Document kDEaLG3NzzLOGKZXd0wxb38OJ

Current Intelligence Background Information on Trichloroethylene See also p- J. William Lloyd, Sc.D., Roscoe M. Moore, Jr., D.V.M., Patricia Breslin, Sc.D. Preliminary evaluation of the carcinogenic activity of trichloroethylene in laboratory rodents by the National Cancer Institute indicates that this material is a potent liver carcinogen. Trichloroethylene is a significant commercial product with a wide variety of industrial uses. In light of the potential risks of human exposure in the work environment, the National Institute for Occupational Safety and Health (NIOSH) is alerting the occupational health community to these findings. Additional animal studies as well as detailed epidemiologic investigations are anticipated. v_/n March 21, 1975, the Associate Director for Carcinogenesis, National Cancer Institute (NCI) informed the DHEW Committee to Coordinate Toxicology and Related Programs of the possible carcinogenicity of trichloroeth ylene. Subsequently, NIOSH was in formed by the NCI that an unusual in cidence of hepatocellular carcinomas was observed in mice given trichloroeth ylene by gastric intubation. Because of the extensive use of trichloroethylene in the work environment and the potential for cancer induction in humans, NIOSH is alerting the occupational health com munity as an integral part of its current intelligence system. Background Information Trichloroethylene (TCE) is a colorless, volatile, nonflammable liquid that is im miscible in water with a vapor density of 4 45 and a boiling point of 87C It is miscible with alcohol, chloroform, and ether, and dissolves most fixed and volatile oils. Trichloroethylene has a powerful soivent action for fats, greases, and Dr Lloyd is Director. Office of Occupational Health Surveillance and Biometrics, NIOSH, 5600 fishers Lane, Rockville, MD 20852. Drs. Moore and Breslin are staff members. Office ctuPaiional Health Surveillance and Brometrics. waxes, and it is one of the most im portant chlorinated solvents for use in degreasing and dryeleaning. Over 90% of TCE is consumed by the metal degreasing and drycleaning trades.1 It is also used as an ingredient in printing inks, paints, lacquers, varnishes, and adhesives.2 Trichloroethylene is used in minor quantities in a number of miscellaneous commercial products (see Table). A pharmaceutical grade of trichloro ethylene is used as a general anesthetic in surgical and obstetrical procedures and as an analgesic in the treatment of trigeminal neuralgia.3 TCE also has been used as an analgesic in dentistry for ex tractions, incisions of furuncles, and other short operative procedures.4 In ad dition, TCE is used in the extraction of caffeine for decaffeinated coffee.5 Trichloroethylene was first produced in 1864 by Fischer, but did not receive much attention as a potential chemical product until the early 1900's. It has been produced in the United States since 1925.1 Trichloroethylene is produced from acetylene and ethylene; however, the amount produced from acetylene has been steadily declining. It is estimated that 85% of TCE was produced from acetylene in 1967 as compared with 51% in 1971.s Journal of Occupational Medicine/Vol. 17, No. 9/September 1975 Toxicity Human. -- The predominant physio logical response is one of central ner vous system depression. This is particu larly true as a response from acute expo sure. Visual disturbances, mental confu sion, fatigue, and sometimes nausea and vomiting have been observed. The dangers of acute exposure to trichloro ethylene may be accentuated by visual disturbances and incoordination, which may lead to poor manual manipulation and, therefore, unsafe mechanical operation.6 Prolonged skin contact may cause local irritation and blister formation and, under industrial conditions, intermittent, repeated immersion of the hands in TCE has caused paralysis