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National Bureau of Standards Special Publication 506. Proceedings of the Workshop on Asbestos: Definitions and Measurement Methods held at NBS, Gaithersburg, MD, July 18-20, 1977. (Issued November 1978) CPSC REGULATION OF NON-OCCUPATIONAL EXPOSURE TO ASBESTOS IN CONSUMER PRODUCTS Robert M. Hehir, Steven P. Bayard, and June Thompson Consumer Product Safety Commission 5401 Westbard Avenue Bethesda, Maryland 20207 Abstract The Consumer Product Safety Commission (CPSC) has found that exposure to respirable free-form asbestos in two consumer products poses an unreasonable health risk. The Commission has recently voted to propose bans on the use of free-form asbestos in consumer patching compounds and in artificial fireplace ash or emberizing materials under Section 8 of the Consumer Product Safety Act. The broad regulatory provisions under CPSA, as well as those under the Federal Hazardous Substances Act (FHSA) are discussed. Data on consumer exposure to asbestos are very limited. One study of airborne asbestos resulting from use of consumer spackling/patching compounds has reported levels of airborne asbestos fibers exceeding the occupational exposure levels. Direct evidence exists of asbestos inhalation in non-occupationally exposed individuals from autopsy findings of asbestos fibers in lung tissue and indirect evidence of asbestos-related cancers in non- occupationally exposed individuals from epidemiological studies. A risk assessment has been made of the potential increase of lung cancer deaths resulting from consumer exposure to asbestos containing patching compounds. Key Words: Artificial fireplace ash; consumer exposure; Consumer Product Safety Act (CPSA); Consumer Product Safety Commission (CPSC); emberizing material; free-form asbestos; patching compounds; risk assessment. Introduction The Consumer Product Safety Commission (CPSC) has broad regulatory authorities under several Acts to help it marshal its resources to reduce unreasonable risk of injury associated with consumer products. When risks of injury resulting from reasonable or reasonably foreseeable use of consumer products are brought to the Commission's attention, either through petitions or through findings from in-house or externally-sponsored studies, the regulatory mechanism which can most appropriately remedy or prevent an identified hazard is utilized. Thus, in a recent decision, the CPSC Commissioners voted to regulate respirable, free-form asbestos in two consumer products (consumer patching compounds and artificial fireplace ashes) under Section 8 of the Consumer Product Safety Act (CPSA) [16]1. It is the sequence of this regulatory process which I will discuss today. 'Figures in brackets indicate the literature references at the end of this paper. r ~ Preceding page blank 451 ~-

Prior to promulgating a safety rule under the CPSA, the Commission must first propose a rule for public comment. In issuing a final rule, it must make special findings under sec. (9) subsection (c) of the CPSA. Such findings include: (a) the degree and nature of the risk of injury the rule is designed to eliminate or reduce; (b) the approximate number of consumer products, types or classes that will be subject to the rule; (c) the need of the public for the product and probable effect of such rule upon the utility, cost, or availability of such products to meet such needs; and (d) any means of achieving the objective of the order while minimizing adverse effects on competition or disruption or dislocation of manufacturing... etc., consistent with the public health and safety. In addition, the Commission must consider other things as well: (a) Which Act will be used in promulgating the rule. (Sec. 30 CPSA). (b) Jurisdiction under Section 3(a) and Section 31 CPSA. (c) Under CPSA, if the Commission preliminarily determines that a product presents an unreasonable risk of injury, it could commence proceedings to develop a mandatory safety standard addressed to that risk. If it appears that no feasible standard can adequately protect the public, the Commission could declare that It is a banned hazardous rop duct (Sec. 8 CPSA). Where the Commission concludes that a product presents an imminent and unreasonable risk of death, serious illness, or severe personal injury, the Commission may file in a U.S. district court an action for a court declaration that a product is an imminent hazard (Sec. 12 CPSA). In the case of asbestos exposure, the injury would not be immediate but may be impending because of the long latency period. In fact, this chronic hazard area is one that is receiving new emphasis in the Commission. By themselves, our methods of empha- sizing the acute injuries and