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ic H'-i. Assoc J -i i ^ ; i > Nsfri . '<va C ummings Avard Lecture) Asbestos and Disease: An Industrial Hygienist's Perspective MORTON CORN. Ph D . CSP ''roievvor and Director. Division ol Environmental Health Engineering. School of Hvgiene and Public Health. Johns Hopkins l niversity. 615 North Wolfe Street, Baltimore. MD 21205 plaintiffs exhibit oduction :s not personally acquainted with Donald Cummings. I know of him. At the Harvard School of Public Health ie mid-1950's he was occasionally referred to as part of umous Saranac Laboratory team consisting of Leroy dner. Homer Sampson and DonCummings. Cummings - the hygienist, a man exhibiting professional compe.c. curiosity and energy relative to investigation of the t silicosis tuberculosis interaction. He was said to have ; an abiding belief in ourcapacity to unravel this complex logical interaction, as well as other pneumocomotic dis cs of our industrial society. His tragic and untimely death CEL-1157 in an airplane crash in 1942 curtailed the life of a man who. by all accounts, had his major scientific and professional contributions ahead of him. It is a privilege and an honor to be selected .to deliver this address honoring Donald Cummings. The subject of this lecture is an industrial hygienist's per spective on asbestos, and United States approaches to reduc ing the risk of disease to those inhaling this extraordinary material. Asbestos has probably received more attention in the United States and worldwide than any other potentially toxic agent addressed by practitioners and investigators in the fields of industrial hygiene, occupational medicine. Dr. Morton Corn, Ph.D., CIH, curitiy is Professor and Director of the Ivision of Environmental Health tgineering, School of Hygiene and iblic Health at The Johns Hopkins niversity, where he has been a faculty ember since 1980. Prior to his appointment at Johns lopkins. Dr. Corn advanced through ie ranks from assistant to full professor v hile on the faculties of the Graduate vchool of Public Health and the Depart ment of Chemical Engineering at the I niversity of Pittsburgh (1962-1979). A leave of absence from 1975 to 1977 pres ented him the opportunity to serve under President Ford as Assistant Secretary of Labor for Occupational Safety and Health in the United States Department of Labor. While obtaining his undergraduate degree in Chemical Engineering from Cooper School of Chemical Engineer ing Dr. Corn worked summers as a Research Assistant for the U.S. Atomic Energy Commission, thus beginning a career that has earned him numerous awards, fellowships and other honors. Beginning with the New York State Regents Scholarship, which he was awarded from 1951-1955, Dr. Corn has amassed a lifetime of achievements. including the National Science Founda tion Postdoctoral, the John Simon Guggenheim Fellowship, the USAEC Fellowship, awards for published works, and invitations as guest speaker and lec turer at conferences throughout the world. Dr. Corn also has served on various panels and committees, such as the Environmental Protection Agency Science Advisory Board (1977-1984) and the Office of Technology Assessment Committees on Control Technology in the Workplace and Hazardous Wastes. In 1981 Dr. Corn was elected Vice Chairman of the American Conference of Governmental Industrial Hygienists, succeeding to Chairman in 1983. In 1984 he was elected President of the Associa tion of Universities in Occupational Safety and Health. Dr. Corn currently chairs the Industrial Hygiene Commitee of the International Resource Center in Occupational Safety and Health; and is a member of NIOSH's Mine Health Research Advisory Committee. Among his other memberships. Dr. Corn also belongs to the American Association of University Professors; the awards committee of the ACGIH; the American Industrial Hygiene Asso ciation, as a member of the Manage ment Committee; the American Insti tute of Chemical Engineers, full grade; American Public Health Association; Air Pollution Control Association; Brit ish Occupational Hygiene Society: Society of Occupational and Environmental Health, founding member; and numer ous others. Dr. Corn's published works include papers, book chapters, and conference and symposia proceedings dealing with the subjects of aerosol physics, air pollu tion, industrial hygiene, safety in the workplace and public policy. *m Ina Hyl *ssx J 1*7) September 1936 515 occupational epidemiology and toxicology . One couid argue that more is known about the toxicity of asbestos and the dose-response curse lor its inhalation by those exposed than is known about any other industrial material. Asbestos has created economic crises in selected corporations responsible primarily for its production and product distribution, caus ing two major U.S. corporations to enter into Chapter 11 bankruptcy.'11 The concern for asbestos has spread from those exposed occupationally to those experiencing nonoccupational exposure. Asbestos has precipitated regulation of the nonoccupational environment by the Environmental Protection Agency and the Consumer Product Safety Commission in the United States. One could review our experience with the health effects of asbestos from the perspective of the lawyer; asbestos has set precedents in personal injury and property damage litiga tion. One could also view the asbestos experience as a case study in the evolving occupational and environmental medi cal literature, where scientific and technical precedents have been established. There are numerous facets to the asbestos story and one could select different vantage points to observe and evaluate those facets. 1 focus here on the indus trial hygienist perspective. What can we learn, as individuals and as a profession from this experience, this extraordinary case of societal utilization of a valuable material and the associated growing recognition of its disease potential? Background to the Occupational Standard My introduction to asbestos occurred in 19S5 as a graduate student in Industrial Hygiene at the Harvard School of Public Health. Our class studied the properties of dusts and fine particles in general, under the tutelage of Professors Leslie Silverman, Philip Drinker, and Charles Williams. In retrospect. 1 was instructed extremely well on the technical assessment of airborne concentrations of asbestos. At that time we evaluated asbestos dustiness according to the American Conference of Governmental Industrial Hygien ist's Threshold Limit Value (TLV) guideline of five million particles per cubic foot of air determined by light micros copy. Students were .instructed by Dr. \k....arr.s r. :r.e appropriate sample collection by midget impinge:. mde preparation, and microscopic counting procedures. Perhaps the first lesson to be derived from this experience was that we were not urged to critically evaluate the documentation of the TLV. The Dreesen study "1 of textile workers was the basis for the TLV guideline. It was an extremely limited cross sectional epidemiological investigation, characterized as follows in the first edition of the Documentation of Thresh old Limit Values, published by the ACGIH in 1962: "The present threshold limit relates to the prevention of asbestosis. It was recommended by Dreesen. et al,, after study of 541 employees m three asbestos textile plants using Chrvsotile. Only three doubtful cases of pneumoconiosis were found in those exposed to dust concentrations under 5 mppcf. whereas numerous well marked cases were found above 5 mppcf. Counts were from impinger-collected samples in ethyl alcohol and distilled water. Both fibrous and non-fibrous particles were counted, but the latter greatly predominated. While chemical analyses of collected samples of air borne dust corresponded to those of settled dust sam ples it is believed that dust counts of particulates by conventional methods can be expected to give only an indirect measure of the risk of asbestosis because of the great relative importance of long fibers."'3' The above was the total documentation for the guideline in 1962. In 1955 the brief discussion of asbestos disease found in the book Industrial Dust by Drinker and Hatch'41 was the major reading for graduate industrial hygiene stu dents on the rationale for the guideline. The TLV was for pure chrysolite fiber. In practice, U.S. industrial hygienists utilized the TLV for all situations where airborne asbestos was encountered. It was not until 1968 when the British Occupational Hygiene Society (BOHS) published their occupational hy giene standard for asbestos that a specific level of risk for basal rales and x-ray changes was offered for asbestosis."" 1 1938 1946 1970 1971 1971 1975 1976 1976 1983 1984 ACGIH OSHA NIOSH OSHA OSHA TABLE I U.S. Asbestos Standards" Million particle*/ per cubic ft. Fibrt/ cc STEL,* fibers/ cc Recommended Adopted Adopted Proposed Emergency Proposed Adopted Recommended ETS Proposed TLV TWA 5 5 2 - * - * 3cr' 30' 12A 5 2 0.5 2 0.1 05 0.4 or 0.2 10 5 10 0.5 'Short Term Exposure Limit. 'Approximate fiber equivalent. SIS Am in<j Hyg Assoc J (47) Seotemoer 1986 TABLE II Factors Included in EPA Exposure Assessment Algorithm ` Condition of material Water damage Exposed surface area Accessibility Activity and movement Air plenum or direct air stream Friability Asbestos contenti * * * * * * * * * * * * * i others instructed in industrial hygiene in the 1950's and Is were aware of the limitations of measurement tech nics for asbestos-in-air. but were not seriously concerned i the adequacy of the TLV and were not addressing the d for change. Had our instruction focused more heavily understanding the basis for the numbers in the TLV's, the .ertainties would probably have caused us great discom: and concern. The BOHS publication profoundly affected . manner in which 1 assessed asbestos-in-air in the field ing the late 1960's. 1 obtained midget impinger samples .he traditional L'.S. method, but also obtained simulcously collected membrane filter samples, expressing alts as both mppcf (U.S. method) and fibers/cc of Topriaie size (BOHS method). Of course, part of the growing concern of hygienists was :ne increasing rea.icar.on of the carcinogenic properties of inhaied asDestos. a ub:ect soberly addressed in the 1968 BOHS standard. Why is familiarity with the basis for a guideline and its weaknesses essential to the hygienist.' W hile the standard is a single number, the interpretation of air sampling results and the accompanying recommendations will inevitably be shaded by the hygienist's insight into the basis for the standard. Standards, as we often repeat, are not fine lines between acceptable and unacceptable conditionsfor risks). However, how we place the results in perspective for concerned clients will be a reflection of our own awareness of the "softness" or "hardness" of documentation supporting the guideline or standard. In the 1971 third edition of the Documentation of Thresh old Limit Values by the ACGIH there is a more critical paragraph on the Dreesen study, as well as a lengthier de scription of results relevant to a standard. The Dreesen study is further treated as follows:'81 "A conference on the biological effects of asbestos in 1965 called attention to the very real probability that the 5 mppcf limit recommended by Dreesen is inade quate to give complete working-lifetime protection against all forms of asbestos. Medical data on which, the limits had been based were inadequate; more than PRODUCTION PROCESS Figure i -- Conceptual model of the three zones of influence to control workplace hazards.0| ina Hvg Issoc J 1*7) September 1986 517 nalt or the asbestos workers studied were under 30 sears of age and thus pros ided an rnsuificient exposure time tor asbestosis to deselop. Of the 105 ssorkers exposed to less than 5 mppcf. 