %_2 %_5 %_10 0 17 (12) 58 07 (30) 40 5 26 (43) 77 0 11 (19) 58 25 54 (24) 83 16 58 (57) 86 PLANT C % 2 I 5 %_10 0 0 33 (3) 0 0 75 (4) 0 36 91 (11) 0 75 100 (4) 0 60 100 ( 5) 36 100 100 (11) PLANT D %_2 %_5 %_10 0 0 33 (3) 20 40 60 (10) 0 13 44 (16) 13 50 75 (8) 43 71 86 (7) 8 33 88 (24) -40 100 100 - - 33 33 33 (3) (5) - --33 67 100 0 50 83 (6) (3) -82 100 100 (28) 50 100 (2) 100 - - PLANT E % 2 %_5 %_10 ----- -- - --- --- 67 100 100 (3) --- 100 100 100 (2) 100 100 100 (5) I P'l.ANT c; %_2 %_5 %_10 00 (2) 50 Pt..ANT J %_2 %_5 20 40 (5) %.,.10 80 14 57 (14) 71 13 38 (40) 80 0 33 (6) 100 0 100 (2) 100 38 75 (8) 100 6 26 (35) 89 m60 100 100 40 90 100 (10) 8 50 100 (12) 0 25 ( 16) 56 -- - 0 100 (2) 100 0 50 ()) 50 50 100 100 (4) -67 67 100 - - (2) I PLANT J: -%_2 %_5 % 10 22 44 (9) 67 23 )6 (22) 77 3 14 (36) 42 25 38 (8) 50 40 53 (40) 78 26 76 (50) 96 75 100 ( 4) 100 80 91 100 (45) 63 100 (8) 94 - !lot ~lie.able TABLE XXVII Duration of Asbestos and of Asbestos Insulation F 1945 aietsachmnteidopnlrodyeye2x,mv3a2emeelmnioetnppmelmapdonlyedoenindytkenoes1oosf9wm6nXo9eft--eir1mxaa9ypne7o0Afsi.inusnrbde1ei9snt4togo1ss- X-RAY ASBESTOSIS DURATION OF EMPLOYMENT TOTAL 0 + l+ 2+ l DAY OR 7 3 0 4 0 LESS 1 - 7 DAYS 13 4 3 51 l - 4 WKS 15 5 3 61 l - 3 ms 35 6 5 23 1 3 - 6 MOS 35 8 3 19 5 6 - 12 z.tJS 31 5 3 15 5 1 - 2 YRS 48 7 5 25 8 2 - 5 YRS 36 3 8 16 6 5 - 14 YRS 12 232 1 0 54 A"ENLNLOGNIENEME" EPLR(OOINYFGEFEICSAENID)NCTSLHHURIODPUEPGDINH. GT,EHXATPOTOSTOUHFRAEMTSAONVFAAGPRERIMEOEDDNUTFC,RTOIMON EMPLOYEES. 1 - Personal Communication Dr. Irving Selikoff, January, 1971. 3+ 0 0 0 0 0 3 3 3 2 TABLE XXVIII Lapsed period from onset of exposure in 344 deaths among employees of an asbestos insulation factory, employed at some time in 1941-1945 and followed to 1970. Cause of Death Lung canc er Mesothelioma G. I. cancer Asbestosis All other cancer All other causes TOTAL 0-4 0 0 1 0 1 26 28 Years from Onset 5-9 10-14 15-19 20-24 3 8 14 00 0 16 2 16 3 4 21 8 8 39 7 6 28 30 52 42 37 54 84 78 25+ 18 2 3 5 5 30 63 TOTAL 59 4 18 24 31 208 344 1 - Personal communication Dr. Irving Selikoff, January, 1971. TABLE XXIX ASBESSUTMOMS AARYNDOSFUB4SECQAUSEENTHISDTEOVERLIEOSPMEONFTEXOPFOSMUERSEOTTHOELIOMA Race Sex w ww M FM w F OccuEational Histor~ Before asbestos exposure Asbestos exEosure Duration of exposure Type of Work None Unknovn Engineer Student 6 weeks Pipe Insulation None 3 years Neighborhood exposure None Unknown - at least several yrs Family exposure After asbestos exposure Unknown Housewife Bookkeeper-fl oo manager Housewife Type of asbestos Respirator protection ChrysotUeamositecrocidolite None Chrysotileamosite None Chrysotileamosi te NA Amosite NA Mesothelioma History Age at death Site Histological diagnosis 74 41 Peritoneal & Pleural Biphasic Right Pleural (Biphasic) epithelial & fibrou 30 Pleural Biphasic Pleomorphic 52 .Left Pleural - Lapsed period since exposure Duration of