Document aDEEjO7jqEvvrp4xjDwydzkJX

Acute Inhalation Toxicity of Vinyl Chloride to Laboratory Animals E. MASTROMATTEO, M.D., A. M. FISHER, Ph.D., H. CHRISTIE, B.Sc., and H. DANZIGER, M.D. Division of Industrial Hygiene, Ontario Department of Health, Toronto, Ontario; Department of Physiological Hygiene, School of Hygiene, University of Toronto, Toronto, Ontario; and Welland County General Hospital, Welland, Ontario Introduction scribed as very slight. Elimination from the '< was very rapid. These authors quoted the a FIRST prepared in 1833, vinyl chloride has of Schaumann( with experimental animals M come into increased use in the last decade in rats and dogs were able to endure repeater: the production of polyvinyl chloride resins. Thecosis without any pathological evidence ni \ fire and explosion hazard of the monomer and its or kidney damage. According to .'Ylwirtg- narcotic properties on acute exposure are well concentrations of seven to ten per cent 1 known. As an industrial material, however, it has would he narcotic to humans in a short tin.' been regarded as of moderate toxicity. A Thresh 12 per cent would lie dangerous. old l.imit Value of '>()() ppm was established by Vinyl chloride has been studied as a p -- ' the American Conference of Governmental In anesthetic agent. (Aster and associates" noted f dustrial Hygienists. incoordinated muscular activity of the ext;-- .Vo industrial fatalities associated with its use ties and cardiac arrythmias of a serious Mat-: have previously been reported. It was therefore were observed in all six dogs list'd in their exp r of sperhd intercat when two fatalities oeeurred in incut.. Carr and others7 found that vinyl rh!"r a plant liamlling vinyl eldoride. This plant is eu- produced .sensitizat ion of the nivm ardiii'a aau' .l in the polymerization of the gaseous mono three of seven dogs in which it wiv nhiunet' r mer a itli (lie aid of catalysts. One worker died wlnle cleanimi out a polymerization vessel and the as an anesthetic, agent. Two cases of vinyl chloride gassing nmirii otlna while working in a pit. Ortnils of these two a factory in < Ireat, Ihitaiii where polyx inv! < h fatalities have. Iieen reported by one of the au thors.1 ide resin was being made. These were re|i"i! the Chief Inspector nl ["'actories " In one 1 Published information on the acute toxicity of process worker was standing outside a public vinyl chloride to experimental animals proved zation vessel and washing it with a water .scanty. Patty, Yant and Waite2 in 1930 reported After ten minutes of this he suddenly culls: - on the acute response of guinea l>igs to vinyl across the open manhole. Artificial rcsiisc'e' chloride. They found that exposure to 30 to 40 was successfully applied. Subsequent syaip' per cent in air killed guinea pigs in a short time; ex]ierienced by this worker were tightness exposure to ten per cent was endured lor several chest, nausea, abdominal pain and headache, hours. Congestion and edema of the lungs with second case occurred in a maintenance > hyperemia of the liver and kidneys were noted. wlin was overcome while repairing a xmyi m > Peoples and I wake-1 found the minimal anes thetic rang''of vinyl chloride in mire exposed lor leak. 1 hit.11 men were hospitalized. Another V'-1 whose hands were urridentully spray cu ten minutes was S to 12 per cent ill air; 2d to 30 vinyl chloride liquid under pressure dr'cCp per ci nt was fatal in ton minutes. Mog~- and rab lmru. This latter case was reporteil In 3 bits urn- anesthetized within one minute when exposed to a roiieculrutioii ill ;ilMint lx per cent Such burns may occur wit It other highly \ in air. llrcmiiT was very rapid with no apparent materials when sprayed unto the hand- a> a untoward rlh-ot even alter prolonged anc.