82 had worked less than 5 sears; 101 less than 10 sears; only 4 had more than 10 sears exposure. Sesen of 36 workers exposed to 5-9.9 mppcf had asbestosis; 3 of 50 workers exposed to 10-19.9 mppcf for less than 5 years had asbestosis. Vloreoser. it was a "point-in-ume" study; many of the ill were missing and the dead uncounted, hence not considered in the oxer-all evaluation of the limit." The recommended guideline based on the Dreesen study had stood for 33 years without critical reappraisal in the L'.S. until the 1965 New York Conference'" and the 1968 BOHS recommended standard prompted reappraisal. Let me be clear; I am not criticizing theTLV committee. The responsi bility for reexamination of the standard was and is that of practicing industrial hygienists; it is too important a matter to leave entirely to the toxicologists. Clearly, thefirst lesson ofthe asbestos storyfor industrial hygienists, particularly at a time when the field and this association is expanding to include industrial hygiene tech nicians. is that one must critically examine the supporting documentationfor a standard when utilizing it infield situa tions. Fortunately, the Occupational Safety and Health Act. with its requirements for adherence to the Administrative Procedures Act for standards promulgation, necessitates agency publication of a Proposal fora standard, followed by comments and in every case to date, a public hearing. These procedures should force currently practicing industrial hygienists to familiarize themselves with the uncertainties of permanent OSHA standards. The limitation of this proce dure for enforced learning is that OSHA has only passed 28 permanent health standards during its sixteen year history. The majority of standards in OSHA are still Permissible Exposure limits, as listed in Table Z-1 of the OSHA General Industry Standards.'8' They lack extensive documentation and associated engineering, medical, environmental, work practice and administrative controls. Thus, the burden remains on the hygienist to familiarize his/herself with the epidemiological and toxicological literature on which stan dards or guidelines are based. The passage of a new standard by OSHA will, of course, involve public review of the health related data base. How is the hygienist to integrate this type of knowledge into work and the discharge of his or her duties? The approach must be to indicate to a client and to those poten tially affected in the work environment the airborne stan dard involved, but to moderate this with full clarification of the uncertainties associated with the numerical values of permissible exposure time weighted average or peak values. The degree of concern of the industrial hygienist must be related to the relative uncertainties of the standard. It is only in this way that the practice of industrial hygiene will be a science and an art. and not a mindless application ol numbers and techniques. The Hazard Communication Standard of OSHA and state "right-to-know" laws should also serve to develop this approach. SIS Surrogate Measures of Exposure In addition to the basis for the asbestos standard, we snouid briefly address thesampling methodology forairborne liner concentrations. The early midget impinger mppct method ology involved counting all particles present, although there was good indication at the time of adoption that this surrogate for the active agent may not apply in env ironments where all materials processed or used were not asbestos. The heritage of adoption of this weak surrogate measure for fibers was felt throughout the 1960s. For example. I was involved as consultant to the Pittsburgh Corning Corpora tion and designed dust control systems for their Port Allegany, Pennsylvania and Tyler. Texas L nibestos plants. These facilities later became the subjects of major personal injury litigation; unfortunately, large numbers of people contracted asbestos disease at these sites. In both the Tyler and Port Allegany cases I reviewed reports of practicing hygienists prior to undertaking my own surveys and dust control systems design. [A dust control system was installed in Port Allegany. Pennsylvania but not in the Tyler. Texas plant. These cases can now be discussed because the litiga tion has been completed.'91] The hygienists had misinter preted the 5 mppcf guideline* and had counted fibers, instead of particles and fibers, w hile determining adherence to the mppcf standard. Because it was a mixed material environment, the fiber counts were low when compared to the standard, as one would expect. Therefore, startling con ditions of dustiness were encountered in Tyler, conditions addressed in previous hygienist reports and concluded to be in compliance with the 5 mppcf TLV for asbestos-in-air. The lesson suggested is that adoption ofa surrogate meas ure for extent of exposure to a toxic agent, although appropriate in an isolated or particular situation, may not be appropriate to many other situations. There must be an extraordinarily high level of care andforesight when a sur rogate in assessment is adopted. Indeed, we must as a profes sion take every precaution to make sure our members under stand the compromise inherent in the surrogate measure. Such a measure was adopted in the OSHA Coke Oven Standard. The benzene soluble organic portion of the res pirable dust was invoked as the surrogate measure for the risk of exposure to coke oven fumes, a very complex mixture of potentially toxic materials. In this case. OSHA proce dures. including public hearing and wide discussion of the strengths and weaknesses of the surrogate measure resulted in the compromise being widely understood. The current phase contrast microscopic method for examination of filter samples containing asbestos fibers does not measure asbes tos fibers exclusively, a result of technical imitations of the microscope illumination. In mixed material environments a very prudent measure of exposure is obtained. Unfortu nately. this is not well understood by many hygienists and the 2 f; cc OSHA standard is often thoughtlessly invoked in all environments. I will later return to the problems of a Because the plant was producing pipe insulation for the U S Navy, itwas covered by the Walsh-Healey Public Contracts Act: the mppcf TLV was an enforceable Federal Standard under this Act Am m<3 Hyg Assoc J (47) September. 1966 ^rrogate measure lor asbestos in regard to nonoccu pat tonal .-.posure to asbestos. I will not further dwell on the safety .ctor or lack of safety factor the use of surrogate measures ,-.a> include: my point is that those who use such surrogates ust very clearly understand what they are doing. nks to the Past ider present regulatory procedures in this country. OSH A rmanent health standards for airborne contaminants luire that an initial determination be made of the concenition of the agent in air. If the concentration is above a ggering permissible exposure limit, periodic surveillance indertaken. When the measurement technique and approach asbestos evaluation in the environment was altered and ,, membrane filter method introduced in the late 1960's, orts were not made to link this assessment methodology to st measurement techniques using the midget imptngerand . mppcf method. Today we are struggling with so called trospective industrial hygiene."110' In order to project the iuced impact of lowering standards for potentially toxic aterials. it is necessary to have fairly reliable dose-response rves based on past exposures and health effects unfortutely already experienced. There must be a period of simuineous env ironmental evaluation using new and old methodogies for assessment, with subsequent correlation of .suits. When we changed from the midget impinger mppcf . :hnique to the membrane filter phase contrast microscopy . chnique. there should have been a required period of dual easurement to permit conversion of old measurements to ,:e new framework. Such a required period could be part of ie regulatory requirements or could be voluntarily undertken by the industrial hygiene profession. We are now jessing at the conversion factors. 1 have personally simuited phased-out past production processes to perform simulmeous exposure measurements by these two measurements. Surely the lesson of this experience, so vividly illustrated uh asbestos where the projection offuture disease is so important,'111 is that as a profession we must take steps to insure simultaneous measurement by new and old techniques j hen an assessment methodology is changed. Non-Occupational Exposure to Asbestos Asbestos concerns spanned the years from the 1930's until the present lime. They overlapped the creation of the Occu pational Safety and Health Administration in 1970. One of the first issues addressed by OSHA was asbestos; in 1972 a permanent federal standard for asbestos was promulgated. Table 1 indicates the consistent lowering of the federal per missible exposure limits.'12' We are currently awaiting a further reduction in the federal standard. OSHA made it very clear to me and to other hygienists that the procedure up to that time of reporting our results to employers or clients exclusively, would not fulfill duties and responsibili ties assigned to us by law. We are in an entirely different phase of discharging our responsibilities by sharing informa tion. The implications of the Act for industrial hygienists was a subject that 1 addressed in 1976.IJI It remains a diffi cult subject area to sort out. Curreni na/aru :ommur..cat.on standards at the federal level and riant to know standards at the state levels are articulating the tv pes ot concerns t.nat we attempted to resolve as individuals or as groups ol profes sionals during the 1970's and early I980's. Needless to sav. the awareness of these responsibilities suggested there was justifiable concern and that there should be scrutiny of other areas of asbestos exposure, areas not covered by the Occupa tional Safety and Health Administration because they do not occur in places of employment involving exposures to employees. This category of concerns has been called nonoccupational exposure. The asbestos story provided evi dence that exposed workers could carry asbestos from the workplace to the home, thus causing exposure of those not employed. Awareness of this potential for contamination and the use ot asbestos in other environments has focused on asbestos in schools and buildings, an area addressed by the Environmental Protection Agency (EPA) under the Toxic Substances Control Act. It is an area engaged in complex property damage and third party personal injury litigation. The non-occupational asbestos exposure area also suggests certain lessons for the industrial hygienist; I'll now address several of these. Air Sampling for Asbestos in Nonoccupational Environments The EPA in a series of guidance documents often referred to as the Orange Book.114' the Blue Book,'15' and the Purple Book116' indicated early on that the agency had a very crystal lized view of the role of air sampling in evaluating the risk of exposure of building occupants to airborne asbestos. In the 1979 orange document the following statement is made in Chapter 7 on Exposure Assessment: "Air sampling is inappropriate to estimate asbestos contamination and exposure. In the school environ ment. it is virtually impossible to establish exposure potential using standard air sampling techniques."114' Instead of relying on the well-established science and art of air sampling. EPA adopted an algorithm, a device that could be viewed as a tool for qualitative risk assessment. The EPA offered a series of relevant environmental factors, listed in Table II. Numerical weighting factors were then assigned to each environmental factor and a formula was used to derive a numerical score for the given situation. Based on the algorithm score, the responsible party was directed to take immediate action (removal) or to postpone action. The environmental factors weighting was biased towards a resulting score which dictated immediate action, in most cases. What was not known by the professional community and the public in 1979 when EPA issued the first guidance document was that the algorithm had never been tested for its correlation with airborne asbestos concentra tions in different environments. Subsequently, two contrac tors to EPA indicated the poor correlation of the algorithm scores with airborne fiber measurements.11,101 The only highly consistent environmental factor was water damage to the material. Other investigations of algorithm validity -m ind Hyg teoc J (it) SepiemDef 1986 519 reached similar conclusions about the EPA algorithm usefulness. ,=" The need to correlate an algorithm with airborne fiber concentrations is essential if risk is