National Toxicology Program

Selected toxicity information from HSDB, one of the National Library of Medicine's databases. ¹

Names (NTP)

• 3-Chloro-2-methylpropene
• 3-CHLORO-2-METHYL-1-PROPENE

Human Toxicity Excerpts

• SYMPTOMATOLOGY: 1. A. INHALATION, HIGH VAPOR CONCN: GASPING, REFUSAL TO BREATHE, COUGHING, SUBSTERNAL PAIN, & EXTREME RESP DISTRESS @ ... CONCN OVER 1500 PPM. IRRITATION OF EYES & UPPER RESP MUCOSA APPEARS PROMPTLY AFTER EXPOSURE TO CONCENTRATED VAPORS. LACRIMATION AND HEADACHE ARE PROMINENT. COMA MAY OCCUR RAPIDLY. B. INHALATION, LOW VAPOR CONCN: CENTRAL NERVOUS DEPRESSION & MODERATE IRRITATION OF RESP SYSTEM. 2. DERMAL: SEVERE SKIN IRRITATION WITH MARKED INFLAMMATORY RESPONSE OF EPIDERMIS & UNDERLYING TISSUES. /DICHLOROPROPENES/ [Gosselin, R.E., R.P. Smith, H.C. Hodge. Clinical Toxicology of Commercial Products. 5th ed. Baltimore: Williams and Wilkins, 1984., p. II-167]**PEER REVIEWED**
  
• SYMPTOMATOLOGY: 3. ORAL: ACUTE GI DISTRESS WITH PULMONARY CONGESTION & EDEMA. CNS DEPRESSION, PERHAPS EVEN IN ABSENCE OF IMPAIRED OXYGEN UPTAKE. 4. BY ANY ROUTE, POSSIBLE INJURIES TO LIVER, KIDNEYS & HEART. /DICHLOROPROPENES/ [Gosselin, R.E., R.P. Smith, H.C. Hodge. Clinical Toxicology of Commercial Products. 5th ed. Baltimore: Williams and Wilkins, 1984., p. II-167]**PEER REVIEWED**
  

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Non-Human Toxicity Excerpts

• LC50 VALUES OF METHALLYL CHLORIDE INHALED BY MICE & RATS WERE 57.0 & 34.5 MG/L, RESPECTIVELY. DECR IN LEVELS OF SULFHYDRYL & DISULFIDE GROUPS IN BLOOD & LIVER WAS OBSERVED IN RATS EXPOSED AT 10 MOLES/L. [BAKHISHEV GN ET AL; FIZIOL AKT VESHCHESTVA 6: 98-100 (1974)]**PEER REVIEWED**
  
• TOXICITY OF ALIPHATIC HALOHYDROCARBONS TO RATS EXPOSED TO THEIR VAPORS FOR 30 MIN DECR IN FOLLOWING ORDER: METHYL BROMIDE, 1,2-DIBROMOETHANE, METHALLYL CHLORIDE. LD50 CONCN RANGED BETWEEN 11.0 & 152 MG/L. [BAKHISHEV GN; FARMAKOL TOKSIKOL 8: 140-2 (1973)]**PEER REVIEWED**
  
• Test results positive for mutagenicity in mouse lymphoma cells. [NIOSH; Current Awareness Listing (1985)]**PEER REVIEWED**
  
• Mutagenic to Salmonella typhimurium strain TA100 with or without rat liver S9 mix in 0-3 umol/ml doses in liquid suspension. [Neudecker T et al; Pharmacol 29: 2611-7 (1980) and Eder E et al; Chem Biol Interact 38: 303-15 (1982)]**PEER REVIEWED**
  
• ... Methallyl chloride was tested against Tyrophagus longior, Acarus siro, and Glycyphagus destructor, at 10 and 20 deg C in the lab. ... Ct (concn times time) values were established. The eggs, especially of T longior, showed high tolerance. The most active cmpd, in decreasing order, were acrylonitrile, ethylene dibromide, Me formate, ethylene dichloride, carbon tetrachloride, and Me chloroform. ... Due to the resistance of eggs, two treatments at 5-9 wk intervals were required. [Bowley CR, Bell CH; J Stored Prod Res 17 (2): 83-7 (1981)]**PEER REVIEWED**
  
