Document JrJMnZXBNYZ8M4D03GmLRvrjX

MAR 1 61989 ' JfVIC -1 ai - ' March 13, 1989 To: VDC Panel Re: OSHA "Z-Table" Rule for VDC For your information, attached is a review of the final Z-Table regulation providing exposure limits for VDC for possible legal issues, as prepared by Mr. Bruce Dickson. Sincerely yours, Robert R. Romano, Ph.D. Associate Director, Special Programs Division & Manager, Vinylidene Chloride Program SL 064977 Pai'l. Hastings, .Janofsky & Walker , ,.-,---.3 , - - _ - .. _ ;" 3 sOH Af iO 2 2 3 3 33S z _ _ j j. s March 7, 1939 aT'^nTa off ce CEOOGiA-PACiFiC CntR 33 bCaCh''SEE: 3TSEEZ n E ATLANTA OEOBG A 3C3C3 TELEPHONE '*C4I 539-3900 CONNEC*'C'jT CFF'CE ONE CANTERBl.R GSEEN STAMFCRO. OONNECT'O-' 3600 'ElEPhOnE '2C3; NEW ''QRH, OPF- Cr g> WEST 57-" STBSIZ^ NEW YORK, NYV YO^K iCO'9 TELEPHONE !2I2) 32-6100 TOKYO OFFICE TQRANOMON OHTORI SU'-OiNO 4-3, TQRANOMON 1-ChOME MINATO-KU, TOKYO 'OS TELEPHONE 103} 507-0730 OUR FILE NO :emcra:i: ~o .ORIDE PROGRAM PANEL Re: CSHA "Z-Table11 Rule for VDC ^h 0 a ^ 1 has ashed that we review the final ZTable regulation p rcvidi.ag exposure limits for vinylidene cr*-onci3 rcr ccssz. ble legal issues. We have reviewed it and discussed it with Tr. Romano. Specifically, we have looked into the question of whether the Panel has any reasonable objection to the f inal rule on the basis of an argument that the proposal gave insufficient notice that OSHA was considerira a rs^c. ced exposure limit. Our conclusion is that the final rul a probably was not sufficiently different from the proposed rule to warrant challenge on a theory of insufficient nctic e under tne Administrative Procedure Act. This memorandum summarizes the law with respect to that issue and reaches the conclusion that litigation would orobabiv not be fruitful. We have not addressed the question of whether CSHA's conclusions about the adequacy of the proposed 5 ppm TWA or the need to adopt a 1 ppm TWA are supported by the record. OSHA's rationale for adopting the final standard -- that studies shew damage at 2d ppm and that VDC is a potential carcinogen -- does not seem to be so flawed as to ;ustify an argument that the standard is not supported by Ir. its proposed 'I-Table" rule, the Occupational hires'/ ana >.ea_t:i Atm_ristrat ion '"OSHA") or ("the Agency") suggests:; setting pirr_ssi,:,,e exposure limits ("PELS") for SL 064978 Paul, Hastings, Janofsky & Walker March 7, 1989 Page 2 vinylidene chloride ("VDC") at an 8-hour time weighted average (''TWA") of 5 parts per million ("ppm") and a 15minute short-term exposure limit ("STEL") of 20 ppm. 53 Fed. Reg. 21106 (June 7, 1988). The Agency stated that it was concluding preliminarily that these limits would protect workers from the "risk of liver and kidney damage and carcinogenity potentially associated with exposure to VDC at the levels permitted by the absence of any OSHA limit." Id. The Agency noted, however, that this standard might be an interim limit and that OSHA would promulgate a new limit "if it determined that such a new limit would substantially reduce significant risk." Id. OSHA indicated that the proposed rule adopted the same standard as the one advanced by the American Conference of Governmental Industrial Hygienists -- Threshold Limit Values ("ACGIH-TLV"). The proposal also noted that the National Institute on Occupational Health and Safety ("NIOSH") proposed that "employee exposure to VDC be reduced to the lowest feasible level," and stated that NIOSH considered VDC to be a carcinogen. Although there does not appear to be a specific statement in the proposal defining what NIOSH meant by "the lowest feasible level," the final rule indicates that this NIOSH recommended exposure limit ("REL") was 1 ppm -- the same level as the one finally adopted by OSHA. 54 Fed. Reg. 2567 (January 19, 1989). The proposed OSHA rule also outlined various studies and the conclusions drawn therefrom on the toxicity and carcinogenicity of VDC. B. Final Rule After reviewing the studies cited and several comments (most notably, those submitted by CMA and the Worker's Institute for Safety and Health ("WISH")), the Agency concluded than "these studies clearly demonstrate chat VDC can cause adverse liver and kidney damage at airborne concentrations as low as 25 to 50 ppm and suggest chat VDC is a potential occupational carcinogen." id. Thus, on January 19, 1989, OSHA adopted a final rule setting the allowable limit for exposure to 1 ppm as an 8 hour TWA. SL 064979 Paul, Hastings, Jaxofsky & Walker March 7, 1989 Page 3 C. Notice of Rulemaking The Administrative Procedure Act, 5 U.S.C, 551 et sea., requires agencies to give public notice of a proposed rule and to give interested parties the "opportunity to participate in rule making through submission of written data, views, or arguments, with or without opportunity for oral presentation." Id. at 553(b). This provision does not require a proposal to specify every aspect of the rule which may ultimately be adopted in final form. It does, nonetheless, require a sufficient description of the subjects and issues involved so as to allow interested parties a meaningful opportunity to comment. Trans-Pacific Conference of Japan/Korea v. Federal Maritime Comm'n, 650 F.2d 1235 (D.C. Cir. 1980), cert, denied. 