to be estimated by a method other than measuring airborne concentrations. Fig ure 1 is a bedrock conceptual framework for exposure to environmental agents.'20' The mere presence of a source or agent is a potential hazard; the transmission of the agent to the receptor is necessary for a potential hazard to become a real hazard. Asbestos in a building is a potential hazard; asbestos-in-air concentration is the measure of that hazard being realized. The issuance of the 1979 guidance document by EPA in the absence of algorithm validation and in the presence of initial air sampling results discrediting the algo rithm. can only be viewed as agency arrogance bordering on "chutzpah."W1) In 1983 the "blue book" by EPA again discussed air sampling and the algorithm. It indicated that two of the eight factors assumed to correlate with measured levels of asbestosin-air did. indeed, do so. These were water damage and the proximity of the material to an airstream created by a venti lation system. A report to the EPA by Battelle Memorial Institute was the basis for the conclusions.1221 In spite of these findings regarding the lack of validation of the algorithm in terms of fiber-in-air concentrations. EPA in the blue book recommended use of six of the factors to predict "fiber release potential. "Once again, the agency recommended use of factors not validated by correlation with the property to be predicted, i.e.. fiber release potential, a term not well defined by the EPA to this day. What about measuring airborne asbestos in nonoccupational environments? In the blue book of 1983.115' EPA states the following in Section 3.2.3.: "Another proposed approach to assessing the need for corrective action is to measure asbestos fibers in the air. At best, this approach provides information only on current asbestos contamination and no information about the potential for fiber release and future air levels. Moreover, the use of air monitoring as an assessment tool involves substantial technical and economic problems which limit its use even for deter mining current levels of contamination." After devoting two additional paragraphs to the limita tions of air sampling, the following sentence concludes the air sampling discussion: "Given the limitations, EPA does not recommend the use of air monitoring for assessment purposes at this time." In the latest "purple book,""6' EPA stales that it does not recommend air monitoring "as a primary assessment tool at this time." Algorithm factors are still endorsed, but with qualitative scores only. Air sampling is recommended for post abatement evaluation. 520 W'hv have I dwelled on this EPA jboestos storv ' The lesson to the industrial hygiene profession is that we must always be alert and respond to obviously incorrect evaluations of some of the principal scientific tools of our profession. Our associations did not challenge the EPA in its denigration of air sampling. Much to my dismay, some hygienists have appeared in court on behalf of plaintiffs to reiterate EPA's downgrading of air sampling as a scientific tool. It eludes me as to how these individuals can. on the one hand, repeat the EPA position and then on the other hand, proceed in their daily utilization of air sampling methods for assessment of airborne hazards in a large variety of other environments. What is unique about asbestos in indoor environments? Risk Assessment in Nonoccupational Environments Another lesson stemmingfrom shift ofconcernfor asbestos in the workplace to asbestos in the nonoccupational setting is that this transition will occur with other potentially toxic agents. We must be prepared to place nonoccupational risks to potentially toxic agents in perspective with regard to other risks to life and health in the nonoccupational setting, utiliz ing the best techniques available. Risk assessment is cer tainly not an exact science, but in its present state of devel opment it is a valuable input to the assessment of health hazards, as stated by the National Academy of Sciences.123' Risk assessment highlights relevant factors related to the risk under scrutiny and it often permits scientific assump tions, or "inference guidelines"123' to be made in order to estimate the risk quantitatively. If hygienists abandon these matters of risk assessment, others may lose sight of the health component of the dialogue. The current situation with regard to asbestos risk in non-occupational settings is a mess because EPA has never addressed the magnitude of the risks involved. Table 111 displays the ranges of airborne con centrations of asbestos in non-occupational settings in build ings and schools. The lifetime risks associated with non occupational exposure to occupants of buildings and schools have been estimated by the National Academy of Sciences,124' by a Royal Commission of the Province of Ontario. Canada,125' and most recently by Hughes and Weill.'26' Table IV indi cates lifetime deaths per million exposed attributable to six years of asbestos exposure in schools. The exposure concen trations assumed are reasonable based on Table 111 data. In my opinion, the model used for Table IV is a defensible one, but you must refer to the original article to follow its devel opment. Hughes and Weill compared these risks to other commonplace risks in life. The upper estimate of approxi mately fifteen lifetime excess deaths (mixed fibers at 0.003 f/cc) would constitute an average annual rate of approxi mately 0.25 deaths per million exposed. The latter rate com pares with approximately 1200 deaths for long-term smok ing, 15 for bicycling, 15 for ingestion/ inhalation of foreign objects and 10 from playing high school football. The upper estimate of an average annual rate of 0.25 deaths per million exposed would be equivalent to 0.75 annual U.S. deaths, based on EPA's estimate of 3 million students currently exposed.126' Am. Ind Hyg 4oc. J (47) September 1986 fnstclearance Standard After Removal . r.e least defensible and perhaps strangest aspect of the jrrent I S. approach to non-occupational asbestos, is the .ndard for a clearance concentration for asbestos-in-air .lowing a major abatement activity. Three states, i.e. 1 .issachusetts. New Jersey and Rhode Island, have adopted mdards of 0.01 f cc after "aggressive sampling." Air samvs are evaluated by the PCM. or NIOSH method. A brief lew ofTabie 111 will reveal that before removal of asbestos the building air concentrations were, on the average, at stan order of magnitude less than the clearance concentran in the majority of buildings. The justification for the mdard is apparently that, because samples are collected er "agressive" sampling and because evaluation by the M method results in all fibers of a certain size being anted, life 0.01 ficc standard actually represents an oestos-in-air concentration far below 0.01 ii cc. This could , could not be a valid rationale; data have not been col-ted to accept or reject it. Of course, the clearance standard could well be a license to rmit building contamination to increase, resulting in ore airborne asbestos fibers after removal than before. I ; already aware of such cases, but data have not been >tematically collected. The clearance standard is a so-called concession to "praccaluy." Post removal air evaluation by electron microsipy has not been deemed feasible. PCM is rapid and would crmit efficient conclusion of the removal contract and .lease of contractors. However, the risk to building occuants from inhalation of asbestos could well be greater after .moval than before removal, when the original risk was premablv judged sufficiently compelling to trigger removal! The iliogic of this aspect of non-occupationa. ,j asbestos is sobering if one considers the large expenditures of effort and money which may increase, rather than decrease occupant risk to asbestos disease. 1 question the conclusion that electron microscopy is not feasible for postclearance evaluation of air samples. Indeed, in my opinion it is the only way to certify an abatement effort as satisfactory. The standard should be that post clearance air concentrations are. on a statistically valid basis, lower than preabatement concentrations. If they are not. contractors should clean the premises until they are. What can we conclude from thejuxtaposition of theabove estimates of risk from nonoccupational exposure to asbes tos. the manner in which EPA has proceeded to regulate this risk and the current level of public concern for this potential hazard? Obviously, those responsible for national regula tory policy have lost sight not only of some well established principles of environmental assessment, but of comparative or relative risks and the setting of priorities. Today, members of the public need only learn of the presence of asbestos in a building and they want it removed. This attitude can be traced to the manner in which EPA presented the subject; it failed to relate the asbestos risk to other environmental risks. It is still not too late for our professional associations to issue a scientific document, albeit abbreviated, which states our position on these matters. Such a document would not be responsive to immediately pending specific regulation; there fore. the urgency with which this must be done is not great. We can utilize a democratic form of assessing membership input to reach a position on the value of industrial hygiene tools in assessing the risk and the value of risk assessment in comparative risk delineation re\ asbestos in non-occupational environments. m nd Hyg Jssoc J 147) TABLE III Summary of Asbestos Exposure Samples In Different Environments'^'* Sample Set No. of Samples Measured Concentration ng/mJ Median 90th Percentile Equivalent Concentration (llbers/cc)** Median 90th Percentile Air of 48 U.S. cities Air in U.S. Schoolrooms without asbestos Air in Paris Buildings with asbestos surfaces Air in U.S. Buildings with cementitous asbestos Air in U.S. buildings with friable asbestos 187 31 135 28 54 1.6 16.3 1.8 7.9 19.2 6.8 0.00005 0.00023 72.7 0.00054 0.00242 32.2 0.00006 0.00107 19.1 0 00026 0 00064 96.2 0.00064 0.00321 'Table ill does not include all references and associated results, as contained in the more extensive NAS table."" "Based on conversion factor of 30^9'TM' = 1 fiber/cc. September 1986 521 TABLE IV Estimated Number of Lifetime Deaths Attributable to 6 Yr of Asbestos Exposure in Schools (Per 10 Exposed) By Fiber Type and Average Concentration ~ * Lung Cancer' Mesotheliomat Total 0 001 free Mixed fibers Chrysotile only 0.003 free Mixed fibers Chrysotile only 0.6 (0.3 to 1.2) 0.6 (0.3 to 1.2) 1.9 (0.9 to 3.7) 1.9 (0.9 to 3.7) 44 (2.2 to 8 8) 09 (0.4 to 1.8) 5.0 (2.5lo 10.0) 15 (0.7 to 3.0) 13.2 (6.6 to 26.4) 2.6 (13 to 5.3) 15.1 (7.5 to 30.1) 4.5 (2.2 to 9 0) 'Refer to original article for model assumptions rb: calculation of table entries. The tripartite descriptor of industrial hygiene has been recognition, evaluation and control. The movement of asbestos concerns from the workplace into the non-occupational environment suggests that we should add "anticipa tion " to these valuable descriptors of our activities. Antici pation. recognition, evaluation and control should be the future guiding lights of the field. Recently, EPA issued a proposal to sequentially ban asbestos usage in the United States.'271 Asbestos is a unique and valuable material. Can it be used in certain unique applications at an acceptable level of risk? That is an issue on which we as a profession should sort out our views and make them known. Safety is a relative term; it is acceptable risk.'28' The tools of engineering controls, combined with work prac tices and personal protective equipment usage can reduce the risk of using potentially toxic materials to a level com parable to other commonplace risks in life. Should we ban a material from usage if it is not a trivial material with numer ous substitutes? Asbestos is not in the latter category. The setting of a sequential asbestos ban leading to a total ban will establish a precedent that we, as industrial hygienists, should address publicly as a profession after crystallizing our viewpoint. Summary I have traced a personal thirty year journey of involvement with asbestos in the workplace and the nonoccupational environment, one still in progress, in an attempt to extract selected lessons for the industrial hygienist. Lessons for other professions, namely medicine, law and management have been studiously avoided in the interests of the scope of this presentation and permissible time. There are certainly numerous other lessons to contemplate. The movement of asbestos from the occupational to the nonoccupational environment is a case study that will undoubtedly be fol lowed in the future by other potentially toxic materials. We must determine our position as a profession with regard to the tools we utilize, the procedures we follow, and our understanding of our moral and legal obligations to prepare 522 tor the oiten scientifically and technical ar^ccrortarve positions assumed by others, including governmental agen cies, in their zeal to bring about change. We must discourage the opportunistic distortion of professional practices :n these matters, and must issue well considered statements as a profession, statements relevant to the way these matters are addressed by society. We have a responsibility to lend per spective to these issues, to not permit understandably emo tional responses to documented past severe health effects in other areas, such as the case of asbestos in the workplace, to carry over into conditions of very low exposures in the public domain. We must remind people of the relevance of dose-response and toxicological principles to assessment of risk. These principles are very much in the professional tradition of Donald Cummings. Perhaps that is what this address is really about, namely a reiteration of principles and an appeal, that as a profession we reassert these principles in order to discourage and thwart their distortion in the marketplace. References 1. Brodeur, P.: Outrageous Misconduct. New York: Pantheon Books. 