• Thirteen allylic cmpd, mostly with close structural relation, were tested for their ability to induce unscheduled DNA synthesis (UDS) in HeLa cells and mutations in the Ames test; 11 induced UDS dose dependently. ... Among structural analogs and typical allylic cmpd with various leaving groups, the amount of induced DNA repair at equimolar concn decreased in the same order as the mutagenic and alkylating activities in the other 2 test systems: cis-1,3-dichloropropene > trans-1,3-dichloropropene > 2,3-dichloro-1-propene; 1-chloro-2-butene > 3-chloro-1-butene > 3-chloro-2-methyl-1-propene > allyl chloride; allyl methanesulfonate > allyl iodide > allyl bromide > allyl chloride. [Schiffman D et al; Cancer Lett (Shannon, Irel) 20 (3): 263-9 (1983)]**PEER REVIEWED**
  
• Twenty-seven chemicals (including 3-chloro-2-methyl-1-propene) previously tested in rodent carcinogenicity assays were tested for induction of chromosomal aberrations and sister chromatid exchanges (SCE) in Chinese hamster ovary cells as part of a larger analysis of the correlation between results of in vitro genetic toxicity assays and carcinogenicity bioassays. Chemicals were tested up to toxic doses with and without exogenous metabolic activation. 3-Chloro-2-methyl-1-propene induced sister chromatid exchanges in cultured Chinese hamster ovary cells at 16-200 ug/ml, both in the presence and absence of S9. In the absence of S9, in vitro treatment of Chinese hamster ovary cells with 120 ug/ml or more of this chemical also produced chromosomal aberrations; treatment results in the presence of S9 were questionable because the increases in aberrations occurred only in one trial at the highest nontoxic dose tested (200 ug/ml), and the aberrations were all observed as pulverized chromosomes. [Gulati DK et al; Environ Mol Mutagen 13 (2): 133-93 (1989)]**PEER REVIEWED**
  
• Groups of 50 male and 50 female B6C3F1 mice, eight weeks of age, were administered 3-chloro-2-methylpropene (technical-grade, containing 5% dimethylvinyl chloride (1-chloro-2-methylpropene) in corn oil by gavage at doses of 0, 100 or 200 mg/kg body weight on five days per week for 103 weeks. Survival in the treated groups was not significantly lower than that in vehicle controls; the numbers of survivors at the end of the experiment were: 26 male controls, 37 at the low dose and 32 at the high dose; and 37 female controls, 43 at the low dose and 27 at the high dose. Histopathological evaluation revealed dose-related increased incidences (by the incidental tumor test) of forestomach neoplasms in males and females. In males, the incidences of squamous-cell papillomas were 3/49 controls, 19/49 (p< 0.001) at the low dose and 30/49 (p< 0.001) at the high dose; the incidence of squamous-cell carcinomas were 0/49 controls, 5/49 (p= 0.031) at the low dose and 7/49 (p= 0.016) at the high dose; and the combined incidences of squamous-cell papillomas or carcinomas were 3/49 controls, 24/49 (p< 0.001) at the low dose and 36/49 (p< 0.001) at the high dose. In females, the incidences of squamous-cell papillomas were 0/50 controls, 15/48 (p< 0.001) at the low dose and 29/44 (p< 0.001) at the high dose; the incidences of squamous-cell carcinomas were: 0/50 controls, 1/48 at the low dose and 2/44 at the high dose; and the combined incidences of squamous-cell papillomas or carcinomas were 0/50 controls, 16/48 (p<0.001) at the low dose and 31/44 (p< 0.001) at the high dose. The incidences of epithelial hyperplasia were also increase in treated animals: males - 0/49 controls, 14/49 at the low dose and 15/49 at the high dose; females - 4/50 controls, 6/48 at the low dose and 13/44 at the high dose. [IARC. Monographs on the Evaluation of the Carcinogenic Risk of Chemicals to Man. Geneva: World Health Organization, International Agency for Research on Cancer, 1972-PRESENT. (Multivolume work)., p. V63 327 (1995)]**PEER REVIEWED**
  