-t licsta. under pressure. I.ohiunnn and I'lury1 noted that wnvl chloride h'ilatn\':i and (li'iuislK,rglu in I`ho rcnic w;e highly nan otic but bail a wale margin lie- loginur conditions ill u polyvinx'l u'-"' t us im its narcotic and Ictlial nun cut rut ii ms. Its plant, in (lie I'.S.S.R. The plant :c mg::-' local uritating elTrrl, .and its toxicity were de the polymerization nl vinyl chloride by [ ad it : cat .cntr I mm Tlitv mun ::h.n Expi in 24442001 i BFG31172 luslrial II i/ijiaic Journal 'Mir, ,.il:ilys|.. Air sampling was dom* :111< 1 (lie conul i a I nin itf vinyl rhlnridr was lomiil (<> \ ary >111 about. 20 |>|>ni (n :il>oii(. 21") ppm. (U.S.S.ll. hivdiolil Limit A':111i<: I nig/litcr nr about 100 nil. A spastic typo lilond vessel ilisonler was rilmil in workers from this pliml.. IVesiise of tin- recent labilities mentioned avr it was il(vid(`(l to innleitako acute inliala,ii sliiilirs in lalmralory animals with commer,llv available vinyl chloride. This was dnno I Kith r comparison with I'arlior wnrk anil to provide formation on the acute response and patholngi I ('lis nges in more t han one species of lalKiratory awal. fiperimental Materials and Procedures Vini/l Chloride: The vinyl ehloride was supplied a metal cylinder tinder pressure. A commercial . i,lc with the following specifications was used: lie cnivity at 20C vr content \nc range C i-oern chloride content vlcnc i]<lchy(le n v per cent) : (Tdifs (per cent) o.9&.vn.m None -11 to -9.5 None 10 ppm maximum 20 ppm maximum Essentially iron free 99.5 maximum 0.5 maximum Pare vinyl ehloride is a colorless gas at room ..;ierstiirc; its boiling point is -- 13.f)C. It has . ,v< tish odor. Its flash point is given at -- 78C Us explosive limits in air from A to 22 per I; lias flic molecular formula ('IImCIICI. . inifil.c Alice, rats and guinea pigs were used > study. Test and control animals were taken a the same lalxiratory stock. All were fed a dard commercial diet and housed in the same . All were of the same stage of development. . iiipmait: The inhalation chamber capacity .Vcfi liters. It was equipped with a viewing j,w and an inlet tube. Vinyl ehloride was re >1 in gaseous form through an adjustable on the top of the containing cylinder, then sub connecting rubber tubing and a recall ed Fisher flow-meter. Fresh air was pumped Motor at an adjustable controlled rate through ..ter. The streams of air and vinyl chloride - combined at appropriate rates of flow by a - Y-tube leading through further rubber tub. m the animal chamber inlet, to deliver a Mining stream in the desired proportions, nations and adjustments were made to pro- thc following flow concentrations of vinyl ride in air for delivery: 10, 20, 30 and 40 per All concentrations are expressed in this ret as per cent by volume in air. No determina tions of vinyl ehloride rouceiifrations were done in the lest, chamber during the experiments. P.r/iiriinnilal Priiniliircs: PilTerent groups of live mice, five rats ami five guinea pigs were, placed in the chamber and exposed for thirty minutes to concentrations of 10, 20 and 30 per rent vinyl ehloride in air. Similar groups of con trol animals were maintained lint not. exposed to vinyl chloride. At the end of thirty minutes ex posure the test animals were immediately re moved to fresh air. An additional group of five guinea, pigs was exposed to a concentratioii of 40 per ecu I, vinyl ehloride in air. Ill all tio expeiimen- tal animals were involved. Observations were re corded on the animals during and after exposure. 