1985. 2. Dreesen, W.C., J.W. DallaValle. T.l. Edwards, J.W. Miller and R.R. Sayers: A Study of Asbestos in the Asbestos Tex tile Industry. Pub. Hlth. Bull. No. 241. Washington. D C.: U.S. Pub. Hlth. Service. 1938. 3. American Conference of Governmental Industrial Hygien ists: Documentation of Threshold Limit Values. Cinofnnati, Ohio: ACGIH, 1962. pp. 11-12. 4. Drinker, P. and T. Hatch: Industrial Dust. 3rd Ed. New York: McGraw-Hill Book Co., 1959. pp. 45-46. 5. Hygiene Standards for Chrysotile Asbestos Dust. Comm, on Hygiene Standards, British Occupational Hygiene Soci ety. Ann. Occup. Hyg. 11:47-69 (1968). 6. American Conference of Governmental Industrial Hygienista: Documentation of Threshold Limit Values. 3rd Ed. Cincinnati. Ohio: ACGIH. 1971. pp. 17-19. 7. Whipple, H.E. (Ed.): Biological Effects of Asbestos. Ann. N. Y. Acad. Set. 132:1-766 (1965). 8. General Industry. OSHA Safety and Health Standards. 29CFR1910 1000, Table 2-1. OSHA U.S. DOL. Washington. D.C. 9. Com, M.: Depositions in H. Yandle, ef al. v. PPG Industries Inc., ef al. Civ. No. TY-74-3-CA, U.S. District Court for Eastern District of Texas. Tyler Oiv., taken in Washington, D.C., Sept. 21,1976; and A. Barber eta/, v. United States of America C.V. No. 80-321. U.S. District Court for Western District of Pennsylvania, taken in Baltimore, MD. Dec. 1-2, 1983. 10. Esman, N.A.: Retrospective Industrial Hygiene Surveys. Am. Ind. Hyg. Assoc. J. 40:58-65 (1979). 11. Walker, A.M., J.E. Loughlin, E.R. Friedlander, K.J. Rothman and N.A. Dreyer Projections of Asbestos-Related Disease 1980-2009. J. Occ. Med. 25.409-425 (1983). 12. Com, J.K. and M. Com: The History and Accomplishments of the Occupational Safety and Health Administration in Reducing Cancer Risks. Ch. 9 in Reducing the Carcino genic Risks in Industry, edited by P.F. Deisler. New York: Marcel Dekker, 1984. pp. 175-195. 13. Corn, M.: Influence of Legal Standards on the Practice of Industrial Hygiene. Am. ,,id. Hyg. Assoc. J. 37:353-356 (1976). 14. Asbestos-Containing Materials in School Buildings: A Guid ance Document. Part 1: U.S. Environmental Protection Am ind Hyg Assoc J (4?) Seofemoer 1986 strenuous action to eliminate possible asbestos sources. In these cases, it is important to communicate with the people involved and tell them what is happening and what is going to happen during the cleanup effort. Calling in a communications expert is often advisable." Before any asbestos abatement work is done, the plant should conduct a complete survey. According to an as bestos abatement contractor, Dwight Hopkins of Cross Construction Co.. Jacksonville, FL. plant workers often tear into asbestos-laden areas and cre ate contamination before they realize they should have evaluated the entire project in advance. One company, he notes, started to clean up an old boiler and realized too late that the duct work was also a source of contamination. More communication on the subject is needed. Unfortunately, not a great deal of information exists about the asbestos problem in industrial plants, or on abatement and control methods. Use of the material in industry was similar to that in other facilities. It was applied as insulation on hot or cold water pipes, ducts, boilers, and tanks. It can be found almost anywhere: in kilns in a glass plant, between the corrugated siding and the outer covering on an old building, in gaskets, and in fireproofing and soundproofing materials, to name a few. Localized occurrences can be han dled with a minimum of disturbance to work areas using the established "glove/bag" method. This method in volves isolating small portions of as bestos-laden objects -- sections of piping, valves, fittings, etc. -- with specially designed bags made of polyvi nyl chloride, polyethylene, or similar materials. However, more often the problem is widespread, involving large surfaces such as ceijings, walls, and beams on which asbestos materials have been sprayed or troweled. Asbestos also may be found in materials such as ceiling and floor tiles and wallboard. In gener al, asbestos-containing materials that have been sprayed or troweled are of the greatest concern, especially if the material is friable. Asbestos in this form is most likely to release fibers into the air and create a hazard. Abatement Considerations -- Ideal ly, asbestos abatement is performed when no employees are in the plant. At these times, heating, ventilating, and air conditioning systems, whicn can circulate harmful particles, can be shut down without causing discomfort or interfering with the operation of sensi tive electronic equipment. However, in most industries it is impractical to cease operating for asbestos removal. Instead, good planning must be adopt ed and work areas must be totally isolated. The objective is to assure that as few people as possible are exposed for the shortest possible time to any possible hazards. This goal may be accomplished in various ways. The work can be done when plant staff levels are lowest, for example, on weekends or holidays, or during vacations, although an asbestos removal contractor might charge pre mium rates for these times. Even so, it might be more economical to have a contractor work around-the-clock at favorable times than to have the task completed at the expense of produc tion and employee convenience. When it is not feasible to stop the operation or remove people from the plant, and there is no slack time avail able for asbestos removal, the most practical solution is to isolate the work from the people. Contaminated areas can be sealed off effectively, but spe- Glove/bags allow small portions of asbestos-lad en objects to be isolated and the fibers removed and bandied without any contaminant escaping into the atmosphere. (Courtesy Asbeguard Equipment. Inc., Toronto, Ontario) FILE 7040 FEBRUARY 12, 1987 PLANT ENGINEERING 49 Two workers wearing dual cartridge, high-eSciency, air-purifying res pirators roll up and dis card plastic sheeting -at has covered sun., es during a removal protect One of the most common errors made by workers in donning protective clothing is wearing respi rator headbands over the top of the hoods. They should be worn under the hoods so the contami nated clothing can be dis carded before the respi rators are removed. cial attention must be paid to the duct system, air shafts, ana elevators con nected to the asbestos removal zone. In multifloor structures, it is difficult, but not impossible, to seal all particle es cape routes. All floor penetrations, in cluding those for pipes and electrical conduits, and any hollow outer walls must be considered. Once the need to take action on asbestos abatement has been identi fied, the first step is to select someone to do the job. Many larger plants have inhouse maintenance staffs that, with adequa; '.raining and the right equip ment, ca ; perform the work. Use of an outside contractor also should be con sidered. In either case, the major issue is whether the group can carry out the project efficiently and safely. The experience and capabilities of inplant personnel are known, but an outside firm usually is an unknown quantity. The right questions must be asked to make sure tne firm selected is at a to handle the job. One guideline is contractor certification, but only some states require it. (Fourteen states have active programs, nine additional states are expected to have them within a year.) It more likely will be necessary to probe the track record of the candi date, including checking references. Several other points should be inves tigated. Does the contractor have ade quate safety equipment? Are his em ployees trained to use it? Is he adequately insured? Have any com plaints been filed against him by either customers or government agencies? Has he experienced prematurely ter minated jobs or incurred cost over runs? Surprises can be unpleasant, and it is best to make sure that quality, not potential trouble, is being purchased. Regulations and Exposure Limits -- Both the contractor and plant safety Eersonnel must be aware of multiple azards that may exist during an as bestos cleanup. When a plant keeps operating during abatement work. harmful mists or vapors, or rir.ier. .> nonasbestos particles, may oe zener.r.- ed by normal production processes Such factors will influence the choice of abatement methods, controls, and protective equipment. Conferences should be hela with the contractor and any other personnel involved in the abatement work to discuss the envi ronment and recognize and thwart any hidden hazards in advance. Determining a safe exposure level for airborne asDestos fibers is extreme ly difficult. According to one represen tative of the National Institute for Oc cupational Safety and Health, there is no safe exposure level be cause asbestos is a known carcinogen. Government agencies have struggled with, and for the most part disagreed on. a per missible exposure limit (PEL). Therefore, it is gen erally recommended that those involved :n abate ment work appiy maxi mum protection, using proper personal protec tive equipment, especial ly respirators, ana thor oughly training all workers in proper procedures. Controlling legislation consists of two standards issued by the Occupational Safety and Health Ad ministration, effective July 21, 1986, governing exposures to asbestos, tremolite, antnophyllite, and actinolite. The standards, one for general industry (29 CFR 1910.1001) and one for construc tion (29 CFR 1926.58), reduce the per missible exposure limit for asbestos to 0.2 fiber (longer than 5 jim) per cubic centimeter of air (f/cc) over an 8 hr workday and based on a 40 hr week. This level is the one many abatement contractors already have established for their employee respiratory pro grams. The previous limit, set in 1976, was 2 f/cc with a 15 min exposure level of 10 f/cc. The standards, which have drawn court challenges, set no short-term ex posure limit and prohibit the practice of rotating employees in ana out of asbestos containing areas. They also have set an action level of 0.1 f/cc. At that exposure level, specific programs for monitoring, worker training, and medical surveillance must be initiated. Employees must be equipped with ade quate protective clothing, including coveralls with hoods, gloves, and foot coverings, and be provided with chang ing rooms and showers. They must receive information and training ini tially and be retrained and given a medical examination annually. 