toxicities by national surveys of emergency room injuries appear inadequate for chronic hazard evaluation and regulation. Chronic hazard information most frequently comes from retrospective epidemiologicai occupational studies, case reports, and animal studies. Chronic hazards are the most silent type of hazards because the consumer is unknowingly exposed to chemical products which have hitherto been assumed safe. A partial list of chronic hazards on which the Commission has taken action to regulate or propose to regulate includes: Lead (in paint) Vinyl Chloride (as an aerosol propellant) TRIS (flame retardant) CFC's Chlorofluorocarbons (as aerosol propellants) Asbestos (fireplace embers, patching compounds) Petitions - One other factor is important in describing the sequence of events in CPSC's regulatory process. Interested persons may petition the Commission to commence proceedings for the issuance, amendment, or revocation of a rule under any Act administered by the Commission. It was through the petition process that the Commission's regulatory sequence began for asbestos-containing products. The Commission has considered three petitions [11,15,18] requesting it to ban consumer patching compounds and artificial embers and ash containing respirable, free-form asbestos. The request on artificial embers and ash, received in November 1975, was initially treated 452

Cs as a`consumer complaint, and the staff conducted follow-up investigation on the complaint. Subsequently, in July 1976 and March 1977, two petitions were received seeking bans of free-form asbestos-containing consumer patching compounds. The Commission then proceeded to investigate: (a) what hazard was actually associated with these products, (b) how the hazard could be.reduced with maximum compliance and minimum disruption, and in addition, to evaluate (c) what future protective rules should be made for public safety. Non-Occupational Exposure The first step was to decide whether consumers could be exposed to asbestos. Direct and indirect evidence exists that individuals, other than those working directly with asbestos minerals, are being exposed to asbestos. For example, asbestos fibers have been demonstrated at autopsy in the lungs of persons who were not occupationally exposed [6,7,14,23]. Substantial evidence also exists that human lungs may harbor thousands of fibers, some of which are chrysotile. However, the number of asbestiform fibers found in non-occupationally exposed individuals is relatively small compared with the numbers in occupationally exposed individuals [19J. The next step was to decide if there was any risk of injury to exposed consumers. Since the reports from emergency rooms were not suitable for our needs, other d4ta were sought. Indirect evidence of asbestos-caused adverse health effects was provided by epidemiological studies which showed malignant mesotheliomas, rare in the general population, to be associated with individuals with no occupational exposure to asbestos, but who lived in the vicinity of the asbestos fields or mines [2,12,24]. Another investigation of the extent of asbestos exposure associated with 42 diagnosed mesothelioma cases was conducted in southeastern Pennsylvania. Of these, 8 were neighborhood exposures and 10 had questionable exposure. Among this group was a 14 year old boy who alledgedly helped his father replace plasterboard during extensive home remodeling [8]. A short exposure (according to the report) of mixing and' applying asbestos cement insulation to a boiler in a consumer's home has also alledgedly caused mesothelioma [8]. It has also been suggested that inhalation of small numbers of asbestos fibers over a long period of time could result in focal concentrations at the lung bases, possibly reaching fibrogenic or carcinogenic concentrations [23]. Next, we had to decide just what type of products had asbestos available for respira- tion, i.e., free vs. bound fiber. In numerous products the fibers are tightly bound to the matrix or are encapsulated. A potential health risk occurs when asbestos fibers become- airborne, such as by mixing, sanding, or cleanup operations when using asbestos- containing patching compounds. However, in terms of risk to the public health, a single individual engaged in such a process may inadvertently expose other individuals in the vicinity.- The importance to such "bystander" exposure has been emphasized in several reports [1,9,17,20] and we had to consider this also. Risk Assessment Another big question: how much risk of injury is associated with the product? A model for lifetime risk assessment of death from respiratory cancer due to consumer use of asbestos-containing wall-taping compounds was prepared by one of the authors (S.B.). In order to compute such a risk assessment for the use of asbestos-containing wall-joint compounds, many assumptions had to be made. The model selected for analysis was that developed by Enterline and Henderson [4], which in turn was derived from data on amosite 453 2063105241