'I'lte. animals which died either during the ex posure or after a delay period were ailtopsied soon alter death. Two weeks after the. exposure, sur viving test animals and controls were sacrificed by a blow to the head with the exception of four control rats which were killed by exsanguination. All animals were examined for gross pathologi cal changes. Tissues were removed from all ani mals for microscopic examination. The lungs, liver, kidney and heart were removed in all cases. The brain, adrenal, spleen, trachea, lymph nodes, and the eye were removed from represen tative animals in each group for study. The tissues were preserved in formalin and sections made for shrining with hcmatoxylin-cosin. Special stains were made where indicated. Observations Control Animals: No symptoms were exhibited by the 15 control animals and no deaths occurred. Ten Per Cent Vinyl Chloride: The response of animals exposed to this concentration is recorded below in summary form: Exposure Time (minutes) 1 5 10 15 20 25 30 Response Slight irritation in mice and rats. Increased motor activity first in mice, then rats and guinea pigs. Increased motor activity in all species; twitching of extremities in mice. Pronounced tremor, unsteady gait and muscular incoordination in all species. Mice and rats in side [Motion; muscular incoordination, tremors and twitching of extremities in guinea pigs. Mice and rats unconscious, guinea pigs very unsteady but still standing. Mice and rats in deep narcosis; guinea pigs in side position with tremors--one unconscious. Exposure was stopped and the animals removed to fresh air. All recovered within five minutes. Twenty Per Cent Vinyl Chloride: The response i I I i Z O Q Z V ttZ BFG3U73 396 October, /; holur of animals exposed to this concentration is re corded below in summary form: Exposure Time 'minutes) 1 10 15 20 25 30 Response Immcdiute irritation in mice and rats. Muscular incoordination in mice and rats. Mice and rats on their .sides with marked tremors and twitching of the extremi ties; unsteadiness and muscular inco ordination in guinea pigs. Mice and rats unconscious with rapid irregular breathing; guinea pigs un conscious but showing marked twitch ing. All animals in deep narcosis; respirations irregular and rapid. Deep narcosis; breathing slow and shal low. Urcuthing ceased in one mouse; frothing at mouth and nostrils in mice and rats. All animals in deep narcosis. Exposure was stopped and the animals removed to fresh air. Mice and rats recovered faster than the guinea pigs and appeared normal within five minutes except for one mouse which was dead. The guinea pigs continued to show muscular in coordination, unsteadiness on their feet until 20 minutes after removal from exposure. Thirty Per Cent Vinyl Chloride: The response of animals exposed to this concentration is recorded below in summary form: Exposure Time (minutes < Kcsjtonse Mici* showed irritation immediately and the rat* .showed irritation quickly thereafter. Muaculnr incoordination in mice and rut*. Mice and rats in aide position with marked tremor* and twitching of the extremities; muscular incoordination in guinea pig* with developing paraly sis of tin? extremities. All animals unconscious; rapid irregular respiration* in mice and rats with frothing ulx>ut nose ami mouth; twitching of extremities still occurred occasionally in guinea pigs. Respiration* stopped in mice; breathing slow and shallow in rats; guinea pig* still exhibited oreasintial twitching movements ol tin* extremities. Mreathing slopped in mi*: respirations slow mid shallow in guinea pig*; twitching <f extremities still present in guinea pigs. Mice nod I'm l.i ilill; guinea jigs in deep Maicosi* with slow shallow breathing Kxposun; was stopped ami ( hr aninials removed to fresh air. Tin* nuee ami rats unv dead. The guinea pitps tixik '1~> miimles to iviurn to their normal appe.