50 PLANT ENGINEERING FEBRUARY 12, 1987 FILE 7040 Areas .n which exposure levels might be met or exceeded must be regulated and marked with caution signs. When feasible, negative-pressure enclosures must be established before removal, demolition, or renovation op erations begin. If the exposure level cannot be reduced to or below the limit with engineering and work practice controls, the level must be reduced as much as possible and employees equipped with respiratory protection. The exposure of each employee in a regulated area must be monitored dai ly. except when all employees are equipped with positive pressure, sup plied-air respirators. Monitoring also may be discontinued if reliable measure ments reveal that employee exposure levels are below the action level. The primary source of protection for workers involved in asbestos abate ment activities is respirators. The type of unit selected is based on the air borne concentration of asbestos fibers. For exposures up to 10 times the PEL, negative-pressure, half-mask air-purifying respirators with high-efficiency filters may be used. A nigh-efficiency filter is at least 99.97 percent efficient against monodispersed particles of 0.3 or larger. Full-facepiece air purifying respirators equipped with high-efficiency filters may be used for exposures up to 50 times the PEL because they generally provide a better fit than half-mask units and incorporate eye protection. Negative-pressure respirators must be fit tested on the user initially and checked at least every 6 mo thereafter. A powered air-purifying or constantflow supplied-air respirator is required for exposures between 50 and 100 times the PEL. A powered air-purifying unit is equipped with high-efficiency filters ana a battery-powered air blow er pack worn by the user. For expo sures between 100 and 1000 times the PEL, full-facepiece supplied-air respira tors operatea in the pressure-demand mode are necessary. For exposures to concentrations greater than 1000 times the PEL, or if the concentration is unknown, the user must be protected with a full-facepiece supplied-air respirator operated in the pressure-demand mode and equipped with an auxiliary positive-pressure self-contained breathing apparatus. These combination units consist of a FILE 7040 pressure-demand supplied-air respira tor and a small compressed-air cylin der. If the airflow to the supplied-air hose is reduced or cut off, the user can switch from the supplied-air respirator to the cylinder instantly. Continuous-flow supplied-air respi rators. including hoods, supply a con stant flow of air to the facepiece. Pres sure-demand supplied-air respirators have a mask or belt-mounted regulator that supplies air on demand while maintaining a positive pressure inside the facepiece. Pressure-demand respi rators may be operated from an air cylinder or cascade system or from an air compressor sys tem that provides Grade D air, but not with powered air pumps. Supplied-air respi rators must not De used when the at mosphere is imme diately dangerous to life or health or when the oxygen content of the air is less than 19.5 per cent. A minimum of Grade O air, as de fined in "Commod ity Specification for Air" (Standard G-711966), Compressed Gas Association, must be supplied by a compressor that either does not use internal lubrication or is equipped with suitable filters and temperature and carbon monoxide alarms or by a powered air pump. Workers with facial hair or condi tions that interfere with the seal of a tight-fitting facepiece should use airsupplied hoods. Hoods equipped with a powered air pump or compressed-air system provide respiratory protection and allow communication. The respirable air supplied to all continuous-flow devices (including hoods) and pressure-demand respira tors must be within their approved pressure range and hose-length limita tions and be connected to the air sup ply with an appropriate approved con nection. Under these conditions, the minimum pressure delivers at least 4 cfm of air to the respirator facepiece. The lack of specific information about asbestos abatement makes ad vance planning imperative. Employee understanding is a must to avert any possible hysteria. As long as controver sy about asbestos exists, contractors and employers must be extremely careful to safeguard employee health. A worker protected by e full-facepiece supplied- air respirator removes asbestos-containing ma terial from a ceiling. The respirator is equipped with a bigb-etBcieacy Bi ter that can, should the air supply be interrupt ed, provide a backup sys tem that allows the work er to disconnect from the air line and leave the area safely. For compliimntary copy of this article circle 243 on poet card FEBRUARY 12, 1987 PLANT ENGINEERING 51 Quite a mess of oil. isn't it? Discouraging, isn't it? we also have Pig Pans tor drips. Now you've got to stop Now for the good news. And Haz Mat Pigs for acids, whatever you're doing and You can stop using clay. And caustics and other hazardous start cleaning up the whole start feeding your messes to materials. All of which do the mess. our pigs. same incredible job. the same But wait. Before you start Actually, what you do is incredible way. pouring clay all over the wrap a PIG around the We know our pigs are the place7 let us explain why you machine making the mess. Or best way to clean up all your shouldn't. And don;t need to. around a spill. And that pig messes. Clay doesn't really absorb will suck up to a half gallon of much of anything. oil in just minutes. But vj ou don't. That's why you need so Why, that's faster than any That's much of it. And why oil slips human could drink it. right past it. And why it's . And, unlike clay which has Pigs literally suck up oiL why we're backing such a pain to clean up messes to be trucked to a landfill, when our pies with it. our pig has picked up the whole Clay also happens to be a mess, you just pick up the particularly nasty pig and throw it in substance around an incinerator.* anrything except Just like that. caits. IIdt'ss haard and gritty. So it can go right Clay leaks. But wait, there's more. through your machine's Besides pigs for oil seals and couplings, creating more leaks, drips and spills and the need for more clay. * Pig must oc disposed or n lompuance with :ocii suit uv: federal resuuoons P!C is i retwered trademark or New Pig Corporation Patent Pending strenuous action to eliminate possible asbestos sources. In these cases, it is important to communicate with the people involved and tell them what is happening and what is going to happen during the cleanup effort. Calling in a communications expert is often advisable." Before any asbestos abatement work is done, the plant should conduct a complete survey. According to an as bestos abatement contractor, Dwight Hopkins of Cross Construction Co., Jacksonville. FL, plant workers often tear into asbestos-laden areas and cre ate contamination before they realize they should have evaluated the entire project in advance. One company, he notes, started to clean up an old boiler and realized too late that the duct work was also a source of contamination. More communication on the subject is needed. Unfortunately, not a great deal of information exists about the asbestos problem in industrial plants, or on abatement and control methods. Use of the material in industry was similar to that in other facilities. It was applied as insulation on hot or cold water pipes, ducts, boilers, and tanks. It can be found almost anywhere: in kilns in a glass plant, between the corrugated siding and the outer covering on an old building, in gaskets, and in fireproofing and soundproofing materials, to name a few. Localized occurrences can be han dled with a minimum of disturbance to work areas using the established "glove/bag" method. This method in volves isolating small portions of as bestos-laden objects -- sections of piping, valves, fittings, etc. -- with specially designed bags made of polyvi nyl chloride, polyethylene, or similar materials. However, more often the problem is widespread, involving large surfaces such as ceilings, walls, and beams on which asbestos materials have been sprayed or troweled. Asbestos also may be found in materials such as ceiling and floor tiles and wallboard. In gener al, asbestos-containing materials that have been sprayed or troweled are of the greatest concern, especially if the material is friable. Asbestos in this form is most likely to release fibers into the air and create a hazard. Abatement Considerations -- Ideal ly, asbestos abatement is performed when no employees are in the plant. At these times, heating, ventilating, and air conditioning systems, which can circulate harmful particles, can be shut down without causing discomfort or interfering with the operation of sensi tive electronic equipment. However, in most industries it is impractical to FILE 7040 cease operating for asbestos removal. Instead, good planning must be adopt ed and work areas must be totally isolated. The objective is to assure that as few people as possible are exposed for the shortest possible time to any possible hazards. This goal may be accomplished in various ways. The work can be done when plant staff levels are lowest, for example, on weekends or holidays, or during vacations, although an asbestos removal contractor might charge pre mium rates for these times. Even so. it might be more economical to have a contractor work around-the-clock at favorable times than to have the task completed at the expense of produc tion and employee convenience. When it is not feasible to stop the operation or remove people from the plant, and there is no slack time avail able for asbestos removal, the most practical solution is to isolate the work from the people. Contaminated areas can be sealed off effectively, but spe- Glove/bags allow small portions of asbestos-lad en objects to be isolated and the libers removed and handled without any contaminant escaping into the atmosphere. (Courtesy Asbeguard Equipment, Inc., Toronto, Ontario) FEBRUARY 12, 1987 PLANT ENGINEERING 49 Two workers wearing dual cartridge. high-efBciency, air-purifying res pirators roll up and dis card plastic sheeting that has covered surfaces during a removal project. cial attention must be paid to the duct system, air shafts, and elevators con nected to the asbestos removal zone. In multifloor structures, it is difficult, but not impossible, to seal all particle es cape routes. All floor penetrations, in cluding those for pipes and electrical conduits, and any hollow outer walls must be considered. Once the need to take action on asbestos abatement has been identi fied, the first step is to select someone to do the job. Many larger plants have inhouse maintenance staffs that, with adequate training and the right equip ment, can perform the work. Use of an outside contractor also should be con sidered. In either case, the major issue is whether the group can carry out the project efficiently and safely. The experience and capabilities of inplant personnel are known, but an outside firm usually is an unknown quantity. The right questions must be asked to make sure the firm selected is able to handle the job. One guideline is contractor certification, but only some states require it. (Fourteen states have active programs, nine additional states are expected to have them within a year.) It more likely will be necessary to probe the track record of the candi date, including checking references. Several other points should be inves tigated. Does the contractor have ade quate safety equipment? Are his em ployees trained to use it? Is he adequately insured? Have any com plaints been filed against him by either customers or government agencies? Has he experienced prematurely ter minated jobs or incurred cost over runs? Surprises can be unpleasant, and it is best to make sure that quality, not potential trouble, is being purchased. Regulations and Exposure Limits -- Both the contractor and plant safety personnel must be aware of multiple hazards that may exist during an as bestos cleanup. When a plant keeps operating during abatement work. harmful mists or vapors, or dangerous nonasbestos particles, may be generat ed by normal production processes. Such factors will influence the choice of abatement methods, controls, and protective equipment. Conferences should