• Groups of 50 male and 50 female Fischer 344/N rats, eight weeks of age, were administered 3-chloro-2-methylpropene (technical grade, containing 5% dimethylvinyl chloride) in corn oil by gavage at doses of 0, 75 or 150 mg/kg body weight on five days per week for 103 weeks. Survival was marginally reduced among male rats receiving the high dose; the numbers of survivors at the end of the experiment were 30 male controls, 25 at the low dose and 17 at the high dose; and 31 female controls, 32 at the low dose and 26 at the high dose. Histopathological examination revealed increased incidences (by the incidental tumor test) of squamous-cell papillomas of the forestomach in animals of each sex receiving the high dose: 1/50 male controls, 5/50 at the low dose and 30/48 (p< 0.001) at the high dose; 1/50 female controls, 1/50 at the low dose and 10/50 (p= 0.006) at the high dose. the incidences of basal-cell or epithelial hyperplasia of the forestomach were also increased in treated animals: 19/50 male controls, 41/50 at the low dose and 44/48 at the high dose; 24/50 female controls, 42/50 at the low dose and 45/50 at the high dose. [IARC. Monographs on the Evaluation of the Carcinogenic Risk of Chemicals to Man. Geneva: World Health Organization, International Agency for Research on Cancer, 1972-PRESENT. (Multivolume work)., p. V63 328 (1995)]**PEER REVIEWED**
  
• Groups of 10 male and 10 female Fischer 344/N rats were administered 0, 50, 100, 200, 300, or 400 mg/kg body weight 3-chloro-2-methylpropene (purity, 93%; containing 5% 1-chloro-2-methylpropene) in corn oil by gavage on five days per week for 13 weeks. Groups of 10 male and 10 female B6C3F1 mice received 0, 125, 250, 500, 750, or 1250 mg/kg body weight by the same schedule. Focal areas of necrosis with inflammation were noted in the livers of rats given 300 and 400 mg/kg body weight. In mice, degeneration and necrosis of the cortical tubules of the kidneys were observed at doses of 500 mg/kg body weight and higher, and the incidence and severity of these lesions were greater in males than in females. Coagulative necrosis in the liver was also observed in mice at doses of 500 mg/kg body weight and higher. [IARC. Monographs on the Evaluation of the Carcinogenic Risk of Chemicals to Man. Geneva: World Health Organization, International Agency for Research on Cancer, 1972-PRESENT. (Multivolume work)., p. V63 329 (1995)]**PEER REVIEWED**
  
• In a study of cell proliferation in the forestomach, 3-chloro-2-methylpropene (purity, 90%; most of the remainder was 1-chloro-2-methylpropene) was administered by gavage to groups of eight male Fischer 344/N rats at doses of 0, 75 or 160 mg/kg body weight on five days per week for two weeks. All treated animals had generalized epithelial cell proliferation and hyperkeratosis of the forestomach. [IARC. Monographs on the Evaluation of the Carcinogenic Risk of Chemicals to Man. Geneva: World Health Organization, International Agency for Research on Cancer, 1972-PRESENT. (Multivolume work)., p. V63 329 (1995)]**PEER REVIEWED**
  
• 3-Chloro-2-methylpropene (purity, 90.7%) was mutagenic to Salmonella typhimurium strain TA100 both in the presence and absence of metabolic activation and when the cells were treated in a modified liquid suspension test or, as reported in an abstract, in chambers specially devised for volatile compounds. A 100% pure preparation was also mutagenic to this strain. In standard assays, the compound was more weakly mutagenic to TA100; it was mutagenic to TA1537 only in the presence of an exogenous metabolic system. [IARC. Monographs on the Evaluation of the Carcinogenic Risk of Chemicals to Man. Geneva: World Health Organization, International Agency for Research on Cancer, 1972-PRESENT. (Multivolume work)., p. V63 329 (1995)]**PEER REVIEWED**
  
• Induction of somatic recombination was observed in Drosophila melanogaster, in the white/white+ eye mosaic assay, after larvae had been exposed by inhalation of 3-chloro-2-methylpropene of unknown purity. [IARC. Monographs on the Evaluation of the Carcinogenic Risk of Chemicals to Man. Geneva: World Health Organization, International Agency for Research on Cancer, 1972-PRESENT. (Multivolume work)., p. V63 331 (1995)]**PEER REVIEWED**
  
• The frequencies of both large and small colonies in the L5178Y mouse lymphoma tk locus assay, indicative of intragenic changes at the thymidine kinase locus and chromosomal rearrangements, respectively, were increased by treatment with 3-chloro-2-methylpropene (purity, 90.7%) in the absence of metabolic activation. [IARC. Monographs on the Evaluation of the Carcinogenic Risk of Chemicals to Man. Geneva: World Health Organization, International Agency for Research on Cancer, 1972-PRESENT. (Multivolume work)., p. V63 331 (1995)]**PEER REVIEWED**
  