-mmer ami arlivitv. (hie guinea pig from this group died within -I hours following exposure. ITable Number of Deaths in Different Groups of I n Mice, Rats and Guinea Pigs Exposed forTliirc. Minutes to Varying Concentrations of Vine Chloride in Air Vinyl chloride concentration f|>cr cent by volume in air) Laboratory animal Mice Rats b (luintNi pies T1 10 20 30 *10 Total 0/5 1/5 5/5 -- 6/15 0/5 0/5 5/5 -- 5/15 i;, 5 0/5 1/5* 2/5* 3/20 : I1 l. n, H' * A delayed death occurred within 24 hours follow in:; -ws `" Forty Per Cent Vinyl Chloride: Only five vtuiio pigs were exposed to this concentration. Sign*": irritation were immediately apparent. Mii.iiibr incoordination appeared within seconds.- Alt' five minutes all the guinea pigs were unconscic :with slow shallow breathing. At the end "f tbexposure period one guinea pig was dead and tbremaining four were in deep narcosis. These sur vivors took dll minutes to return to their noniin. appearance and activity, bat one died within tb following 21 hours. The number of deaths occurring in difleMit groups of five laboratory animals exposed nr thirty minutes to varying concentrations "1 viny, chloride In air is shown ill Table I. Pathological Findings Gross pathological and histological studies were carried out. The findings are summarized 1 wlou. Control Animalx: These animals showed r," gross or microscopic evidence of damage. Ten Per Cent Vinyl Chloride: All test auini:dsurvived this exposure. They were sacrificed I'"1 weeks later. On gross examination there was mideuce in mice of slight hyperemia of the hum*. Tliis was less marked in rats. Guinea pigs shew.-! no difference from control animals. On liisfelegiexamination the mice showed very slight engorge* incut of Uic pulmonary vessels. One aieu-'showed degenerative changes ill Ihc Iuhnlar epi thelium of flic kidney with hydropic swelling The rats showed slight cnngcsl ion of Ihc capillar ies in the llllig. I .lings ill I he guinea pig were ac slightly more hyperemie Ilian those of Ihcroiiti" animals. Tiernty Per Cent Vinyl Chloride: One iiiuii-' died as ;t result, of .'ill miuilles exposure to thicmicciil ration. Ihilmomiry congestion \vas evident on gross examination. Microscopically, there i ;i<m m j M.ttVh Tin* li:i!i'J Th< '.'t'U'i f (*n-' hut it w\ t!i' m:tN- liver norm 77. ti<m 1' M **1 Si'llK iu i "lie i then Senv i : ri:t 1 wSS > pul n j I'lla'J Ml pi | lirM 1 "1 t' who -"t ' '1 ; two Ups In < t'-ri ; n:i\ . la T ;/ nui 'Ul! hui t!u tw 24442.003 BFG31174 ,slri<ii llijijinic Journal saieoaa ,!!)7 24442004 ..'rgement <>1 (hr blood vessels in the lung with ahy areas of atelectasis and minima! edema. kidneys showed minimal degenerative ages in tile epithelium of the mnvollilril tn- Tiie ti'st 111im:iis surviving this exposure urn' r/(it'/'d iii two weeks. On gross examination, .gcstion of the lungs was present, in nil species, ; it was mini' marked in thr min' nml rats than ilie guinea pigs. I lislelngiently, their was evii.t of pulmonary enngest.imi in exposed anik Some fatty infiltration was present, in the r of one rat. All other tissues studied appeared Thirty I'cr Cent Vinyl CMorvlc: Gross oxaminna of the animals whieli died as a result, of this sure revealed congestion of the ilings with aionhaeie areas. 'Pile min' and rats in addition .lied eougestion of the liver anil kidney. The .guinea pin death was delayed. Ill this animal ie was marked congestion of the lungs with i. 'in ham's and (lie liver was distended and very I'ie. Tin' mierosi'iipit' changes in the aiiimals , li died imdnded marked engorgement ol the /nonary blond vessels with edema and liemornrs in (lie limns. 'Phe t.rneliea of one rat. showed - rlieial desipiamatiou of the epithelium. Cim.