101 S. Ct. 2315 (1980). If notice of the proposed rule is too broad or the final agency rule deviates too sharply from the proposal, the affected parties will be deemed to have been deprived of notice and of an opportunity to comment. Small Refiner Lead Phase-down Task Force v. EPA. 705 F.2d 506, 547 (D.C. Cir. 1983); Chocolate Manufacturers Ass'n of the U.S. v. Block. 755 F.2d 1098 (4th Cir. 1985. This does not`mean, however, that when an agency adopts a final rule which contains substantial changes from the proposed rule the new rule is automatically invalid and the agency needs to open a new comment period. International Harvester Co. v. Ruckleshaus. 478 F.2d 615, 632 n.51 (D.C. Cir. 1973). Nevertheless, to be valid, the change must represent a "logical outgrowth" of the prior notice and comments. South Terminal. 504 F.2d at 659. In determining whether a final regulation is a "logical outgrowth" of a proposed rule, the court must "proceed to compare carefully the specific language of the proposal with that of the final rule in light of the evidence adduced at the hearings." United Steelworkers v. Marshall. 647 F.2d 1180, 1221 (D.C. Cir. 1980). This standard essentially means chat "given a new opportunity tc comment, ccmmenters would not have their first occasion to offer new and different criticisms which the agency might find convincing." BASF Wvandcts Corn, v. Costle. 598 F.2a SL 064980 Paul. Hastings, Janofsky & Walker March 7, 1989 Page 4 637, 642 (1st Cir. 1979), cert, denied, 444 U.S. 1096, 100 S. Ct. 1063 (1980). D. Case Lav In the following cases, the court found that adequate notice had been given: 1. American Iron and Steel Institute v. EPA. 568 F.2d 284 (3rd Cir. 1977). EPA proposed regulations establishing maximum permissible levels of pollutants which could be discharged by certain manufacturing operations within the iron and steel industry. The proposed regulations surveyed the available pollution control techniques -- the best practable control technology currently available ("BPCTCA") -- that could be used in meeting these limitations. The court held that interested parties were sufficiently apprised that there was an issue as to whether recycling of partially clarified effluent was the BPCTCA and, therefore, that the Agency might adopt more stringent treatment technologies than those embodied in the proposed rule. Thus, the final rule was a "logical outgrowth" of the proposal. 2. South Terminal Coro, v. EPA. 504 F.2d 646 (1st Cir. 1974). In order to reduce carbon monoxide emissions in the Boston area, EPA proposed (1) a ban on street parking in downtown; (2) prohibiting travel on certain routes one day a week through a $5 sticker system; and (3) limiting the supply of gasoline. The Agency also warned the public that other alternatives being considered, including a plan for fewer available parking spaces downtown. After extensive public comment, the sticker and gas supply options were dropped. The final rule adopted a plan which had not been previously recommended and that required a freeze on present and a review of future parking spaces. The court upheld the final rule stating that "[ajlthough the changes were substantial, they were in character with the original scheme and were additionally foreshadowed in proposals and comments advanced during the rulemaking. Parties had been SL 064981 Paul, Hastings. Janofsky & Walker March 7, 1989 Page 5 warned that strategies might be modified in light of their suggestions." Id. at 658. 