Document QX9Zbv8DMRO4Mk68drzB0QoQ6

MEMORANDUM -' - . "rv -jcc- eZAUi. BKI'AKTMENT. ov HEALTH, EDUCATION/'AND welfare u::;' N-E . .'''i,uftU(; i.'at.'i Szrvick-u'RMAG- . . CF.NTiiR rou rusCA^r. co.vrk^" T: '"; ' i :Assistant: Secretary of iMbor 'v - Occupational Safety and Health Administration Departmenl* of Labor v' -- ' k *"^'^7^::'- tow ' A-;' DirectorNational.--Institute for V'Occupational Safety,and Health- " 'R." UR R.RV. ' R. ' - JBJECT: Recounaetidcd Occupatiohai Health Standard for the Manufacture of' "R .^-.Synthetic Polymer .from Vinyl Chloride ' ---; ' -;RMR-. - R u'.;-:v - R- V - .1 "; : R'"RR.- '' On .January 22,- 1974, representatives from the B; F. Goodrich Chemical .M Company informed KIOSK that the deaths of several employees of their . Louibville, Kentucky, plant might have been related to occupational . R . .exposures [ An immediate industrial hygiene'walk--through' survey of "the R facility was conducted by NIOSH and resulted in developing and transmit ting to affected, companies recommendations for precautionary monitoring and control procedures for polymerization processes involving vinyl chloride. On February 1, 1974, NIOSH/CDC conducted a briefing for other Federal agencies with health research responsibilities at which it was disclosed that four employees of the plant in questiou had died of angiosarcoma of the liver. Because of the extremely 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 was further concluded that this disease was associated with the manufacture of polyvinyl chloride end that vinyl chloride was the prime etiological candidate in producing the disease. NIOSH, with the assistance of expert consultants from both industry and organized labor, began development of a recommended occupational health standard. These and other activities were discussed in more detail at the OSHA Informal Fact-Finding Hearing on Possible Hazards of. Vinyl Chloride Manufacture and Use 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 angiosarcoma of the liver and other organs, as 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. Goodrich workers. / \ \ i rI 1 I see 3-0914 ,,l*aC 2 - Assistant* Secretary.'of^Labor, OSHA ' ' , :';Vr; Since the.pSllA^eari^^NIp^t^as ^leairned ,of ^t^JLeasjt.l f ivc;adlditioniik^*'^( cases of angiosarcoma of the livef/' Two of'these cases were diagnosed in the current working population at the same 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. . - .V; . Although vinyl chloride must .be considered as a. carcinogenic*'agent, . "the immediate problem appeared to'be concentrated in polymerization ... . facilities. : Consequently, the attached NIOSH recommended standard .. ' only applies to'such' operations.;' This is not to say, however, that . appropriate standards, should not be developed-for other, exposures .: to the-basic chemical.-.' NIOSH is implementing further evaluation . - of.the.data,.coupled with field .observations, to determine exposure - potentials in'pre- and post-polymerization -operations. You will ' . ^ ^ be;informed as-further data^and plans are developed. ~-.- \ As previously indicated, NIOSH considers this to be a most serious -problem^and strongly urges that expedited rulemaking be implemented by OSHA to insure that the health of exposed workers is promptly and adequately safeguarded.- We feel that, except where employers experience problems in obtaining air 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 two weeks could also be implemented immediately with the possibility that some employers would need a short period of time for their medical staff or consultants to make arrangements for any special laboratory tests. You should be aware that the consultants from industry who worked with us proposed that the recommended standard contain the concept of an allowable "working level" for vinyl chloride gas in the atmosphere, which they identified as a time weighted average of 50 ppm. They recommended that where workers were exposed to concentrations in excess of this level they should wear air-supplied respirators. This concept of an allowable "working level" might seem justifiable in that Professor Maltoni found no liver tumors at 50 ppm, but there is the possibility that tumors might 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 with 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, we rejected the concept of a threshold limit for vinyl chloride gas in the atmosphere. see 3-0915 Page 3 -- Assistant Secretary of Labor, OSHA ^Consequently ^^our "recommeridatioris^as'r"coutained :n tKe''attached - document "!~"r arc such that where any employee is exposed to measurable concentrations of vinyl chloride, as determined by the recommended sampling and analytical method, he shall wear an air supplied respirator, This recommendation is based on some preliminary information that the standard chemical cartridge respirators 'are"inefficient in protecting against vinyl chloride. . NIOSH. f-is-implementing a study to-evaluate the-degree of protection.afforded by.''.' different-type's^of "respirators "using vinyl .chloride as the test. gas. :4`As. ' ^information'becomes available, it will be forwarded to OSHA as recoin- . ''mendations for-alternative respirator usage. The employer ;is also'required to': develop a'Cpntrol' Plan' to "reduce airborne' concentrations .`of- vinyl trichloride .to . levels .hot detectable by the recommended method ' .As you will no^e in reviewing the recommended standard," there are V *' ^references, to the, "sampling and analytical method recommended by the: . Director This method, in the form.of a compliance sampling data sheet, will be forwarded to OSHA within a week.' We`now estimate that the level of sensitivity of our recommended method will be:around one part per - million, specifically for vinyl chloride. The Office of Research and Standards Development, which is directed by Mr. 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 Mr. Rose. g.yt/, Attachment Marcus M. Key, M.D aAssistant Surgeon General l see 3-0916