be hela with the contractor and any other personnel involved in the abatement work to discuss the envi ronment and recognize and thwart any hidden hazards in advance. Determining a safe exposure level for airborne asbestos fibers is extreme ly difficult. According to one represen tative of the National Institute for Oc cupational Safety and Health, there is no safe exposure level be cause asbestos is a known carcinogen. Government agencies have struggled with, and for the most part disagreed on. a per missible exposure limit (PKL). Therefore, it is gen erally recommended that those involved in abate ment work apply maxi mum protection, using proper personal protec tive equipment, especial ly respirators, ana thor oughly training all workers in proper procedures. Controlling legislation consists of two standards issued by the Occupational Safety and Health Ad ministration, effective July 21, 1986, governing exposures to asbestos, trem- olite, anthophyilite, and actinolite. The standards, one for general industry (29 CFR 1910.1001) and one for construc tion (29 CFR 1926.58), reduce the per missible exposure limit for asbestos to 0.2 fiber (longer than 5 Mm) per cubic centimeter of air (f/cc) over an 8 hr workday and based on a 40 hr week. This level is the one many abatement contractors already have established for their employee respiratory pro grams. The previous limit, set in 1976, was 2 f/cc with a 15 min exposure level of 10 f/cc. The standards, which have drawn court challenges, set no short-term ex posure limit and prohibit the practice of rotating employees in ana out of asbestos containing areas. They also have set an action level of 0.1 f/cc. At that exposure level, specific programs for monitoring, worker training, and medical surveillance must be initiated. Employees must be equipped with ade quate protective clothing, including coveralls with hoods, gloves, and foot coverings, and be provided with chang ing rooms and snowers. They must receive information and training ini tially and be retrained and given a medical examination annually. Areas in which exposure levels might be met or exceeded must be regulated and marked with caution signs. When feasible, negative-pressure enclosures must be established before removal, demolition, or renovation op erations begin. If the exposure level cannot be reduced to or below the limit with engineering and work practice controls, the level must be reduced as much as possible and employees equipped with respiratory protection. The exposure of each employee in a regulated area must be monitored dai ly, except when all employees are equipped with positive pressure, supplied-air respirators. Monitoring also may be discontinued if reliable measure ments reveal that employee exposure levels are below the action level. The primary source of protection for workers involved in asbestos abate ment activities is respirators. The type of unit selected is based on the air borne concentration of asbestos fibers. For exposures up to 10 times the PEL, negative-pressure, half-mask air-purifying respirators with high-efficiency filters may be used. A high-efficiency filter is at least 99.97 percent efficient against monodispersed particles of 0.3 pm or larger. Full-facepiece air purifying respirators equipped with high-efficiency filters may be used for exposures up to 50 times the PEL because they generally provide a better fit than half-mask units and incorporate eye protection. Negative-pressure respirators must be fit tested on the user initially and checked at least every 6 mo thereafter. A powered air-purifying or constantflow supplied-air respirator is required for exposures between 50 ana 100 times tne PEL. A powered air-purifying unit is equipped with high-efficiency filters ana a battery-powered air blow er pack worn by the user. For expo sures between 100 and 1000 times the PEL, full-facepiece supplied-air respira tors operated in the pressure-demand mode are necessary. For exposures to concentrations greater than 1000 times the PEL, or if the concentration is unknown, the user must be protected with a full-facepiece supplied-air respirator operated in the pressure-demand mode and equipped with an auxiliary positive-pressure self-contained breathing apparatus. These combination units consist of a FILE 7040 pressure-demand =uppi:ed-a:r respira tor and a small compressed-air cylin der. If the airflow to the supplied-air hose is reduced or cut off. the user can switch from the supplied-air respirator to the cylinder instantly. Continuous-flow supplied-air respi rators, including hoods, supply a con stant flow of air to the facepiece. Pres sure-demand supplied-air respirators have a mask or belt-mounted regulator that supplies air on demand while maintaining a positive pressure inside the facepiece. Pressure-demand respi rators may be operated from an air cylinder or cascade system or from an air compressor sys tem that provides Grade D air, but not with powered air pumps. Supplied-air respi rators must not oe used when the at mosphere is imme diately dangerous to life or health or when the oxygen content of the air is less than 19.5 per cent. A minimum of Grade D air, as de fined in "Commod ity Specification for Air" (Standard G-711966), Compressed Gas Association, must be supplied by a compressor that either does not use internal lubrication or is equipped with suitable filters and temperature and carbon monoxide alarms or by a powered air pump. Workers with facial hair or condi tions that interfere with the seal of a tight-fitting facepiece should use air- supplied hoods. Hoods equipped with a powered air pump or compressed-air system provide respiratory protection and allow communication. The respirable air supplied to all continuous-flow devices (including hoods) and pressure-demand respira tors must be within their approved pressure range and hose-length limita tions and be connected to the air sup ply with an appropriate approved con nection. Under these conditions, the minimum pressure delivers at least 4 cfm of air to the respirator facepiece. The lack of specific information about asbestos abatement makes ad vance planning imperative. Employee understanding is a must to avert any possible hysteria. As long as controver sy about asbestos exists, contractors and employers must be extremely careful to safeguard employee health. A worker protected by e full-facepiece suppliedair respirator removes asbestos-containing ma terial from a ceiling. The respirator is equipped with a high-efficiency fil ter that can. should the air supply be interrupt ed, provide a backup sys tem that allows the work er to disconnect from the air line and leave the area safely. For complinwritary copy of this artlcla circia 243 on poat card FEBRUARY 12, 1987 PLANT ENGINEERING 51 \sbestos: menace in he boiler room ? avoid the tragedies from asbestos related .seases, HVAC workers should have a full nderstanding of asbestos and how to deal with it /ir'J 7 c-,; >*. /lre&To> 's**?-- alalcg 4 i *> DANIEL CULBEKG, resident, rand Asbestos C- nrol Co.. ark Ridge, 111. Since the mid 1970s. concern for sbeo.os related health problems ras focused on those who worked t.rectlv with asbestos. More re cently, however, the focus has shifted to people who work in any environment where asbestos may be present. HVAC workers fail into both categories. The Environmental Protection Agency has reported that while can cer risk from asbestos for people in an urban environment is one in 10,000, the risk for highly exposed construction workers is one in 10. The accuracy of such risk projec tions and what constitutes "high ex posure" can of course be questioned, particularly since experts are far from agreement on what consti tutes a dangerous level of exposure. There are documented cases of death resulting from only inci dental exposure to asbestos. At the other end of the spectrum, research in an asbestos mining town where the air is laden with asbestos part icles showed that this posed no sig nificant health problem. However, what is indisputable is the fact that workers continue to die from asbestos related diseases. Cur rently, more than 8000 die each year, and by the year 2000, sci entists believe that figure will reach 10,0u0ayear. Unfortunately, HVAC workers find themselves full-square in the middle of this controversy. It has been over a decade since workers installed asbestos insulation on and around HVAC systems. But most of what they did install remains in place, endangering the health of those who now must repair and maintain those systems. To avoid a repeat of the tragedy that befell those who installed as bestos containing materials, today's HVAC worker should have a full un derstanding of the issues sur rounding asbestos, what it is, where it's found, when it is dangerous, and how it should be dealt with. What is asbestos? Asbestos is a generic term for a group of naturally occurring fibrous minerals. Asbestos is virtually inde structible. When separated or bro ken down, even to its molecular level, asbestos remains an extremely tough fiber. This characteristic is asbestos' greatest attribute--and its tragic flaw. Asbestos is mined all over the world and is found primarily in Canada, the Soviet Union, Austra lia, and South Africa. There are five major types of asbestos: Chrysotile (white asbestos). Crocidolite (blue asbestos). Amosite (brown asbestos). Anthrophyllite. lYemolite. Historians trace the first use of asbestos back to the 5th century BC when it was used as lamp wick. Tou ted as the miracle fiber of the 20th century, its mechanical strength, fire resistance, flexibility, and good wear characteristics made asbestos the mineral of choice in a wide vari ety of products from construction materials to clothing. Asbestos was used commercially as fireproofing as early as the 1890s. The use of asbestos in insulation materials began in England early in the 1900s and continued through the mid 1970s in the United States. At the height of its popularity, more than 3000 commercial appli cations of asbestos were in use. Its low cost and the ease with which it can be mixed with binders and spray applied created applications for millions and millions of tons of the mineral Asbestos' ability to be woven into thread or cloth made asbestos pop ular in fire resistant clothing, cur tains, and draperies. Its fire and heat resistant properties provided innumerable uses for asbestos as an extremely versatile building mate- l1 ,, Conditioning February 1987 33 Asbestos menace rial. It is believed that at least one asbestos containing product can be found in virtually every building constructed from 1900 to the mid 1970s. Promise turns to disaster The promise of this "miracle fi ber" turned to disaster after nearly 100 years of modern use when in the between asbestos and disease was also established by medical re searchers in the United States. But again, the problem was considered an occupational hazard that could be controlled by controlling the lev els of dust in the manufacturing en vironment. This assessment of the problem was supported in a 1945 study of Table ^ --Types cf asbestos most commonly used. QeysoBe Amosite______________ Whitt asbestos 90% of usage fkgh tensile strength Good overai workabdity Used in fireproofing w ' and insulating materials Brown asbestos Coarse, good Good acid resistance Less flexible and workable than chrysolite Used principally in high temperature products Croddoite Blue asbestos High tensile strength Acid resistant Low resistance to heat Good flexibility and (air workability______ mid 1970s asbestos was proved to be a cancer causing agent. While the useful properties of as bestos were known for centuries, it was not until the early 1900s that asbestos became suspect as a poten tial health hazard. Early warnings ofasbestos related health hazards in the workplace focused on the Brit ish textile industry where heavy concentrations of asbestos-laden a. - jome dust were common. The first connection between as bestos dust and disease was publis "ad in a British medicaljournal in 19'S, and in 1924 the first known caje of asbestosis (a lung disease) was documented. In 1930, Dr. E. R. A. Merewether, a British govern ment factory inspector, published a study that solidified the re lationship between disease and heavy concentrations