asbestos factory workens. and asbestos insulation workers [20]. Measurements of asbestos fibers longer than 5 microns from work with wall-taping compounds were taken from data provided by Rohl, Langer, Selikoff, and Nicholson, [17]. Projections of consumer use and exposure were determined and age central death rates from respiratory cancer based on the 1970-71 vital statistics of the United States were utilized. The assumptions used in the risk assessment model are presented below: (a) The dose-response relationship between asbestos and lung cancer is linear [4]. This hypothesis assumes no threshold. (b) Time to tumor is dependent on dose and can be described by a Tog normal distribution with median time to tumor t: t=98.65(') 0 1/3 where D= 8-hour time weighted average dose in fibers/cc and a log standard deviation of 1.5. (Enteriine and Henderson, 1976, (4] based on Jones and Grindon, 1975 [5]). (c) Competing risks of death for the first 40 years following exposure are considered to be normal. (d) Risk of asbestos caused death after the first 40 years following exposure is considered to be zero. (e) Effect of dose is cumulative and is assumed to have the same effect as if that dose had been accumulated in the first year of exposure. (f) Intermittent exposure with occasional high peaks has the same cumulative effect as continuous exposure at double the dose [3,4]. While the assumptions (a through f) may seem at first unclear, the total effect is to present a cumulative dose-response curve of the form log dose-log,response. This is shown in figure 1. Explanation of how these figures were derived is given below. It is emphasized, however, that this model is to be used for low exposure estimates. It is not designed to fit data for high or long-term exposure data. 454

10,000 1,000 ~E U U N L b 100 o .- ~.J L ~ v v 1D Cy E Y G) W J 0 log Y= 2.081+2.513 log X r = .992 X = Average Daily Dose f/cc (log scale) Figure 1. Response vs. dose for low level asbestos. Exposure: Asbestos induced respiratory cancer deaths per million lifetime vs. daily exposure (f/cc) for 1 year. Estimates based on the model. Derivation of Total Cases Caused Py Asbestos Exposure Besides the assumptions above, the major data used to estimate the total cancer deaths attributable to dose were the Selikoff data on 294 factory workers who had been exposed to asbestos for 3-11 months during the years 1941-45 [20]. Estimates of the concentration of asbestos dust during this period averaged 30 f/cc. Since the average exposure was only 5/8 year, the equivalent concentration was figured at 18.75 f/cc/day on a 1-year basis. By assumption (b), the median time to death from respiratory cancer is 37.1 years. Also, by assumption (b) the log normal distribution shows that for the 28 years of follow-up used in the Selikoff paper only 24.4 percent of these deaths would have occurred. Since the adjusted relative risk of these workers was 2.95 [4], and the age central death rate from respiratory cancer (ages 35+) was 850/million, the number of respiratory deaths which could have been caused by the asbestos exposure was the solution to: 28(.000850 + .244 X) = 2.95 28(. 000850) or X=.190205 or 190,205 deaths/million. But, since only 40 years of exposure are considered (assumptions c and d), assumption (b) allows only 57.3 percent or 109,000 lifetime cancer respiratory deaths per million exposed. By assumption (a), the number of potential cases by dose can then be calculated and risk estimates can be derived from these. This is shown in Table 1, along with the calculated relative risks. Here it can be seen that excess deaths and relative risks do not increase linearly with increasing dose but in a geometric manner. 455 2063105243

Table 1. Lifetime (40'years) risk estimates of respiratory cancer deaths by dose for a 1-year equivalent exposure. Median latent periods and relative risks are included. (1) (2) (3) (4) (5) (6) 8-hour Avg. Latent Potential Proportion Asbestos Relative Daily Expo- Periods Cases/ Developed Induced Risk sure Level D Years 1 Million in 40 years Respir. (5)+850x40 f/cc t=98.65(p)1/3 (see text) (log normal) Cancer 850x40 Deaths/ (3)x(4) .5 124.3 5,072 .0026 13 1.00038 1 98.6 10,145 .0130 132 1.00388 2 78.3 20,290 .0488 • 990 1.02912 4 62.1 40,578 .1488 6,038 1.17759 8 49.3 81,155 .3030 24,590 1.72324 16 39.1 162,310 .4776 77,519 3.27997 18.75 37.1 190,205 .5727 109,000 4.20588 Estimates of Exposure Levels of Consumer Users