3. Small Refiner Lead-Phase Down Task Force v. EPA. 705 F.2d 506 (D.C. Cir. 1983). EPA proposed setting lead content limits for small refineries ("SRs") at 2.5 grams per leaded gallon ("gplg") which was more lenient than the level proposed for large refineries ("HRs"). The final rule set a much stricter level of 1.1 gplg, which was based on past production levels, for both SRs and LRs. This final rule reflected an attempt to close certain loopholes created by the disparate treatment of SRs and LRs. The notice has raised this concern but had not specifically listed which loopholes EPA might attempt to close. Nevertheless, the court found that SRs were on adequate notice of the past production requirements because they were generally aware that EPA was seeking to seal unidentified loopholes that might affect them and they were in fact aware that the LRs had proposed considering past production requirements. Thus, the final rule flowed logically from the earlier proposal. In addition, the court noted that the SRs' attorney had attended the public hearings and was closely monitoring the docket and that the SRs had responded to other information to which they objected. In the following cases the Court found that there had not been adequate notice: 1. AFL-CIO v. Donovan. 757 F.2d 330 (D.C. Cir.; 1985) . Prior to the final regulation amending the Service Contract Act, the definition under that Act of "in the United States" covered situations where anv part of the contract was performed in the U.5. The two proposals amending the Act highlighted the sections to be*amended. Neither notice indicated that the definition of "in the United States" was to be changed to cover only those actions actually performed in the U.S. The court held that because the change appeared only in the final rule itself without indication of the pending change, the modification was not a "logical outgrowth" of the proposed rule. SL 064982 I I Paul, Hastings. Jaxofsky & Talker March 7, 1989 Page 6 2. Chocolate Manufacturers Ass'n ("CMA'M v. Block. 755 F.2d 1098 (4th Cir. 1985). Where the Food and Nutrition Services of the USDA proposed a rule that would limit the sugar content allowed in supplemental foods -- without indicating that chocolate flavored milk would be affected by the final regulation -- the court held that the agency had not given CMA adequate notice. The court noted that although the final rule was an outgrowth of the proposed regulation, it wasn't a logical one, as chocolate milk had always been a permissible supplemental food in the program and there had never been any hint that it would be removed therefrom. Thus, CMA could not have anticipated such a provision in the final rule and therefore had not been adequately alerted of the need for comment. Conclusion Insufficient notice does not appear to be a valid basis for objecting to OSHA's final rule on VDC exposure limits. In its proposal, OSHA implied that several alternatives were being considered, including NIOSH's REL. CMA knew that OSHA and NIOSH had jointly recommended a 1 ppm VDC exposure level in 1978 and that NIOSH proposed that VDC be designated an occupational carcinogen. In its comments, CMA responded directly to that allegation and attempted to establish the NIOSH's proposal was unsupported by scientific evidence. CMA also recommended that ACGIH-TLVs be adopted (5/20 ppm) rather than NIOSH RELs (1 ppm). Because NIOSH's low TLV recommendation was mentioned in the proposed rule, even if in passing, and CMA referred to it in its comments, the proposed rule would probably be held to give adequate notice, and the final rule would be held to be a "logical outgrowth" of the proposed standard. In addition, if a comment period were to be re opened, CMA would non be getting its first opportunity to offer new criticisms or suggestions that the agency might find convincing. CMA has already advocated that VDC is not a likely carcinogen and that ACGIH-TLVs be used as the basis for_updating the Z-Table limits. OSHA addressed these claims but concluded that a lower exposure limit was warranted. SL 064983 Paul, Hastings, Janofskt & Walker March 7, 1989 Page 7 Further, OSHA specifically stated in the proposal that it might promulgate a new limit in the final rule if doing so would substantially reduce a significant risk. This statement, coupled with OSHA's direct evaluation of CMA's comment and other studies in the final rule and its notice in the proposal that it was considering the 1 ppm limit, makes it difficult to argue that the final rule deviated too sharply from the proposed one, thereby depriving CMA of notice. On the basis of the above discussion, it would be difficult to argue that the VDC Panel did not have sufficient notice of OSHA's consideration given to reducing the exposure levels for VDC to a level below the proposal. Consequently, it is unlikely that CMA could argue that there was insufficient notice of the proposed change in exposure limits to VDC. // ' ' n-- ,4.; -c '"* R. Bruce Dickson Leslie A. Gonzalez RBD/mbl SL 064984 I 2566 Federal Register / Vol. 54. No- 12 / Thursday. January 19, 1989 / Rules and Regulations tungsten J1977h, as cited in ACGIH exposed continuously to VDC significant increase in tumors (Viola and 1986/Ex. 1-3, p- 614), NIOSH states that concentrations of 5,15. 