of asbestos dust in textile plants. Heavy concentrations of dust, as opposed to asbestos itself, seemed to be the culprit. As a result, in 1931 regulations were put in place to in crease ventilation and thereby de crease visually obvious dust in the environment. As yet, no direct con nection between asbestos and can cer was made. By the late 1930s, a correlation pipe insulation/covering operations that concluded that this operation was relatively safe. However, sub jects of the study had been at their jobs less than 10 years whereas as bestosis symptoms take 10 to 20 years to become apparent. It was not until 1965 that a true link between asbestos and cancer was established. In that year. Dr. Irving Selikoff studied over 1500 in sulation workers who had been at the trade for a significant length of time. Selikoff found that of workers with more than 40 years in the in dustry, more than 90 percent had asbestosis related medical prob lems. The real scope and magnitude of the problem were beginning to be recognized. Since that time, asbestos has Table 2--Categories of asbestos containing materials. Friable materials are those that can be crumbled, pulverized, or reduced to powder in the hand, readily releasing fibers with minimal mechanical disturbance. Friable Nonfriabie Sprayed-on fireproofing Thermal insulation . Textiles Cementitious products Paper products Roofing felts been identified as one of only eight known naturally occurring cancer causing agents. All five types of as bestos can cause cancer. There is no "safe" type of asbestos. The regulatory environment By 1973, the government moved to ban asbestos containing materi als from new construction. In that year, the EPA Clean Air Act pro hibited spraying of asbestos con taining materials. In 1975, all asbes tos was banned from use in pipe, boiler, and other types of thermal insulation. In 1976, Occupational Safety and Health Administration (OSHA) standards mandated removal for applications where asbestos fibers 5m or longer were present in the at mosphere with a density of two fih :.*s per cu cm or greater. Recently, allowable limits were reduced to 0.2 fibers per cu cm. These two agencies, OSHA and the EPA, are in the forefront of reg ulation regarding asbestos control. OSHA regulates exposure to asbes tos in the workplace, and the EPA regulates the use, removal, and dis posal of materials containing asbes tos under authority of the Clean Air Act and Toxic Substances Control Act. EPA regulations focus primarily on applying and removing asbestoscontaining materials in new or re modeled buildings and on identi fying friable asbestos in schools. There are no federal require ments mandating tests to deter mine asbestos levels in commercial buildings unless building reno vation or asbestos removal is planned. When renovation or removal is planned, EPA regulations call for filing notice with the agency's re gional office and sometimes the state if more than 260 ft of asbestos pipe insulation or 160 sq ft of asbes tos surfacing material will be re moved. The notice must name the building's owners, location, and de scription; how the removal will be done; and where the asbestos will be disposed. 34 Heating/Piping/Air Conditioning February 1987 When problematic asbestos is identified in a building or reno vation is planned, the federal stan dards governing asbestos control are lengthy, detailed, and quite spe cific. Also, many states are estab lishing or strengthening existing training and enforcement programs for asbestos removal. Fourteen states have certification programs, and 15 others have bills pending in their legislatures. A dozen states al ready have licensing and training requirements for asbestos removal contractors, although only four of these have been in force for over a year. When it is dangerous Asbestos is virtually everywhere: in auto brake linings, in electric hair dryers, and in nearly every building constructed from 1900 to the mid 1970s. Asbestos-containing materials are found on ceilings, walls, and structural beams where they were sprayed or trowled on. Asbestos is also common as insulation around hot or cold pipes, ducts, boilers, and tanks. It is also found in many building materials such as tile and wailboard. Sprayed-on asbestos and asbes tos in pipe insulation are of greatest concern to the owners of commer cial/industrial buildings and the people who service their HVAC sys tems. It is in these applications that asbestos is most often in a danger ous state. Asbestos is dangerous only when it is "friable," that is, old and crum bling. In its friable state, asbestos can be crumbled, pulverized, and reduced to powder in the hand. Fri able asbestos does not have to be visible as airborne dust to be dan gerous. Minimal disturbance re leases microscopic asbestos part icles into the air that are so light they may take days to settle. Asbestos-containing materials that are usually considered nonfriable include cementitious prod ucts, paper products, and roofing felts. Categories of materials that are likely to become friable with Asbestos insulation on piping and ductwork is hazardous in a friable condition when it can be crumbled or reduced to powder by hand pressure alone. time include sprayed-on fire proofing, textiles, and all types of asbestos-containing insulation. Experts agree conservatively that 1 million tons of friable asbestos materials are in schools, shops, Of fices, and industrial buildings as thermal and acoustic insulation. It has been estimated that 21 million living Americans have been exposed to asbestos in the workplace. Routine activity, including the installation of phone lines, HVAC system work, and general mainte nance, can free asbestos into the air, endangering workers and building occupants. Dangerous amounts of asbestos can also be freed into the atmosphere in and around a build ing during renovation and related construction. Asbestos fibers have the tensile strength of steel and are sharper than fine needles. Asbestos part icles are microscopic in size; it would take as many as 1 million fibers laid side-by-side to measure just 1 in. When these fibrils escape into the air, they are easily inhaled or swal lowed. Asbestos fibers that are in haled and enter the lungs stay there for life. They may also enter the blood stream or the lymphatic sys tem where they are transported throughout the body. Asbestos has been linked to asbestosis; cancers of the lung, es ophagus, stomach, colon, and other organs; and mesothelioma, a cancer of the chest and abdominal lining that is extremely rare except when asbestos is involved. Asbestos ranks second as the leading cause of cancer. Only ci garettes rank higher. Asbestos re Respiratory protection is standard equip ment tor workers to prevent the inhalation or ingestion of hazardous asbestos fibers. lated cancer is usually inoperable as cancer cells cluster around micro scopic asbestos fibers that lodge throughout the system. As a result, it is almost always incurable. More than 100,000 workers have died as a result of installing asbestos years ago. Leading experts on the subject project at least an additional 300,000 deaths from asbestos re lated cancer in the next 25 years. The dilemma The asbestos abatement industry is headed for increasing attention because of strict state and federal legislation on the books and in the wings. In addition, record court awarded settlements of asbestos re- Heating/Piping/Air Conditioning February 1987 3S Asbestos menace lated lawsuits and the documented health hazards of asbestos are cre ating greater public awareness of the problem. Commercial buildings built be fore 1973 suffer an added penalty. Mortgage lenders, investors, insur ers, and potential tenants are grow ing hesitant to become involved in buildings that contain asbestos. The result is potential economic lia bilities for owners and managers of these buildings. For commercial building owners and managers, the asbestos di lemma assumes two dimensions, safety and economics, both com pounded by the lack of qualified people who can help. Up to 75 per cent of all asbestos related projects are done improperly, according to estimates of industry experts and federal agencies. Federal and state agencies cited more than 1300 vio lations last year. Most industry observers agree that the high incidence of poor workmanship in asbestos abate ment stems from several factors. Among them are the lack of train ing, the "quick buck" artists who entered the business, and the ten dency of building owners to accept the lowest bid for removal. This ob viously has serious implications for the health and safety of the work crews but also for those surrounding the work area. With large asbestos control con tracts at stake for renovation of commercial and industrial build ings, many contracting firms are vying for success in asbestos abate ment. While there are many reputa ble, experienced, and qualified firms in the business, the concern over asbestos related issues has spa wned numerous "opportunistic" newcomers. Many of these firms are under capitalized, staffed with untrained people, uninsured or underinsured, and generally ill-equipped to do a safe, competent job of asbestos con trol or abatement. For some of them, the path to contracts is the low bid. But for their clients, that path could lead to health dangers, lawsuits, and eco nomic disaster. It's easy to take shortcuts on an asbestos removal project. Since health effects of shoddy practices may not show up for decades, it is sometimes difficult to know exactly when or how the poor work was done when it is less than obvious. The work of unqualified con tractors has given rise to many hor ror stories about inept and danger ous practices. For example, workers have been seen gathering up asbes tos debris with brooms "the way you clean up your garage," an EPA offi cial told the Wall Street Journal. In another example, asbestoscoated workers tramped into a building cafeteria for lunch, ex posing the diners, cafeteria person nel, and the food to significant haz ard, not to mention the danger the asbestos workers themselves were courting. The insurance environment The hesitancy shown by many owners of older buildings to reno vate, by lending institutions to fi nance, and by insurers to cover the work is due in no small part to the ever present possibility that some How to identify asbestos All sprayed-on fireproofing and insulation materials used prior to the early 1970s have a good chance of containing some type of asbestos. Sprayed-on-- fireproofing is usually foundon ceilings and/or above suspended ceilings in all types of buildings. Thermal insulation products such as steam and cold water piping and boiler insulation are ; found in many commercial and *ij\ industrial buildings. day liability claims for asbestos re lated illnesses may be filed. Adding to that concern is the way all insurers are now writing liability policies. Major changes in the in dustry in recent years have been triggered by the hundreds of mil lions of dollars paid to settle asbes tos related claims on policies 30 or 40 years old. By one estimate, asbes tos related settlements could cost insurance companies up to $87 bil lion in payouts over the next several decades. This has led to a big difference in the types of policies insurers are now writing. The insurance indus try is shifting from the long-term liability coverages of "occurrence" type policies to short-term "claims Well protected, well trained technician ap plying wetting agent to asbestos pnor to removal. 