-inm was also evident in the liver and kidney die miee ami rats. The liver of the guinea pig ,;di had the delayed death showed severe fatty ..Herat ion of the liver confirmed with frozen lions stained with Sudan III. Tiie four surviving guinea, pigs were saerifieed i weeks later. Marked pulmonary congestion ' ini'sent, with hemonhagie areas and edema. .iio ease there was evidence of secondary bae;.u infiltration. 'Pile liver in these guinea pigs r the appearance of fatty infiltration but no was demonstrated on frozen section. I'rr Crtil Vinyl Chlnriilr: One of five am pigs exposed to this concentration died nag the exposure ami another died within 24 ;r- The two which died showed marked connmi of the lungs with hemorrhages on gross i/iiiiation. This was also evident on micropie examination. The liver of one of these gave appearance of fatty infiltration, but no fat .1.1 Ik- demonstrated on frozen section. Thr three surviving guinea pigs were saerifieed ' weeks later. .Marked congestion of the lungs li hemorrhage was evident oil Isith the gross i microscopic examination. In one guinea, pig, n,'/client epithelium was completely absent, i'atliologieal studies which' were made of the ii. heart, spleen, adrenals, lymph nodes and /yes showed no difference between controls animals dying as a result of exposure or ben controls and the surviving animals sacri ficed two w/'i'ks after exposure. There was a tendency for tin' bliss I to remain uncloth'd in the animals /lying /luring exposure. This feature was niiled m the l.ivo hwmuii fatalities mentioned ear lier lint. it. is nut a speeilie characteristic of vinyl /'hlni'i/le. Discussion Tl/e resp/iiis/' nl guinea pigs to inhabit ion of vinyl chloride was similar to that re|mrted liv 1'atty, Yaiit, am! Waite. The guinea pigs in our study, however, tolerated a greater exposure dur ing the experimental period than either the mice or rats. The results in miee agreed closely with those reported by Peoples and Jg'ako. Rats were similar to miee in their response. The pathological changes in animals which died as a result of exposure were mainly those of vascular engorgement. of the lungs with hemor rhages and edema. The severity of these changes varied with I In' severit y of exposure, lutin' higher eoueeut rat ions, pulmonary ehange was marked villi severe damage in the trneheat epithelium, t `oiigestion ol the hver and kidneys also occurred in lest animals. These changes are similar to thus/' reported by I'aU.v and associates. Kvidenec of pulmonary congestion was still present in surviving animals sacrificed two weeks after exposure. I'at.ty and associates reported that such changes had disappeared in .'ibiiut eight days Degenerative changes in the tubular epithelium of the kidney were noted in one mouse dying as a result of exposure and in one mouse saerifieed two weeks after being exposed, Such changes, however, were minimal and not shown by other animals in the group. One of the guinea pigs with delayed death fol lowing exposure showed severe fatty infiltration of the liver. Changes suggestive of fatty infiltra tion were observed in other exposed animals but not eonfirined by frozen sections stained with Sudan III. Summary Separate groups of laboratory animals com prising five mice, five rats and five guinea pigs were exposed in an inhalation chamber to concen trations of 10, 21) and 30 per cent vinyl chloride in air for 30 minutes. An additional five guinea pigs were eXjHised to a 40 per cent concentration for a similar period of time.. The response by each of the three, species to these concentrations is noted. Inhalation of these relatively high concentra tions produeed narcosis and death. Mice were the most susceptible with guinea pigs considerably more resistant. Rats were similar to mice in their 39S October, ]: response. Exposure to ten per cent vinyl chloride in air produced deep narcosis in mice and rats but no deaths; 