of Wall Taping Compounds Rohl [17] measured peak fiber concentrations of ten drywall taping compounds during sanding, dry mixing, and floor sweeping. The average peaks were as high as 47 f/cc with the highest individual peak of 59 f/cc. Based on these peaks the 8-hour time weighted average was estimated as 10 f/cc. Taken with assumption (f) that high intermittent exposure was estimated to have doubled the effect of continuous exposure, this estimate was increased to 20 f/cc. If there are four uses projected per year, the estimate of yearly equivalent is: 20 f/ccys 200 days yaar 4 f/cc/day for 1 year Thus, based on the results of the model, Table 1, it is estimated that 4 heavy exposures by consumers in one year will cause an additional 10 lifetime respiratory cancer death/million. Continued use for five years will, by assumption (e), raise that estimate to 990 deaths per million (see Table 1). No quantitative risk assessment was made for asbestos exposure from the artificial embers and ash since th:re are no known measurements of the airborne fiber content. It can be assumed, however, that whatever air concentrations are present, they expose the home occupant to a continuous inhalation of free fibers vs. only intermittent exposure for the wall-taping compounds. The risk from these embers and ashes, therefore, may be considered at least as high as that from the wall-taping compounds. In our opinion the greatest period of risk for embers, ashes, and patching compounds is both during the application and removal processes. Re9ulatory Decision Since we considered this risk of injury too high, a safety rule was obviously called for. Because of possible cumulative effects of exposure to respirable asbestos, we felt that total exposure should be kept as low as possible and it was, therefore, decided to issue a regulation. 456

(cs The options available to the Commission were: (a) under the Federal Hazardous Substances Act (FHSA) as "banned hazardous substances". (b) under Section 8, CPSA, a proposal to ban manufacture, sale, and distribution. The Commission decided to issue a ban under Section 8 of CPSA. CPSA Ban The Commission decided that it was in the public interest to propose the ban of consumer patching compounds and emberizing materials containing respirable free-form asbestos under the CPSA (Sec. 30(d), CPSA), although the petitions were submitted under FHSA and the risk of injury could be eliminated or reduced to a sufficient extent under the FHSA. The Commission believes that the rulemaking proceedings under the FHSA are likely to be lengthy and resource consuming and that those proceedings could make it more difficult for interested persons to participate. On the other hand, Section 8 of the CPSA, under which a CPSA banning rule would be issued, provides for a period wherein all persons affected by the proposed banning action can submit written comments. An opportunity for oral presentation of data, views, or arguments, is also provided. During this period, any additional information or data that might better define the nature or degree of the hazard associated with the affected products may be brought to the Commission's attention for consideration prior to the promulgation of a final rule. Removal and Disposal While the banning rule is considered, the removal and disposal problems associated with artificial asbestos ash/embers will also have to be addressed. The disposal of the material in the homes of consumers poses a difficult problem. The Commission has been requested to declare fireplace emberizing materials containing asbestos "to be imminently hazardous consumer products," and to direct manufacturers of such products to remove them from the homes of consumers.• The Commission solicited the advice of experts as to whether consumers could safely remove the asbestos "ashes" from their own fireplaces. While the consensus is that, exercising caution in accordance with available expert advice, they could. However, there was some contradiction among the experts as to how it should be done. The Commission, therefore, will consider various removal procedures before issuing advice to the public. Guidelines on safe removal may mention disposal instructions for unused patching compounds. The Commission's staff believes that their removal may pose no hazard since, unlike the "ashes", this material is not loosely scattered. The asbestos patching material on the walls is assumed to have already been suitably covered and should not create an unacceptable risk. Future Commission Actions on Asbestos Asbestos in consumer products has been established as the Commission's highest priority project for FY 78. This project will assess the potential hazard of other consumer products containing asbestos. The asbestos content of a given product is not necessarily the sole criterion of that product's relative health risk. A potential hazard occurs when asbestos fibers become airborne and can be inhaled. Thus, the Commission's concern is to determine what other consumer products contain asbestos fibers which can readily become airborne under normal use conditions. The Commission will then decide if additional rulemaking is required for the protection of the consumer. 457 2063105245