36 Heating/Piping/Air Conditioning February 1987 r de" type policies. The claims made policy has be- c ne the policy of choice for insur :e companies because the insur are responsible only for defense a i payment of claims Sled during t short-term period while the poli is in force. A claims made policy v 11 not cover claims for injuries or i mages filed after the policy has e pired--even if the injury or dama e took place during the policy per. xi. Under the terms of an occurrence p )licy, the insurer pays claims for ail injuries and property damage oc curring during the policy period. The big advantage to policy holders is that once the policy is written, claims can be made at any time af terward. These policies cover acts, errors, and omissions that occur during the policy period. The in surer is responsible for paying claims at any time in the future fol lowing an "occurrence"--even after the policy is no longer in force. The difference between the two types of insurance coverage is of par ticular significance considering that asbestos related illnesses typically take up to 40 years or more to man ifest themselves. Simply put, insurance experts agree that occurrence type insur ance affords adequate protection while claims made insurance does not. As this whole issue becomes more volatile, additional changes will oc cur in the types and amounts of in surance available. The insurance in dustry will continue to minimize its long-term liability by decreasing coverages in policies. This will in crease the asbestos removal con tractors' (and their customers') fu ture business related risks. It is, therefore, of paramount im portance for the customer to deal with large, well managed, finan cially stable asbestos abatement contractors. When there are only a few companies left who can obtain occurrence type insurance coverage, it will be this kind of firm that will have it. Abatement, the first step The first step in an asbestos abatement program is risk analysis. Whether the asbestos in a given building is contaminating the envi ronment and posing a real danger can be determined only by an on site audit. While most HVAC workers can probably recognize and identify as bestos, this work is best performed by an experienced and qualified registered industrial hygienist or abatement professional. These peo ple will collect samples of suspected asbestos in a manner that will not disturb surrounding materials and send them to an independent labo ratory for analysis. While any HVAC worker can col lect samples, the danger of the worker being exposed or unneces sarily releasing asbestos fibers into the air while collecting samples is great. Also, a hygienist or other competent professional will know of the best independent laboratories for testing. Once it has been determined that asbestos is present, four factors should be considered prior to decid ing what, if anything, should be done about it. These four factors are damage, friability, location, and air movement. Asbestos causes little concern if it is in perfect condition. If asbestos is found in good condition, leave it alone! However, if the asbestos has been frayed or damaged, it should be either removed or contained. Asbestos also poses a problem when it is located where it may be disturbed by building occupants, maintenance personnel, or the vi bration of machinery or building ac tivity. Air movement around friable asbestos is extremely problematic. Microscopic particles of asbestos are easily transported by the slight est draft or air movement. Considering that significant amounts of asbestos were originally installed as insulation for HVAC components, the danger of friable asbestos entering the HVAC system and circulating throughout an en tire building is great. When asbestos is determined to be problematic by virtue of damage, friability, location, or air movement, an abatement program is in order. Asbestos abatement can constitute one or more of three basic abatement methods: removal, en closure, or encapsulation. The choice among all three tech niques depends on the condition of the asbestos-containing^ material; i.e., whether is is rated as good, showing minor damage, or poor. Re moval is generally perceived to be the most desirable choice since the other alternatives are considered temporary. Removal can cost anywhere from $10 to $25 per sq ft, a high price in a multi-million sq ft building. Two somewhat lower priced alternatives for asbestos abatement are en- 987 Heating/Piping/Air Conditioning February 1987 37 Asbestos menace closure and encapsulation. Enclosure involves construction of airtight drywalls around the ma terial. Encapsulation is achieved by spraying the material with a seal ant. Neither is recommended when dealing with highly friable asbestos. In this case, proper and safe re moval is the preferred method for eliminating this imminent health hazard. Selecting an abatement firm Once a decision is reached that asbestos abatement--removal, en closure, or encapsulation --is needed, the next step is to select a qualified firm to do the work. That is not as simple as it may seem. It's not just a matter of looking in the Yellow Pages, asking a few firms for bids, and then choosing the low est. In fact, that may be the worst way. There are, unfortunately, some firms that will low ball a job, bidding their work at break even or below, merely to gain experience and to train people. Too often, however, they find the project quickly be comes unprofitable. So they seek additional contracts, again low ball ing their bids. Then, to make up for unsatisfactory profit margins, the shortcuts and slipshod and unsafe work begin. To avoid this scenario, an ap proach in pricing asbestos abate ment projects that is growing in popularity is price negotiation as opposed to contract bidding. Larger, more reputable firms are willing to work at a negotiated price. The privacy of negotiations also preserves the confidentiality of a project if necessary. Letting out bids, on the other hand, is a good way to tell the world that a building may have an asbestos related prob lem. The key is to identify a competent organization with a successful track record in asbestos abatement--one that has mastered practices ap proved by regulatory agencies to en sure the safety of tenants, the workers on the job site, and the surrounding environment. Cleanup of asbestos debris. All work is carried out within containment to prevent the release of asbestos fibers to the surrounding environment Preliminary packaging of asbestos debris prior .3 final packaging and shipment to EPA approved waste sites. The movement toward in creasingly sophisticated and ex pensive asbestos abatement equip ment is expected to knock smaller, less reputable firms out of the busi ness. OSHA and industry leaders, for example, are backing more rou tine use of Type C equipment, which through a remote air system con tinually creates a negative air pres sure in the containment area, thereby preventing breaches and providing maximum protection to workers inside. Compared to half-masks and per sonal battery powered air packs, this type of equipment is the cream of the crop and an expensive in vestment. Asbestos control firms must be well capitalized and intend to stay in the business to purchase this equipment. And operators must be extremely well trained to use it. Weeding out the less than com petent contractors can still be tricky business. There are several screening criteria that can be ap plied to find the good ones. Insurance--With the changes taking place in the insur ance industry concerning liability 38 Heating/Piping/Air Conditioning February 1987 coverage (i.e., the trend toward writing short-term claims made vs. long-term occurrence policies), a copy of the contractor's certificate of insurance should be part of the bid package. Sharp building owners and managers have also begun ask ing for a notarized letter from the contractor's insurance broker stat ing that the contents of the insur ance certificate are in fact authentic and current. The client should ask how much and what kind af insurance the con tractor carries. Since occurrence type policies offer the best protec tion and since they are hard to get, ^nly the large, well managed, and financially stable companies can qualify. Performance bonding--Be cause of the enormous risk that as bestos lawsuits pose, asbestos abatement firms should be bondable for large projects, and the bond should be backed by the U.S. Trea sury. Large, well capitalized, stable firms with a minimum net worth of at least $5 million are the safest partners when undertaking an as bestos abatement program. These are the companies that will remain solvent and continue in business should liabilities arise. e Training--The contractor's asbestos removal personnel must be thoroughly trainwi, with dangers dearly outlined to them, protective and safety measures presented and explained, and workers tested as to how well they learned. Moreover, on-the-job training and retraining should take place as well as class room instruction. Safety of contractor employ ees--In addition, the responsible firm does not employ smokers or permit bearded workers on asbestos jobs. Studies have proved that a smoker's chances ofdeveloping lung cancer are many times greater than a nonsmoker's. Beards prevent proper respirator fit. Respirators should be approved by the National Institute of Occupational Safety and Health, and Kill body protec tive clothing, eye protection, head gear, and footwear should also be used. e Referrals--References should be checked for all prospective con tractors. Some things to ask: How big a job was it? Was it done profes sionally, on time, and within bud get? What kind of air and bulk sam pling were done? Were proper authorities involved as required? Were project management and worker safety and training satis factory? Other criteria include the use of insured waste haulers and EPA ap proved dump sites, the ability to render 24 hr emergency services, third party verification of compli ance with federal and other guide lines, and the contractor's ability to perform confidentially. The hitch Where problematic asbestos is identified, it must be dealt with; that's the law. However, there is as yet no federal directive requiring as bestos audits, monitoring, or test ing in commercial or industrial buildings unless renovation is planned. For that matter, it is not even required that owners deter mine whether a building has asbes tos-containing materials. How then can HVAC workers, or any employee, protect themselves from this menace? The answer is found in OSHA's Occupational Safety and Health Act. OSHA's Occupational Safety and Health Act includes a general clause that mandates that employ ers must provide a safe workplace for all employees. In addition to this general clause, OSHA has a number of specific standards for particular toxic substances, including asbes tos. An employee may not be exposed to over 0.2 fibers of asbestos per cu cm of air averaged over an 8 hr day. In addition, OSHA has specified an "action level' of 0.1 fibers per cu cm of air averaged over 8 hr. If this level is exceeded, employers must begin air monitoring, employee training, and medical surveillance. Wetdown procedures and ven tilation methods can be attempted to comply with the limit. If these fail to reduce the exposure level to within the standard, respirators must be worn. Employees must _.so be provided with protective cloth ing and a changing room. OSHA also stipulates that warn ing signs and labels must be used in asbestos work areas and on waste disposal containers. In addition, employers must monitor the expo sure level and maintain records. Protecting yourself Asbestos abatement is serious and dangerous work--too serious and too dangerous to ever be consid ered as part of HVAC work. Once asbestos enters the lungs, it stays there forever. While no minimum dangerous exposure to asbestos has been established, once may be enough. HVAC workers who smoke should never work around asbestos. Smok ing and asbestos have a synergistic effect on increasing the risk of can cer. Experienced asbestos abate ment contractors have a policy of not hiring smokers because it has been shown that smokers are 50 to 90 times more susceptible to asbes tos related lung cancer than nonsmokers. The message to others who work in areas where asbestos may be present is clear. In addition, HVAC workers with beards should not attempt to work near asbestos even while wearing respirators. Beards prevent proper fitting of respirators. As a final caution, it is an unfortu nate fact that many years ago HVAC workers installed asbestos, worked near the installation of as bestos, or handled asbestos in the course of routine work and thus were exposed to its dangerous ef fects. Do not repeat this exposure by working on or around asbestos removal. First line of defense The first line of defense in pre venting asbestos related health Heating/Ptping/Ajr Conditioning February 1987 39 I ! 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