of the fingers.7 While TCE will penetrate the intact skin, it is considered unlikely that absorption of toxic quantities would occur by this route.8 Trichloroethylene is absorbed readily from the gastrointestinal tract, leading to respiratory failure or cardiac arrest causing death. Depending on the dose, signs and symptoms of toxicity may be delayed for several hours.4 Anesthetic doses frequently cause tachycardia or bradycardia and tachyp nea. Cardiac arrhythmias are common but convulsions are rare.4 Trichloroethyl- SL 026863 603 RtpnsMbbw ComiMftuI Products Containing Trichleroothytoflo Brush Too Spot Remom, Rmutart" - Chlorioatad hydrocarbon-. (OCtdar) (Product Salts Co.) (tricfeforoetliyteM) Methylcnt chloride Espeool 2530 (iyte) B7% - Pttroltuip distillate - Triedioroeltiyltnt TrichtoroethylaM 10 Wool hour Cuttoobu acetate Perdiloroelhyltfi* Metlfyluiw chlorid* , 15 15 Glamortot Rut Clatner (Glamomnt Products Corp.) Was Freon propsitent Brush Tup Spot Remow, Supsru :- . (Product Salts Co.) Ethyhst dicWoriOt 100% chlonoaltd sohmts Heaup paphths Tritthao* (l.l.l-trictikmutkwit) Hehnuc Spot Pie-Up 50% PerutA-Cfor HA - (DetrM Corp.) Tridlloroethylait Stars Air Fmhentr Methyltw chteridt Carbon*Qtanini (Halims Products Corp) Porchlortthyltns Stars Odor Neutraliiar (Stars, Roehudi ACa.). . Methylona ctdorido' ' TridMoroathytena-- .** 1 /' ,4 "4 2S-J1S' 552% 10.4 - TricMorotteyteot . Woumt Hmter x^y;- Trichloroethyltm . -34.5 ____ . ............. PMntMM i^ssaff. .., , rrotectiupsea) ter ptuntd arutij;;.__ ..y,-., ;; .y. dantepd rtra~a-a.o~d sih.w-bsi-.M~i;;i..y,;..S* pot CtouH-yvf............ . Carbon* No. 10 SpmiaT'Spat Rtmoutr .''(H/UabnbLaLrudi-illlar.llTl. KChLa~m. (C*o- .a) "_.v-va-v-,,"' MfOS, M fllk-^fTM spot TNIQW " (Carbon* Pioducts-CteJOffiS^^ Asphaltonr4^^\^2wfeffi^';J"'5* **);..w.,\ ' T,`. l.l,l-tridib)eodln*-:r;.^^^i.lOsy. Potolu*ip dte..f,,* . . ptc*||n,neM|lH<|te 'V ' Triddorotthyltn*' '-'g-S^^^'-<0^fe?'Phnylnittcay.oltat.ix:S^^^gig~i!.t'i*,><,(tlll^l*,**',>>";^*:^f Petroteune hydrvo-caibona^^ -e | wr 7-yi?.y v';i- r?w rms_i-hr-O M ms-p--f-i-y pSp-ojt N-M---n-M--Ci'v^r^^^rteV^wu ' DrthkirodilluwwMthariti ,: < ^ Paredkhlorobefuene . ^ . fPifiiijcj b%\'rri.: ^ -Uneiin - I.t.t-TricMorauriteH*CiWMH'- . '/-m Bit#.#*' Intent Chimnty - iv I.l.j-trichlofoetliaiie Freon-11 -v.# Crates- 2X and 3X (Mitad* Atbesins) -^*S^?5&,5.Surfae* dsmlaction. prasenotion " 1v _ '- %wA - and doodordiot ? ;-. . . (Ttsacar Int). ' Y LjgAjf Petroieui* lobricatint ait -T.. ' T. n.d. dorootbytene^- ^N'- ' M ^Rpyat Bond. >t> .. Tridilo.oathyltm..:,:,;^^>;-^.;;TM 41 -. Chloroform ...., . ..... nPint ter..-....._ (Fraen) - - Rerosano '-'x'v-y:-` :'*^'.,^-!*"aCamphor'^.`--.v;Xi\iv.;i' , , DuPont Dry Clan *. .y?X-*yj Y,' Jvf SQMMf ' -vt.-Ae-d - Irichloroathylme , ' . , . .... (do Pont) , . Trichlototthyltm 'J- ; (Joy Choor, lot) "" Tried Metal Cleaner . Trichloroethylene -' du, Kwik Kleon-Drot Shampoo* Water RtpeHont ' '* :iy:?y Viy Dry Shampoo- Tried Metal Polish (Oetrm Corp.) .. . (Royot Bond, lot) , Trichloroethylene " Piccotes 120 Solution . 25l%- Triehlatoethylaiio *;r; Tricolor (synthetic rtsin) '` ' lash Bath - Solvent ' Was (paraHin) . \ - Claaosar hr. (also eyelashes (P.P.G. Industries, Chem. Div.) Trichlorotthyltnt I . (Renton) Trichloroethyloos 100% Glamwenr Dry Cteantr hr Roys ... NapMht (Formerly Gtemorene Wool Rut Cttaoer) Trichloroethylane ~ Trident Dry Clean (Glamoreno Products Corp.) 0'Cedsr SonSprayt No longer contains trichloroethylene but listed since some products may still be in use. +No longer marketed, but some may still be in use. The above product descriptmns are not to bo construed as current or accurate since changes in' product composition are being made continually by manufacturers. Source: Adapted hum Hull, J.E . Industrial Medicine. Vd. 40. p. 31. 