Document RpqzzVrDzd7LzVkagmxa09XaV

Federal Register / Vol. 51, No. 119 / Friday, June.20, 1986 '/ Rules and Regulations 22647 is estimated to be 3 excess deaths per Seminario:. . . (I)n conducting risk The first element established by the ? 1.000 workers. assessments, in many cases, those risk Supreme Court's Benzene decision (IUD : Additionally, OSHA estimated the assessments will be based not on v. API448 U.S.) for determining the } . risk (i.c., the predicted incidence) of asbestosis morbidity at the existing permissible exposure level of 2 f/cc. OSHA's best estimate is based on the results of a high-quality study of the epidemiologic studies, but, indeed, on animal studies. Is that correct? Nicholson: Often, that may be our only recourse, in other studies. . . jl]f one reviews the (International Agency for Research on Cancer Monographs) significance of risk of material impairment--that a significant risk existed at the existing permissible exposure limit of 2 f/cc--is thus clearly and decisively established by OSHA's incidence of compensable (certified) . . . volumes 1-26 that have evaluated risk assessment and by the Insidious asbestosis at an asbestos-cement human carcinogens, they have, only deemed nature of asbestos-related disease. In factory (Ex. 84-240). Based on 18 agents or work processes to have making a determination thal this risk is cumulative exposure data and assuming sufficient data for which one could . ... significant, OSHA relies, in part, upon a linear model, OSHA estimates that the establish carcinogenicity (in humans), let the Supreme Court's indication of when incidence of asbestosis is 50 cases per alone provide quantitative risk assessments a reasonable person might consider a- 1.000 workers exposed for 45 years to 2 . in hypothetical circumstances. So our human. risk significant and take steps to f/cc. i In the April notice, OSHA data are very scanty for most agents (Tr. 6/19 pp. 134-135). decrease that risk. OSHA Finds, as . indicated by the risk assessment, that characterized the basis for determining Similarly, Dr. Hans Weill commented the existing standard of 2 f/cc would that a significant risk exists at the 2 f/cc that ". . . we know of no other permit an excess cancer mortality risk of level as being "particularly strong" (49 occupational disease for which more 64 deaths per 1,000 employees and an FR14120). This'assessment was based complete exposure-response data are estimated asbestosis incidence of 50 on the reliance on occupational available from human population cases per 1,000 employees exposed for a epidemiological studies for the studies" (Ex. 99, p. 30). In its.post- working lifetime; this excess risk must quantitative risk assessment, the high hearing submission, Organization be considered significant and quality of the scientific data, the Resources Counselors, Inc. stated that unacceptable using virtually any consistent estimates of dose-response "(ajsbestos is a proven carcinogen of reasonable basis for making such a among the various studies.used, and the long standing, Volumes of scientific determination. OSHA also Finds that the appropriateness of the models and work attest to the fact that asbestos excess risk of cancer mortality resulting methods employed in the risk produces both lung cancer iand from 20 years of exposure to asbestos assessment. Review of the record mesothelioma" (Ex. 127-A, p. 2). These (44 excess deaths/1,000 workers) is also i : .1 evidence submitted since publication of the April notice has served to reinforce OSHA's confidence in the data and. comments, and-the evidence contained in the record on health effects from asbestos exposure (see Section IV) significant. As pointed out in the April notice (49 FR 14120), the risk from asbestos exposure at the 2 f/cc level has ..S analysis underlying the determination reaffirm OSHA's belief that the data also been acknowledged as being that a significant risk exists at the used in the quantitative risk assessment unacceptable by other governments. existing permissible exposure level for are of unusually high quality. (Exs. 84-378,84-379). The level of risk asbestos. Regarding the quality of the data, several commenters stated that the health evidence for asbestos-related disease is far more convincing, due to the quality and number of human A review of the rulemaking record has also strengthened OSHA'b belief that it used the most appropriate models to calculate the risk. To estimate the risk for lung cancer, OSHA used a linear dose-response model based on evidence estimated by OSHA at the existing permissible exposure limit is also comparable to the estimated risks for other toxic substances that OSHA has regulated or proposed to regulate in the past. studies available, than are health effects found in several epidemiologic studies In accordance with the second data for any other hazardous substance. This point was emphasized at the informal hearing by Dr. Nicholson under that examined lung cancer mortality in relation to cumulative asbestos exposure (Exs. 84-43, 84-59,84-35), and element of the Supreme Court's Benzene decision on the determination of signiFicant risk, OSHA has determined cross-examination by Ms. Seminario of on the use of a linear model by several that reducing the permissible exposure the AFUCIO: other investigators (Exs. 85-22,64-210, limit for.asbestos to 0.2 f/cc is Seminario: Would you say that (the data for asbestos). . . Is generally better and 84-243, 82-2, 84-180, 84-256. 321). For mesothelioma, OSHA used an absolute reasonably necessary to reduce the cancer mortality risk from exposure to more complete than. . . (for other toxic- risk model, which has been used or asbestos. OSHA's risk assessment substances]? suggested by a number of other authors shows that lowering the permissible Nicholson: I don't even think there's a ' comparison. The data .for asbestos are so much more extensive than those of other toxic substances in the workplace. It's a wide divergence. . ' Seminario:... Basically, you have asbestos with a lot of studies and a lot of. information, and a great number of workers . to estimate the risk of mesothelioma (Exs. 84-252, 84-385, 84-342, 84-87,132, 84-138). In response to record comments submitted after publication of the April notice, OSHA revised the individual potency factors for lung cancer (KJ and mesothelioma (KM) for some of these exposure limit from 2 f/cc to 0.2 f/cc reduces the asbestos related cancer mortality risk from lifetime exposure from 64 deaths per 1,000 workers to 6.7 deaths per 1,000 workers: this corresponds to a 90 percent reduction In the risk. The asbestos-related cancer . . included as subjects in those studies . . . epidemiological studies (see Section V risk is also reduced by 90 percent, from compared to less complete data for other of this preamble). These adjustments 44 deaths to 4.5 deaths per 1,000 toxic substances? Nicholson: Yes. - Seminario:. , . (l]t realty is a much more complete data base for conducting risk assessment and making estimates [of risk) than you would hove for any other, substance? Nicholson: Yes. it is had little effect oh the overall XL of 0.01 employees, for a 20-year exposure, and Km of IX10'`originally proposed by duration..!! is estimated that the OSHA for the combined data sets. ' incidence of asbestosis for workers OSHA believes that this finding reflects exposed for a working lifetime under the the reasonableness of the risk estimates new standard will fall by 90 percent, for lung cancer and mesothelioma set from 50 cases to 5 cases per 1.000 . forth in the April notice. employees. As these figures show. GLEASON-000895