25, or 47 ppm for Caputo 1977/Ex. 1-937). Other information on the effects of exposure to 90 days; only the animals exposed to 5 investigators exposed rats to 25 or 75 ^rfpolliuble tungsten compounds in the ppm showed no increases in mortality ppm by inhalation for six hours/day, rking population is not available. The (Prendergast, Jones, Jenkins, and Siegel five days/week for 18 months, or to 60, CGIH (1986,/Ex. 1-3, p. 614) 1967/Ex. 1-926). 100, or 200 ppm VDC in their drinking recommends a lower TLV for the Nasal irritation, liver cell water for two yearn, and found no soluble, as compared to the insoluble, degeneration, and retarded weight gain increase in tumor incidence in these compounds of tungsten because of the were reported in rats following 20 six- animals (Rampy, Quast. Humiston et a!. former'3 greater systemic toxicity. No hour exposures to 500 ppm VDC [Gage 1977, as cited in ACGIH 1986/Ex. 1-3, p. comments other than those of NIOSH 1970/Ex. 1-318); at 200 ppm, only nasal 628). In mice, VDC was not active either (Ex. 8-47) were received on this irritation occurred. Studies by Torkelson as a whole mouse skin carcinogen or by substance. and Rowe [1981b, as cited in ACGIH subcutaneous injection. In the final rule, OSHA is establishing 1986/Ex. 1-3, p. 628) in which rats, In other studies, VDC proved - an 8-hour TWA of 1 mg/m3 and a STEL rabbits, guinea pigs, and dogs were mutagenic in both E. coii and S. of 3 mg/m3 for tungsten and its soluble exposed to 25,50. or 100 ppm VDC for typhimurium strains (Greim. Bonse, compounds, measured as tungsten. The eight hours per day, five days per week Radwan et aL 1975/Ex. 1-904; Bartsch, Agency concludes that these limits will for six months revealed injury of the Malaveille, Montesano, and Tomatis protect workers againstIhe significant kidneys and liver in all animals at all 1975/Ex. 1-889). VDC has been risks of systemic toxicity, anorexia, levels of exposure. Maltoni (1977/Ex. 1- implicated as a tumor initiator m a colic, incoordination, trembling, and 985) andMaltoni, Cotti, Morisi, and carcinogenesis bioassay by Van Duuren, dyspnea, all of which constitute material health impairments that are associated with exposure to these compounds at levels above the new PELs. VINYUDENE CHLORIDE fl.lDICHLOROETHYLENE) CAS: 73-35-4: Chemical Formula: CHi= CCli H.S. No. 1428 Previously, OSHA's Z tables did not include a limit for vinylidene chloride (VDC). The ACGIH has established 5 , ppm as an 8-hour TWA and 20 ppm as a 15-minute STEL NIOSH and OSHA, in 1978. jointly recommended that iloyee exposure to VDC be reduced {e lowest feasible level on the basis TDCs carcinogenicity (NIOSH/ OSHA 1978/Ex. 1-1119). OSHA proposed a PEL of 5 ppm (8-hour TWA) and a STEL of 20 ppm. However, in response to record comments, the final rule promulgates a 1-ppm limit as an 8hour TWA. Vinylidene chloride is a f j colorless liquid that polymerizes readily.- Chieco (1977/Ex. 1-1090) conducted an evaluation of VCD's carcinogenicity in which mice, rats and hamsters were exposed to levels from 10 to 150 ppm for four hours per day, five days per week for 52 weeks, with results reported through week 98 of the study. In those mice exposed to 25 ppm VCD, 21 percent of the males and 1.5 percent of the females developed kidney adenocarcinomas; these tumors were not seen in rats exposed to amounts of VDC up to 150 ppm. Exposures of 100 or , 150`ppm in rats did produce a significant increase in mammary adenocarcinomas, and this response was dose-related (Maltoni 1977/Ex. 1-985; Maltoni, Cotti. . Morisi. and Chieco 1977/Ex. 1-1090). Overt toxicity and mortality occurred early in the studies after four-hour exposures at levels of 50 ppm in mice and 200 ppm in rats; hamsters exposed to 20 ppm VDC .showed no increase in. tumor incidence (Maltoni 1977/Ex. 1985; Maltoni, Cotti Morisi, and Chieco Goldschmidt, Loewengart et al. (1979/ Ex. 1-936). Studies by Reitz, Watanabe. McKenna et aL (1980/Ex, 1-927) suggest that VCD's tumorigenicity is a result of its ability to initiate ceil injury, rather than of its ability to alter the genetic material of an injured cell. However, VDC has been shown to alkylate DNA in situ and increase the rate of DNA repair to a small extent in mice (Norris and Reitz 19&4/Ex. 134B). The actual cell injury is caused by VDC metabolites, which are highly reactive and cytotoxic (Maltoni 1977/Ex. 1-985; Hathwayl977/ Ex. 1-906; Henschler and Bonse 1977/Ex. 