1971. ene, when inhaled by pregnant women, diffuses rapidly across the placenta.9 Deliberate inhalation of moderate concentrations of TCE induces a state of euphoria which has led to addiction.1 10 Sniffing commercial products containing TCE is a method for getting "high" among adolescents.11 12 The disap pearance of disorientation, visual hallucinations, delusions, and other psy chotic symptoms coincides with a fall in urinary levels of trichloroethylene metabolites.10 It has been reported that the administration of glucose or insulin increases the amount and speed of ex- cretion of metabolites of TCE.13 Liver and kidney injuries attributed to overex posure to TCE are considered rare.14 However, severe injuries to both the liver and kidneys have been reported.1 To date there have been no published reports of any association between TCE and cancer in humans. Animal. -- Clinical experience from acute exposure in animals has come mainly from the use of TCE as an anesthetic. TCE has been used as an inhalation anesthetic for a variety of animals. It has also been used as a disin fectant and detergent for the skin, minor 604 wounds, and surgical instruments 4 Death in laboratory animals from an acute exposure to TCE vapor may result from respiratory failure or cardiac arrest.6 15 Trichloroethylene is reported to have direct action on the bone marrow of rabbits causing myelotoxic anemia,16 It causes residual brain damage in rats,17 and produces liver and kidney changes and growth depression in a variety of laboratory animals 6 The National Cancer Institute (NCI) tested trichloroethylene by gastric in tubation in both sexes of Osborne Men del rats and B6C3F mice. Two dose levels were given in each animal group, five times weekly. Both sexes of rats were given either 1000 mg/kg or 500 mg/kg doses. Male mice were given 2400 mg/kg or 1200 mg/kg doses; female mice were given 1800 mg/kg or 900 mg/kg doses. No hepatocellular car cinomas were seen in the rats; 30 of 98 (30.6%) of the mice given the low dose, and 41 of 95 (43.2%) of the mice given the higher dose had hepatocellular car cinomas. Only one of 40 (2.5%) control mice developed these carcinomas,19 It should be noted that the National Cancer Institute information is the first report associating TCE with cancer in animals. Permissible Occupational Expo sures The current Occupational Safety and Health Administration, Department of Labor standard for trichloroethylene is 100 ppm (525 mg/m3) and is based on the threshold limit value established by the American Conference of Govern mental Industrial Hygienists.18 On July 23, 1973, the National In stitute for Occupational Safety and Health transmitted criteria for a recom mended standard on trichloroethylene to the Department of Labor. Producers and Suppliers The following is a list of the major producers and suppliers of trichloroeth ylene in the United States:* Diamond Shamrock Corp., Electro Chems. Div., Deer Park, TX; Dow Chemical U.S.A., Freeport, TX; Ethyl Corp., Baton Rouge, LA; Occidental Petroleum Corp., Hooker Chem. Corp., subsid.. Electrochemical & Specialities Div., Taft, I A; PPG Indust,, Inc., Chem. Div., Indust. Chem. Div., Lake Charles, LA. Source: Adapted from the 1974 Directory of Chemical Producers, USA, Stanford Research In stitute, Menlo Park, California, 1974. Trichloroethylene/Lloyd, Moore, Breslin SL 026864 i; 4 t *v Occupational Exposure Estimated Number of Workers Ex posed to Trichloroethylene by Industry Industry Agricultural Services Oil and Gas Extraction Ordnance Estimated Number Exposed* 124 267 57 Food Products Textile Mill Products 2,502 1,014 Apparel/Textile Products Lumber Products Furniture Mfg. Paper Products Mfg. Printing Trades Chemical Mfg. Petroleum Products Rubber/Plastics Mfg. Leather Products Stone/Clay Products Primary Steel Mfg. Metal Fabrication Machinery Mfg. Electrical Equipment Transportation Equipment 858 72 162 2,240 2,876 9,552 713 4,985 725 2,685 11,672 11,709 