Document x1Vnzw3o7jbOM7KErVnM0LJj0

ilANDUMJLvt/J,. * DHI'AUT Ml.bwT Or JXU.TJI. EDUCATION*. AM) WJ.bVAi'.). MSkiir. lor. !! W UVii.l. am. i Assistant Sccrttr.ty of Labor imi* Oteupstlonol Scfoty and Health Administration Lcpartvjcnt of J,,*.r.-or Jj *l3/4 IU.OM : Director* Kational Institute for Occupational Safety and Health 'SUBJECT: BecomS-ended Occupational Health Standard for the Kanufacturc of Synthetic Polymer rc>a Vinyl Chloride On January 22* 1974, representatives from the B`. F. Goodrich Chemical Conpany informed KIOSH that the deaths of several employees of their Louisville, Kentucky, plant eight have been related to occupntier.nl exposures* 7m imrediete industrial hygiene walk-through survey of the facility was conducted by KICSH end resulted in developing and transmit" ting to affected companies recorser.dctaor.s for precautionary uonitoring oral control procedures for uoiyacrisation processes involving vinyl chloride. On February 1, 1S74, K10SK/CCC conducted a briefing for other Federal agencies vith health research responsibilities at which it vas disclosed thet four employees of the plant in question had died of angiosarcoma of the liver, because o the cxtrcrly low incidence of this disease, estimated to be on the order of 20 to 30 deaths per year in the United States, the history of four cases in a five-year period in one plant was considered of`great importance. It was .concluded at the briefing that a new occupational cancer had been discovered: angiosarcoma of the liver. It vr.s further concluded that this disease kss associated with the manufacture of polyvinyl cbicricc and that vinyl chloride was the prime etiological candidate in producing the disease. KIDSH, with the assistance of expert consultants from both industry . and organized labor, began development of a recommended occupational health standard. These end other activities uerc discussed in more detail at the 0?iA Informal Fact-Finding Hearing on Possible Hazards of Vinyl Chloride KenufsctuTc and l-sc on February 15, 1974. It was also during this Hearing that Professor Cesare Maltoni of bologna Italy, presented the preliminary results of his research which showed > induction of nngiosarcor-i of the liver ana other organs, os well as .the production of other cancers in rats exposed to vinyl chloride.. The results of these studies identify vinyl chloride as a carcinogen and further confirm its role in inducing the cancers observed in the B. F. Ceodrich workers. <* i i ii : i lf * i--'i i t I il tf*' i5 Ui. DTH 000013640! * ,*c 2 - Assistant Secretary of ujor, 05HA Since the OSHA Hearing, MOS11 has learned of at least five additional cases of nngiosorcoisa of the liver. Tt:o of these cases were diagnosed in the current working population at the cane Louisville facility, while the other three involved deceased workers, one each from the Louisville facility, Union Carbide's South Charlestown plant, and Goodyear's Niagara plant. Although vinyl chloride must bo considered as a carcinogenic agent, the immediate proUen appeared to be concentrated in polyneriration facilities. Consequently, the attached HJDS3J recommended standard only app.lies to such operations. This is not to say, however, that appropriate standards should nor be developed for other exposures to the basic chemical. HICSH is implementing further evaluation of the data, coupled with field observations, to determine exposure potentials in pre-.and pest-polymerization operations. You will be informed as further data and plans arc developed. As previously indicated, HIOSH considers this to be a cost serious problem and strongly urges that expedited rulemaking be implemented by OSHA to insure that the health of exposed worker is promptly and adequately safeguarded. Vo feel that, extent where employers experience problems in obtaining adr supplied respirators or environmental monitoring equipment/ the attached recommendations can be implemented as soon as a standard is promulgated. The medical surveillance requirements which will be supplied in one to ti?o weeks could aiso be implemented immediately vith the possibility that sobs employers would need a shoTt period of lice for their medical staff or consultants to make arrangements for any special laboratory tests. You should be aware that the consultant s from industry who worked with vs proposed that the rccomrcnded standard contain the concept of an allowable "working level" for- vinyl chloride gas in the atmosphere, which they identified as a timt weighted average of 50 ppra. They, recommended that where workers were exposed to concentrations in excess of this level they should wear air-supplied respirators. This concept of sn allowable "working level" might seen justifiable in that 1'rofessor Haltoni found no liver tumors at 50 ppn, but there is the possibility that tumors night have been produced if a larger number of animals had been exposed at that concentration! Based on theoretical considerations, there is probably no threshold for carcinogenesis although it is possible that vith very low Concentrations, the latency period might be extended beyond the life expectancy. *In view of these considerations and our inability to describe a safe exposure level as required in section 20(a)(3) of the Occupational Safety and Health Act, vc rejected the concept of a threshold limit for vinyl chloride gas in the atmosphere. . DTH 000013541 - Fane 3 -- Assistant Secretary of Labor, OSJIA Consequently, our recommendations as contained in the attached document w to based on sons preliminary information that the standard chemical car trie' respirators are inefficient in protecting against vinyl chloride. HICSU is implementing a study to evaluate the degree of protection afforded by , different types of respirators using vinyl chloride os the test gas. As information becomes available, it will be forwarded to OSHA ns recom mendations for alternative respirator usage. The employer is also required to develop a Control Flan to reduce airborne concentrations of vinyl chloride to levels not detectable by the recosrsended method. As you viil note in reviewing the recommended standard, there are . references to the "sampling and analytical method recotmended by the Director." This method, in the fora of a compliance sampling data sheet, : vill be forwarded to OSHA within a week. T?e now estimate that the level of sensitivity of our recommended method vill be around one part per . million, specifically for vinyl chloride. The Office of Research and Standards Development, which is directed by v. Kr. Vernon E. Rose, has had lead responsibility in developing this recommended standard. As your professional staff review and evaluate our document, questions or requests for additional information should be directed to hr. Rose. Attachment ' harcus M, Key, h.D; / Assistant Surgeon General DTH 000013542