1-908). -` A cohort study of 138 VCD-exposed workers did not identify any VCD- related health effects in these workers (Ott, Fishbeck. Townsend, and .. . Schneider 1976/Ex. 1-924). The cohort was too small to provide any evidence that VDC is not likely to be _... carcinogenic. - ' /, _ The acute oral LDy> for male rats is 1977/Ex. 1-1090), _,, ! - , The Chemical Manufacturers 2500 mg/kg (Jenkins, Trabulus, and A study by. Murray, Nitschke, Rampy, Association submitted the results of an v Murphy 1972/Ex. 1-960). The LC** for ' C and Schwetz (1979/Ex. 1-920) 1 NTP gavage study of VDC in mice and rats exposed to a single four-hour .V Cc investigated the embryotoxic, fetotoxic, " rats (NTP 1982/Ex. 134B). The only exposure ofVDC vapor was reported as ' and teratogenic effects of inhaled and ; observed significant increase in tumor 6350 ppm in one-study (Siegel, Jones. ingested VDC [in rat3] and inhaled VDC. .. incidence occurred in low-dhseiemale Coon, and Lyon 197l/Ex. 1-371) and;., (in rabbits). In the inhalation studies, Z mice; this increase was hot considered 32,000 ppm in an earlier study r ' rats were exposed to 2ft 80, or 160 ppm to be related to"VDC administration. (Carpenter. Smyth, and Pozzani 1949/Ex," VDC for seven hours per day. VDC was . because similar effects were not ..... 1-722). liquid VDC causes transientT;V toxic to both the adults and their observed in high-dose female mice, male irritation-to the eyes of rats but has little ' embryos at levels of 80 and 160 ppm mice, or rats. The NTP.(1982/Ex. 134B) effect on exposed skin if the VDC is ` ' among the rats, and at 150 ppm in concluded that VDC was not . . illowed to evaporate (Torkelson and rabbits. At exposure levels of 20 ppm in carcinogenic in mice or rats exposed by Rowe 1981b, as cited in ACGIH 1986/Ex. rats and 80 ppm in rabbits, neither gavage, but cautioned that a maximum 1-3. p. S23). - , ' - maternal toxicity nor effects on tolerateddose had not been Prer.deTgast and co-workers (1967/Ex. embryonic or fetal development were ' demonstrated and that previously t-926) exposed rats, rabbits, guinea pigs, noteci In the ingestion study with rats, . reported studies had shown that. and monkeys eight hours/day, five, drinking water containing 200 ppm VDC Z carcinogenicity is associated with VDC days/week for six weeks to 395 mg/m3 caused no toxic effects in either the rats inhalation by animals.-. . , - (100 ppm]r these authors saw no visible -or their offspring. . Based on the carcinogenicity evidence ugr.3 of toxicity.while the exposure was -Two strains of rats exposed to 75 or described above, NIOSH (Ex. 8-47, m process, but rabbits and monkeys lost' lOOppm VDC for Eve days/week, six ' Table N6B) indicated that VDC i3 a waiaht. These same species were ' '' hours/day for 12 months did not show a suitable candidate for an individual 6(b) ilmak: gi of demc ponse pence lecies--' DC is . jsk to h 0 00 iOSH iteiiigc SHA 1 I*np*saiudsep- lyl oh . iteme Jxicity fMatth (the V fealth propose for VDC protect. 116]. TIpender 15 ppm icreas yueTor {mACC Sound I: .ese c ..cci: provide {febstar. ihould >pm as isk ass it" (E: f OSH. kuvidenc 1SH. ITOpOSt iht affV __otn sv Kuestio- M1967/E fobserve evels v U3topa gexpvse' elated i exp.' Kccupa fday, fh fcRowe 1 iEx. l- cliver i after {25 ppn smontr OS': sclear; radver k'airbc* f 50 ppZpolkr U rlL Auk Nj SL 064985 Federal Register / Vo'.. 34. Na. ii'ursdav. lru VA 1989 A Ik, . \3 (vioIa and rer 0 25 or 75 uriZday, lo 60. Kins nd no n these Piston et al /ex- i-3, p; -9ve ei;be,. Jgen or by r in a in Duuren, !. (1979/ .'atanabe, 7) suggest result of , rather enetic vever, iteDNA DNA : (Norris ictual cell oLites, ytotoxic /ay 1977/ :d- orkers cohort 'deace is of an re and dy tumor `emale idered ion /e, male I34B) red by .mum kb) faking. However, the CMA (Ex. 165) within the meaning of the Act. g5 of the opposite opinion, stating that ^'demonstrated lack of tumor ponse in most studies, coupled with ^dence that VDC metabolism is jies-specific."demonstrates that f)C is unlikely to pose an oncogenic jc to humans" (Ex. 165, p. 42), CMA Jo objected to the statement by JOSH and OSHA in the joint Current Therefore. OSHA concludes that the proposed limits of 5 ppm as an 8-hour TWA and 20 ppm as a STEL will not sufficiently protect workers from the significant risk of organ damage, and , that a further reduction in the PEL is warranted. Accordingly, OSHA is establishing a 1-ppm 8-hour TWA limit for vinylidene chloride in the final rule. Jfteiiigence Bulletin on VDC (NIOSH/ WELD IMG FUMES , 1978/Ex, 1-1119) that VDC be CAS: None; Chemical Formula: Not available Kisidered