7,481 66,727 54,174 Instrument Mfg. Miscellaneous Mfg. Trucking/Warehousing Air Transportation Communication Wholesale Trade Automotive Dealer Furniture Stores Banking Personal Services Misc. Business Services Auto Repair Misc. Repair Amusement Services Mechanical Services Misc. Unclassified 4,815 1,516 642 23 5,560 3,327 223 597 2,391 583 27,759 5,246 17,198 7,987 20,053 4,138 Estimated Total 282,653 Projections based on preliminary data obtained from the National Occupational Hazard Survey, Hazard Surveillance Branch, Office of Occupational Health Surveillance and Biometrics, NIOSH. (Does not include anesthetic use or use in tradename products.) Anesthesia Survey It is estimated that approximately 5,000 medical, dental, and hospital per sonnel are routinely exposed to trichlo roethylene as an anesthetic gas.20 Epidemiologic Studies The Division of Field Studies and Clinical Investigations, NIOSH, is at tempting to identify human populations at risk of trichloroethylene exposures for epidemiologic study. References 1. Kirk-Othmer Encyclopedia of Chemical Technology. )ohn Wiley and Sons, Inc., New York, Vol. V, p 183, 1964. 2. Stewart RD, Hake CL, and Paterson JE: The use of breath analysis to monitor trichlo roethylene exposures. Arch Environ Hlth 29:613, 1974, 3. Massite J: Trichloroethylene. /OM 16:194197, 1974. 4. Huff IE: New evidence on the old prob lems of Trichloroethylene. Ind Med 40:25-33, 1971. 5. Blackford IL: Trichloroethylene. Chemical Economics Handbook, Stanford Research In stitute, Menlo Park, California, Organic Chemical, Vol. P-Z, -p 697.3031A, 1972. 6. Patty FR: Industrial Hygiene and Toxicology. Interscience Publishers, New York, Vol. II, pp 1309-1313, 1963. 7. McBirney RS: Trichloroethylene and dichloroethylene poisoning. Arch Ind Hyg Occup Med 10:130-33, 1954. B. Stewart RO and Dodd HC: Absorption of carbon tetrachloride, trichloroethylene, tetrachloroethylene, methylene chloride, and 1,1,1- trichloroethane through the human skin Am Ind Hyg Assoc / 25:439-64, 1964. 9. Laham $: Studies on placental transfer tri chloroethylene. Ind Med 39:46-9, 1970 10. Ikeda M, Ohtsuji H, Kawai H, and Kumyoshi M: Excretion kinetics of urinary metabolites in a patient addicted to trichloro ethylene. Brit I Industr Med 28:203-06, 1971. 11. Lttt IF and Cohen Ml: Danger -- vapor harmful spot-remover sniffing. New Eng / Med 281:543-44, 1969. 12. Hepple NV: Sniffing of a shoe-cleaner. Brit Med }, (Nov 9). p 387, 1968. 13. Soucek B and Vlachova D: Excretion of trichloroethylene metabolites in human urine. Brit I Industr Med 17:60-66, 1959. 14. Stewart RD, Dodd HC, Gay HH and Duncan SE: Experimental human exposure to trichloroethylene. Arch Environ Hlth 20:64-71, 1970. 15. Mikiskova H and Mikiska A: Some electrophysiological methods for studying the ac tion of narcotic agents in animals, with special reference to industrial solvents: A review. Brit I Industr Med 25:81-105, 1968. 16. Mazza V and Brancaccio A: Charac teristics of the formal elements of the blood and bone marrow in experimental trichloro ethylene intoxication. Folia Med 50:318-24, 1967. 17. Baetjer AM, Annau Z, and Abbey H: Water deprivation and trichloroethylene -- Ef fects on hypothalamic self-stimulation. Arch Environ Hlth 20.712-19, 1970. 18. Documentation of the Threshold Limit Values for Substances in Workroom Air. American Conference of Governmental In dustrial Hygienists, Cincinnati, Ohio, 3rd Edition, pp 263-65, 1971. 19. Unpublished preliminary report issued by the National Cancer Institute (NCI), 1975. Requests for further information available from NCI, Bethesda, MD, 20. 1974 Hospital Inhalation Producer Survey, conducted by the Division of Field Studies and Clinical Investigations, NIOSH, and a personal communication from a representative of the American Dental Associ ation, 1975. Journal of Occupational Medicine/Vol. 17, No. 9/September 1975 SL 26865 605