References [1] Anderson, H. A., Lisis, R., Daum, S. M., Fischbein, A. S. and Selikoff, 1. J., Household- Contact Asbestos Neoplastic Risk, Ann. N. Y. Acad. Sci., 271, 311-323 (1976). [2] Sarow, M. A., Conston, L. L., Livornes, L. L., Schalet, N., Mesothelioma and its Association with Asbestosis, J.A.M.A., 201(8), 93-97 (1967). [3] Enterline, P. E., DeCoufle, P., Henderson, V., Mortality in Relation to National Exposure in the Asbestos Industry, JDM, 14(12), 897-903 (Dec. 1972). [4] Enterline, P., Henderson, V., A Model for Extrapolating to Low Levels of Asbestos Exposure. Presented at Conference on Problems of Extrapolating the Results of Laboratory Animal Data to Man and Extrapolating the Results from High Dose Level Experiments to Low Dose Level Exposure, Pinehurst, NC (March 11, 1976). [5] Jones, H. B., Grindon, A., Environmental Factors in the Origin of Cancer and Estima- tion of the Possible Hazard to Man, Food, Cosmet. Toxicol. , 18, 251-268 (1975). [6] Langer, A. M., Ashely, R., Baden, V., Berkley, C., Hammond, E. C., Mackler, A. D., Maggiore, C. J., Nicholson, W. J., Rohl, A. N., Rubin, I. B., Sastre, A., and Selikoff, 1. J., Identification of Asbestos in Human Tissues, J. Occup. Med., 15(3), 287-295 (March 1973). [7] Langer, A. M., Selikoff, I. J., and Sastre, A., Chrysotile Asbestos in the Lungs of Persons in New York City, Arch. Environ. Health, 14, 559-563 (April 1967). [8] Lieben, J., and Pistawka, H., Mesothelioma and Asbestos Exposure, Arch. Environ. Health, 22, 559-563 (April 1967). [9] Lillington, G. A., Conjugal Malignant Mesothelioma, New Enc1. J.Med., 291(11), 583- 584 (September 1974). [10] McOonald, J. C., McDonald, A. D., Gibbs, G. W., The Health of Chrysotile Asbestos Mine and Mill Workers of Quebec, Arch Environ. Health, 28, 61 (1974). [11] Natural Resources Defense Council (NRDC) Petition, HP 76-18, Consumer Patching Compounds Containing Respirable Asbestos (July 15, 1976). (12] Newhouse, M. L. and Thompson, H., Mesothelioma of Pleura and Peritoneum Following Exposure to Asbestos in the London Area, Brit. J. of Indust. Med., 22, 261-269 (1965). [13] Nicholson, W. J.;: Case Study 1: Asbestos--The TLV Approach. Occupational Carcinogenesis, Annals of the New York Academy of Sciences, Vol. 271, 152-169 (May 1976). [14] Pooley, F. D., Oldhas, P. D., Um, C. H., and Wagner, J. C., The Detection of Asbestos in Tissues, Pneumoconiosis Proceedings of the International Conference, 1969, Cape Town: H. A. Shapiro, Ed., Oxford Univ. Press, 108-116 (1970). [15] Public Citizens Health Research Group (HRG) Petition, HP 77-9, Patching Compounds with Tremolitic Talc Containing Asbestos Fibers (Asbestiform Tremolite) (February 9, 1977). [16] Public Law 92-573; 15 U.S.C. 2051, 92nd Congress, 5. 3419, October 27, 1972. Consumer Product Safety Act. [17] Rohi, A. N., Langer, A. M., Selikoff, 1. J. and Nicholson, W. J., Exposure to Asbestos in the Use of Consumer Spackling, Patching, and Taping Compounds, Science, 189, 551- 553 (1975). [18] Scott, Ms. Rachel, joined by Environmental Defense Fund (EDF), HP 77-11, Artificial Fireplace Ash Containing Respirable Free-Form Asbestos (April 15, 1977). 458

[19]-Selikoff, I. J. and Hammond, E. C., Asbestos Bodies in the N.Y. Population in Two Periods of Time, Pneumoconiosis Proceedings of the International Conference, 1969, Cape Town, H. A. Shapiro, Ed., 99-105 (1970). , [20] Selikoff, 1. J., Hammond, E. C., Seidman, H: Cancer Risk of Insulation Workers in the United States. IARC, Biological Effects of Asbestos, Lyon, France, (1973). [21] Selikoff, I. J. and Hammond, E. C., III. Community Effects of Nonoccupational Environmental Asbestos Exposure, A.J.P.H., 58(9), 1658-1666 (September 1968). [22] Selikoff, I. J., Bader, R. A., Bader, M. E., Churg, J., and Hammond, E. C., Editorial: Asbestosis and Neoplasia; The Amer. J. of Medicine, 42(4), 487-496 (April 1967). [23] Thomson, J. G., Asbestos and the Urban Dweller, Ann. N.Y. Academy of Sci. , 123, 196-214 (1965). [24] Wagner, J. C., Sleggs, C. A., and Marchand, P., Diffuse Pleural Mesothelioma and Asbestos Exposure in the Northwestern Cape Province, Brit. J. Indust. Med. 17, 260- 271 (1960). Discussion J. LEINEWEBER: I'd like to make the statement that some of the appiications of asbestos