a potential carcinogen H.S. No. 1430 fcause of its structural similarity to Syl chloride; the CMA considered this Stement inappropriate, given the lacity data available. latthew Gillen and Scott Schneider ftBe Workers Institute for Safety and ealth (WISH) commented that the proposed 5-ppm PEL and 20-ppm STEL or VDC would not provide sufficient protection from systemic effects (Ex. l|6). They pointed out that the study by endergast et al, (1967/Ex. 1-926) found JS'ppm to be the lowest effect level for Eficreased mortality in animals, and that he Torkeison and Rowe (1981b, as cited r [ACGIH 1986/Ex. 1-3, p. 628) study jjTduhd liver and kidney injury in animals. (These commenters stated that the ^kCGIH TLV cannot be considered to provide adequate protection for this rsubstance. Given this Fact, OSHA hould consider the NIOSH EEL of 1 - ppm as an interim value until further OSHA formerly had no limit for exposure to welding fumes, which are defined as fumes that are generated by the manual metal arc or oxy-acetylene welding of iron, mild steel, or aluminum. The ACGIH has set an 8-hour TWA of 5 mg/'m3for these welding fumes, measured as total particulate in the weider`3 breathing zone. OSHA proposed an 8-hour TWA of 5 mg/m3 for these fumes; this limit is established in the final rule. This limit applies to the total fume concentration generated during the welding of iron, mild steel, or aluminum; the fumes generated by the welding of stainless steel, cadmium, or lead-coated steel, or other metals such as copper, nickel or chrome are . . considerably more toxic and should be kept at or below the levels required by their respective PELs, Welding fumes consist of metallic oxides generated by the heating of metal being welded, the ` risk assessment studies can be carried welding rod. or its coatings. [&uf (Ex. 116). Although these types of welding _OSHA has re-examined the health generally produce fumes consisting of [evidence in light of the comment by aluminum, iron, or zinc oxides, other [WISH, and has determined that the toxic gases may also be produced in (proposed 5-ppm TWA PEL for VDC does large amounts (Ferry and Ginther 1952/ [hot afford workers sufficient protection Et 1-900; Ferry 1954/Ex. 1-782; [from systemic effects. Although it is Silverman 1956/Ex. 1-1169; Homer and [questionable, in the Prendergast et al. Mohr 1957/Ex. 1-787). The welding of [(1967/Ex. 1-926) study, that the iron metals may give off fumes of [observed deaths at lower exposure manganese, silicate, and various organic levels were compound-related, binders. Aluminum welding may . histopathologic examination of animals . generate fumes consisting of fluorine, ,.,- exposed to 47 ppm showed treatment- >' arsenic, copper, silicon, and beryllium ^ related liver and kidney damage. Usings: (NIOSH 1975h and American Welding, : an exposure regimen similar to - m, .o Society 1974, both as cited in ACGIH ... . occupational exposure (i.e;, eight hours/'. 1986/Ex. 1-3, p. 634). Eighteen different jday, five days/week), Torkeison and r substances, including fluoride. 7 - f.Rowe (1981b, as cited in ACGIH1986/ manganese, silicon, titanium, and ! Ex. 1-3, p. 628) demonstrated kidney and sodium and potassium silicates, have E? liver toxicity to four species of animals been measured in the fumes resulting * after exposure to VDC levels as low as from the weiding of mild steel (ACGIH - 25 ppm were administered for only six 1986/Ex. 1-3, p. 634). months. Excessive exposure to welding fume OSHA believes that these studies can cause a variety of disorders, most ' clearly demonstrate that VDC can cause notably metal fume fever. It has been adverse liver and kidney damage at estimated that 30 to 40 percent of all airborne concentrations as low as 25 to weiders have experienced metal fume , 50 ppm and suggest that VDC is a fever at some time (Abraham 1983, in potential occupational carcinogen. Liver Environmental and Occupational and kidney damage and cancer dearly Medicine. W.N. Rom. ed.. p. 146). This , constitute material health impairments disorder, which results from exposure to freshly formed metal fume, results in the appearance of delayed, flu-like symptoms, including dyspnea, coughing, pains in muscles and joints, fever, and chills. Recovery usually requires one or two days of time away from work. In addition to fume fever, exposure to welding fume may damage the small airways, causing interstitial pneumonia (Abraham 1983). Several commenters. the American Iron and Steel Institute (Exs. 129, 1831, the Abbott Laborator.es (Tr, 9-155 to 9156), and the American Welding Society (Ex. 3-860), were of the opinion that OSHA's discussion of welding fumes in the NPRM was not clear with regard to whether the limit applied to exposure samples taken inside or outside of the welding helmet. OSHA wishes to clanfy that welding fume is to be measured in the breathing zone of the welder; the specific details of the appropriate positioning of the sampler should be determined on the basis of guidance in the Field Operations Manual (OSHA 1984). This is consistent with a past OSH Review Commission decision (8 OSHRC1049). NIOSH (Ex. 8-47) stated at the hearing that welding fumes should be designated as a carcinogen. This view was also endorsed by Dr.