illness Concurrent asbestosis Smoking history Duration of smoking history (years) 25 years 13 weeks Pleural Calcifica- tion 0 21 years 5 weeks rade I by X- Ray 19 years year None Unknown 2 years one by X-Ray 40 20 NA 24 5 years topped in 19 65 l - Personal communicatio Dr. I rving S ikoff - January , 971. !ABLE XXX ObMsPeaSrrivocneodtdeurnecaa,tnnidofconeEr aSxn2pe9der1vcMtiMecdaeailnDJetosSeebnatweatahnhnosadcnaeW!dr-hdSofrirezokoreervuddig1c~P4Me~6r4ciJomoerMbtmaasbraliieleletryynsdw3iRn1Rhao,etNit1Woio9rsnoe6-rd9kA(SesbdMDbyueRPsr'Csritnoi)amgsusaPe1r9riaol4nyd1du-1icDn9ti6uoA7ent,sbEaSenxhsdpotoovssinugre Cause of Death and In List Number Accumulative exposure to asbest ternationa Limited Ext>osure Obs. Ex-o. SMR os in Obs. million < 125 Exo. parts SMR per cubic foot 125-250 Obs. Exo. years SMR (mppcfyr) 250-500 Obs. P:rn. All Causes 114 129.9 87.8 365 344.8 105.8 162 139.8 115.9 184 156.7 All Cancer (140-205) Digestive System (150-159) 22 9 22.3 98.6 8.2 109.8 74 27 56.3 131.4* 23 21. 9 123.3 5 23.6 97.4 8.9 56.2 52 19 26.4 10.0 Lung, Bronchus, Trachea & Pleura (162-163) 8 4.8 166.7 18 10.7 168.2 11 4.9 224 . 5* 16 5.4 All Other Cancer 5 9.3 53.8 29 23.7 122.4 7 9.8 71.4 17 11.0 Cerebral Vascular Lesions 15 14.8 101.4 31 41.4 74.3 14 16.2 86.4 15 18.2 SMR 117.4* 197.1* 190.0* 296.3* 90.9 82.4 (330-334) All Heart Disease (400-443) Coronary Heart Disecse (420) All Other Heart Disease Diseases of the Respiratory System (470-527) Pneumoconiosis & Pulmonary Fibrosis (523-525) All Other Causes 46 60.8 75 .6 168 161.2 104.2 72 65.5 109.9 75 73.3 102.3 39 48.9 80.1 129 124.8 103.4 59 52.2 113.0 55 57.8 95.2 7 12.1 57.8 39 36.4 107.1 13 13.3 97.7 20 15.S 129 . 0 - - - -- -10 5 7.7 129.9 26 19.0 162.5* 11 80 137. 5 17 -8 3 8 8.9 191. O* - 22 24.5 89.8 66 66.6 99.1 42 26.5 158.5* 25 29.9 83.6 * SMR s Source: i gADnieSfCitcouudafynletolyfanddthiefVfieDvrioeasnnet-RHfeersnopmdoenr1sso0e0nRa(eUtlan5tp%iuobnlelsivhsheipeld. B~entwuesecnriAptsb)est os Dust and Lung Cancer by Philip Enterline, Pierre TABLE XXX (continued) Cauae of Death and International List NUD1ber 500-750 Obs. P.rn. SMR >750 Obs. E.lcll. SMR Oba. v.'"'. SMR All Causes A ll Cancer Digestive (140-205) System (1 50-159) Lung, Bronchus, Trachea & Pleura (162-163) 77 50.2 153.4* 34 18 8.7 206.9* 9 6 3.3 181.8 2 9 1.8 500.0 5 26.2 4.5 1.7 0.9 129.8 200.0 117.6 555.6 All Other Cancer Cerebral Vascular Lesions 3 3.6 83.3 2 5 5.6 89.3 3 1.9 105.3 3.0 100.0 (330- 334) All Heart Disease (400-443) Coronary Heart Disease (420) All Other Heart Disease Diseases of the Respiratory System (470-527) Pneumoconiosis & Pul.monary Fibrosis (523,525) All Other Causes 36 23.5 153 . 2* 11 24 13.8 127.6 8 12 4.7 255.3* 3 11 2.8 392.8* 9 8- -5 12.3 9.9 2.4 1.5 - 89.4 80.8 125.0 600.0* - 7 9.6 72.9 2 4.9 40.8 *SMR significantly different from 100 at 5% level. Oba. Exl>. SMR I I I I U U ~ CCV(UMUIT,1HTlHC;OlllC.C.1)1'- 7)7 .. 1 )2.