fiber that you are discussing here are considered among those of us i`n the asbestos industry as applications that are not necessary and can be eliminated frdm the workplace and from the environment. I wasn't able to follow several of the arguments you were giving in terms of your risk assessment, and I think for the purposes of bringing a discussion like this to a reasonable conclusion, I for one will appreciate seeing some of this and maybe having an opportunity to rebut it before the final publications of these proceedings are out-is that possible? R. HEHIR: It certainly is. All the information that we have on risk assessment and all the briefing packages are in the Office of the Secretary of the Commission. They are located at 1111 18th Street, and Mr. Richard Rapp or Miss Sadie Dunn would be very happy to provide all the pertinent information I've discussed here, and any of the additional materials which are submitted should go to that particular office so it can be considered in the rulemaking process. C. COOPER: I thought that the presentation of the risk assessment was a fascinating exercise, and I too would like to see the details by which these numbers were attained. I thought I heard the figure of an average exposure for a year of 0.4 fibers per cc arising out of four applications. HEHIR: Yes. COOPER: That seems to be an extraordinarily high number to arrive at from four applications when compared with the exposures that we observed in insulating workers, for example, who work with insulating materials around the clock. We found average exposures of maybe ten times that for men who work with asbestos year around. It seems to me that your number is an unusually high average concentration for a year, but I am not questioning it but I would like to see some figures from which it was derived. HEHIR: Dr. Cooper, I'm sure you'11 have an opportunity to see the figures. As a matter of fact we received additional information from other people. As I have told you initially, the material on patching compounds was from the publication by Rohl, Langer, Nicholson, and Selikoff, and that was our jumping off point. For example, that was the data we utilized and we came up with the figure based on six assumptions. I'm sorry I was not able to have a slide of the table and the figure and some other mathematical calculations to show you how they are derived; however, the paper will be published and the information is readily available at this point. 459 2063105247

st COOPER: I do think that this is an interesting approach to this problem and I'm very anxious to see how it was reached. M. BROWNSTEIN: Two things: you have not mentioned anything about the time table for this proposed ban. I wonder if you could go into that at all. The other area is, how is it planned to differentiate between the products that are intended for the home handy man, or will be used by the home handy man, and those which are used by the construction industry? HEHIR: Well, we regulate products that come into the home that are sold to the consumer. We don't regulate anything that might be considered an occupational hazard. As far as the risk assessment, and the deliberations on time tables, that is in the hands of the general council. I can't tell you how long it will take; a prudent man could contem- plate a year. A person dealing with government knows that the wheels of progress in this particular regulatory forum move ever so slowly; probably in a few years. Since these are my own expressed opinions, I don't feel compelled to tell you that the Commission may have a different view. BROWNSTEIN: Just to continue on that restriction that you only deal with consumer products, my question was more on how are you planning to differentiate between what is a consumer product? Let's say a building supply store, this sort of thing where you find both groups going to get products from the same outfit. HEHIR: I find it difficult for similar regulatory agency representatives to ask a question like that. The Act spells out very clearly we handle consumer products which are not food, drugs, cosmetics, or economic poisons; now the interpretation really centers on what constitutes a consumer product. If you can buy it in a hardware store, then we consider it a consumer product. If, however, the manufacturer regulates from point of sale to distribution and can so demonstrate such regulations and such control then, quite frankly, we might not have jurisdiction. ROSS: Do you have any _data on the health of professional plasterers and also professionals in other similar areas, like cement workers? HEHIR: Dr. Ross - I personally don't, but I'm sure by the end of our rulemaking procedures we will have that kind of information. 460