- James Melium of the New York State Department of Health (Tr. p. 11-104). In response to these commenters, OSHA notes that there are few data- sufficient to establish a-dose-response for the fumes. Accordingly, OSHA believes it would b-. premature to identify these fumes as potential occupational carcinogens. OSHA concludes that a PEL for welding fumes is needed to protect workers involved in the welding of aluminum, iron, or mild steel from the significant risk of metal fume fever and respiratory irritation associated with tfc generation of welding fumes. In the fina rule. OSHA is establishing a TWA of 5 mg/m3 for these particular types of welding fumes, measured as total ~ particulate inside the welder's breathin zone. The Agency find* that this limit will substantially reduce the significan risk of material health impairment to which manual metal arc or oxy- , acetylene welders of iron, mild steel, c aluminum were previously exposed in the absence of any OSHA limit. ZINC OXIDE (FUME1 CAS: 1314-13-2: Chemical Formula: ZnO H.S. No. 1437 OSHA's former exposure limit for z oxide fume was 5 mg/.m3 as an 8-hour TWA. The ACGIH recommends a 3-c m3TWA and also has a STEL of 10 rr m3. NIOSH recommends a 5-mg/m31 SL 064986 - -i &f!Z caais ;or proposing a new nrmt. ;or adenocarcinomas; these mmers were (Ott. Fallback. Townsend, und tungsten and compounds (soluble). At not seen in rats exposed to amounts of Schneider 1976). the time of the final rule, OSHA will VCD up to 150 ppm. Exposures of 100 or OSHA is proposing an 3-hour TV/A of promulgate a new limit if the Agency 150 ppm in rats did produce a significant 5 ppm and a 15-minute STEL of 20 ppm determines that this limit will increase in mammary adenocarcinomas, for vinylidene chloride. The Agency substantially reduce significant risk. and this response was dose-related preliminarily concludes that these limits VINYLIDENE CHLORIDE [1.1- (Maltoni 1977; Maltoni, Cotti, Morisi, will protect workers from the risk of ----- Dll'HLORUETHYLENE) CAS: 75-35-4: Chemical Formula: CHj = CCIi and Chieco 1977). Overt toxicity and mortality occurred early in the studies kidney and liver damage and carcinogenicity potentially associated H.S. No. 1428 after 4-hour exposures at levels of 50 with exposure to VCD at the levels Currently. OSHA's Z tables do not have a limit for vinylidene chloride (VCD). The ACGIH has established S ppm as an 8-hour TWA and 20 ppm as a ppm in mice and 200 ppm in rats: hamsters exposed to 20 ppm VCD showed no increase in tumor incidence (Maltoni 1977; Maltoni, Cotti, Morisi, permitted by the absence of any OSHA limit. This limit may be an Interim limit; as future priorities permit, the Agency may perform a quantitative nk 15-minute STEL. NIOSH recommends and Chieco 1977). assessment for VCD and consider that employee exposure to VCD be A study by Murray, Nitschke, Rampy, further rulemaking. This health evidence i 5 reduced to the lowest feasible level and- and Schwetz (1979) investigated the considers VCD a carcinogen. Vinylidene embryotoxfc, fetotoxic, and teratogenic forms a reasonable basis for proposing a new limit for vinylidene chloride (1,1- chloride is a colorless liquid that effects of inhaled and ingested VCD (in dichloroethylene). At the time of the .1 polymerizes readily. rats) and inhaled VCD (in rabbits), in final rule. OSHA will promulgate a new >< The acute oral LD*> For male rats is 4 2500 mg/kg (Jenkins. Trabulus, and the inhalation studies, rats were limit if the Agency determines that this exposed to 20, 80, or 160 ppm VCD for 7 . limit will substantially reduce Murphy 1972). The LCk> for rats exposed hours per day. VCD was toxic to both significant risk._______ to a single 4-hour exposure of VCD vapor wa3 reported as 6350 ppm in one study (Siegel. Jones, Coon, and Lyon 1971) and 32,000 ppm in an earlier study (Carpenter, Smyth, and Pozzani 1949). Liquid VCD causes transient irritation to the eyes of rats but has little effect on exposed skin if the VCD is allowed