30 per cent concentrations killed mice and rats. Exposure of guinea pigs to 20 per cent produced deep narcosis; but three of five guinea pigs survived exposure to '10 per cent con centration. Animals dying as a result of exposure were autopsied shortly after death. Survivors and con trol animals were sacrificed two weeks later. Gross pathological and microscopic studies were done and these findings are described. The principal pathological changes in animals dying from exposure were congestion of the lungs with pulmonary edema and hemorrhages in some, and congestion of the liver and kidneys. Failure of the blood to clot was also observed. One of the three guinea pigs which died following exposure showed severe fatty infiltration of the liver. Survivors sacrificed two weeks after exposure showed little difference from the control animals. Pulmonary congestion was still evident but liver and kidney congestion was not. References 1. Danziger, H.: Accidental Poisoning by Vinyl Chlorwport of Two Cases, Canadian Med. Assoc. J. $2: \; 1960). 2. Patty, F. A., W. P. Yant, and C. P. Waite: Acute K. of Guinea Pigs to Vaj>ors of Some New Com therein! Compounds V. Vinyl Chloride, Rub. Health /Opt. .' (August 1930). 3. PkoiMjKh, A. S., and C. D. Leake: Thu Anesthetic Am: Vinyl Chloride, J. Rhartnacologtf 48: 28} (1922). 4. Lehmann, K. B., & F. Fluky; Toxicology and H'.yif.' Industrial Solvents, Translated by K. King arid II. !'. S Jr., Williams & Wilkins, Baltimore (1U-13). 5. .Schaumann, O.: Cited by Lehmann, K. B. and Y. 11 :r. 6. Osteu, R. 11., C. J. C.utu, J. C. Kuantz, and M J. s\ . wai.d: Anesthesia XXVII. Narcosis with Vinyl r. Anesthesiology 8: 359 (1947). 7. Oahu, J., R. M. Ruruihon, J. F. Vitciia, andJ. C Kao-. Jr.: AucHthcsia XXIV. Chcmicul Constitution of H> i carbons and Cardiac Aulouiaticity, J. Pharm. and Theiap. 97: 1 (191UL 8. Annual Report of the Chief Inspector of Factories for tKc 1951, Ixuuloo : ll.M.S.O. Oimi. 8772 (March 1953). 9. Hahuim, 1). K.: Health Problems in the Manufacture Use of Plastics, Brit. J. hid. Med. 10: 255 (1953). 10. Filatova, (J. S , and K. S. Ghonmukho: Hygienic Work.:* Conditions in Polyvinyl Chloride Tar Plants. Gioin^ ;; 38--12 (January 1957). Abstracted in Abst. of World Mtd. - 69 (July 1957). ? Back Issues of AIIIA Quarteuly FOR 18 YEARS THE AIIIA QUARTERLY was the publication of AIIIA, then in 1958 it was changed to be the AIIIA Journal with six issues per year instead of four. Now limitation of storage space is forcing us to dispose of all back issues of the Quarterly. For individual issues <|iiantities on hand vary from a low of S upward. All i.-.-ues except March 10-l(i (Vol. 7, Xo. 1) and .lime 1950 (Vol. 17, XTo. 2) arc available as we go to press. Some issues arc reprinted without cover. The cost is SI.50 per issue (Sl.OtJ each when more than three issues arc ordered) from Volumes 7 through 18. From 10-10 to 1040 AIIIA Quarterly appeared as a seetiou in Industrial Medicine and Surgery, however these issues of these sections have been reprinted and are available as a unit. The complete reprint, Vols. 1-7, costs $10.00 lo members, ami S50.00 to companies or departments of government.. Handsomely bound,'complete sets of Vols. 1 -- 1 Si with cmnul.'O ivo index are available for S250.00 per set. Address all orders lo: George I). Clayton, Executive Secretary, AIIIA, 14125 I'rcvo-t, Detroit 27, Michigan. (Hack i.-sues of AIIIA .luuniiil, 195S to present, may In' obtained directly, from our publisher, The Williams A Wilkins Company, -Il'S K. IVeston, !tallimore 2, .Maryland, at S!.",<) cadi issue.) r Introd t;i ;iiul ' thalli Tlic to it> u<ol :il>o ' cpttr: t t< *11 An nuini thitili tiilcMiltT the t 1:11 It I! t n! m m-- la i i"*ir tin-.- Exp T t: 1 1 I : Cm BFG31176 : o o cn