to-, evaporate (Torkelson and Rowe 1981). Prendergast and co-workers exposed rats, rabbits, guinea pigs, and monkeys 8 hours/day, 5 days/week for 8 weeks to 395 mg/m3 (100 ppm); these authors saw- the adults and their embryos at levels of 80 and 160 ppm among the rats, and 160 ppm in rabbits. At exposure levels of 20 ppm in rats and 80 ppm in rabbits, neither maternal toxicity nor effects on embryonic or fetal development were noted. In the ingestioiTstudy with rats, drinking water containing 200 ppm VCD caused no toxic effects in either the rats or their offspring; Two strains of rats exposed to 75 or 100 ppm VCD for 5 days/week, 6 hours/ day for 12 months did not show a ^wKldlng FUMES CAS: None; Chemical Fommla.-Not available H.S. No. 1430 . - OSHA currently has no limits for exposure to welding fumes, which it defines as fumes that are generated by the manual metal arc-or oxy-acetylene welding of iron, mild steel, or aluminum. The ACGIH has set an 8-hour TWA of 5 mg/m3 for welding fumes, measured as total particulate inside the welding helmet. no visible signs of toxicity while the significant increase in tumors (Viola and Although welding of these types exposure was in process, but rabbits Caputo 1977). Other investigators generally produces fumes made up of and monkeys lost weight,1 These same exposed rats to 25 or 75 ppm by aluminum, iron, or zinc oxides, other species were exposed continuously to inhalation for 6 houra/day. 5 days/week toxic gases may be produced in large VCD concentrations of 5,15, 25, or 47 for 18 months or to 60,100, or 200 ppm amounts (Ferry and Gintber 1952; Ferry ppm for 90 days; only the animals VCD in their drinking water for 2 years 1954; Silverman 1956; Homer et al. 1957). exposed to 5 ppm showed no increases and found no increase in tumor Iron metals may give off fumes of in mortality (Prendergast, Jones, Jenkins, incidence in these animals (Rampy, manganese, silicate, and various organic and Siegel 1967). v Qua3t, Humiston et al. 1977). In mice, binders. Aluminum welding may result Nasal irritation, liver cell VCD was not active either as a whole in fumes consisting of fluorine, arsenic, degeneration, and retarded weight gain mouse akin, carcinogen or by copper, silicon, and beryllium (NIOSH were reported in rats following twenty subcutaneous injection. n.d.: American Welding Society 1973). 9-hour.exposures to 500 ppm VCD (Gage In other studies, VCD proved Eighteen different substances, including 1970); at 200 ppm, only nasal irritation : mutagenic in both E. coli and S. fluoride, manganese, silicon, titanium, occurred. Studies by Torkelson and typhimurium strains (Greim. Bonse,, . ' and sodium and potassium silicates, Rowe (1981) in which rats, rabbits, Radwan et al. 1975; Bartscn, Malaveille^ have been measured in the fumes guinea pigs, and dogs were exposed to Montesano, and Tomatis 1975). VCD has: resulting from the welding of mild steel 25,50, orlOO ppm VCD for 8 hours per ; been implicated as a tumor initiator in a (ACGIH 1986, p. 634). The process of day, 5 days per week for 6 months carcinogenesis bioassay by Van Duuren shielded arc welding is known to revealed injury of the kidneys and liver (1979). Studies by Reitz, Watanabe, . produce ozone, arid when carbon in all animals at all levels of exposure. ' fMcKeuna et al. (1980) suggest that . , ` dioxide is used'as a'shield gas, carbon Maltoni (1977) and Maltoni, Cotti, ( f VCD's tiimorigenicity is a result of its . monoxide fs giveri'off (NIOSH n.d.: Morisi, and Chieco (1977J conducted an J ability to initiate cell injury and not of"- " American Welding Society 1973), evaluation of VCD's carcinogenicity in its ability to alter the genetic material of The adverse health effects associated which mice, rats and hamsters were (. an injured cell. The actual cell injury is 1 with over exposure to welding fumes are exposed to levels from 10 ppm to 150 caused by VCD metabolites which are those of metal fume fever--chills and ppm for 4 hours per day, 3 days per highly reactive and cytotoxic (Maltoni fever, profuse sweating, and week for 52 weeks, with results reported 1977: Hathaway 1977; Henschler and -weakness--snd respiratory irritation. through week 98 of the study. In those Bonse 1977), ' if mice exposed to 25 ppm VCD, 21 percent A cohort study of 138 VCD-exposed i of the males and 1.5 percent of the - d females developed kidney workers did not identify any VDCrelated health effects in these workere OSHA preliminarily concludes chat a PEL for welding fumes is needed to protect workers involved in the welding of aluminum, iron, or mild steel from the $ '4 XttLc SL 064987