• 3-Chloro-2-methylpropene (purity, 90.7%) induced chromosomal aberrations and sister chromatid exchange in Chinese hamster ovary cells both in the presence and absence of metabolic activation. [IARC. Monographs on the Evaluation of the Carcinogenic Risk of Chemicals to Man. Geneva: World Health Organization, International Agency for Research on Cancer, 1972-PRESENT. (Multivolume work)., p. V63 331 (1995)]**PEER REVIEWED**
  
• Micronuclei were not induced in bone-marrow cells of male B6C3F1 mice treated intraperitoneally with 3-chloro-2-methylpropene (purity, 90.7%) at doses up to 250 mg/kg body weight. [IARC. Monographs on the Evaluation of the Carcinogenic Risk of Chemicals to Man. Geneva: World Health Organization, International Agency for Research on Cancer, 1972-PRESENT. (Multivolume work)., p. V63 331 (1995)]**PEER REVIEWED**
  
• ... Under the conditions of these two yr gavage studies, there was clear evidence of the carcinogenicity for 3-chloro-2-methylpropene as shown by the incr incidences of squamous cell neoplasms in the forestomach of male and female F344/N rats and of male and female B6C3F1 mice. [Toxicology & Carcinogenesis Studies of 3-Chloro-2-methylpropene in F344/N Rats and B6C3F1 Mice Technical Report Series No. 300 (1986) NIH Publication No. 86-2556 U.S. Department of Health and Human Services, National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709]**QC REVIEWED**
  

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Human Toxicity Values

• None found

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Non-Human Toxicity Values

• LC50 MOUSE 57.0 MG/L /30 MIN/ [BAKHISHEV GN ET AL; FIZIOL AKT VESHCHESTVA 6: 98-100 (1974)]**PEER REVIEWED**
  
• Salmonella typhimurium mutagenicity: Number of revertents per umol of test cmpd. With S-9 mix: 18 umol; Without S-9 mix: 44 umol. [Eder E et al; Chem Biol Interactions 38: 303-15 (1982)]**PEER REVIEWED**
  
• LC50 RAT 34.5 MG/L /30 MIN/ [BAKHISHEV GN ET AL; FIZIOL AKT VESHCHESTVA 6: 98-100 (1974)]**PEER REVIEWED**
  

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Absorption, Distribution and Excretion

• 2-(14)C 3-Chloro-2-methylpropene (specific activity, 2.5 mCi/umol; radiochemical purity, 93%; 5% 1-chloro-2-methylpropene) was administered by gavage to male Fischer 344 rats as single or up to four daily doses of 150 mg/kg body weight in corn oil. The compound was extensively absorbed and rapidly excreted: 82% of the single dose was eliminated within 24 hours after treatment. It was rapidly distributed to tissues, and the highest concentrations were found in forestomach, liver and kidney; the concentration of radiolabel was considerably lower in glandular stomach than in forestomach. The tissue concentrations were approximately doubled after two doses, but little additional increase was observed after four doses. The concentrations decreased after cessation of treatment. After a single dose, about 58% of the administered radiolabel was found in the urine, 22% was exhaled and 2% was detected in the feces. In the expired air, about 12% of the dose was (14)C-carbon dioxide and 7% was volatile compounds. [IARC. Monographs on the Evaluation of the Carcinogenic Risk of Chemicals to Man. Geneva: World Health Organization, International Agency for Research on Cancer, 1972-PRESENT. (Multivolume work)., p. V63 328 (1995)]**PEER REVIEWED**
  

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Metabolism/Metabolites

• The main urinary metabolite was N-acetyl-S-(2-methylpropenyl)cysteine, which constituted 45% of the total urinary radiolabel. This metabolite is presumed to arise from direct conjugation of glutathione with 3-chloro-2-methylpropene. [IARC. Monographs on the Evaluation of the Carcinogenic Risk of Chemicals to Man. Geneva: World Health Organization, International Agency for Research on Cancer, 1972-PRESENT. (Multivolume work)., p. V63 329 (1995)]**PEER REVIEWED**
  
• ... Daily doses of 150 mg/kg 2-(14)C-1-chloro-2-methylpropene (DMVC) or 2-(14)C-3-chloro-2-methylpropene (CMP) were admin to male Fischer 344 rats for 1, 2, or 4 consecutive days. One daily dose of 150 mg/kg DMVC was admin to male B6C3F1 mice. Both DMVC and CMP were rapidly metabolized; however, CMP was cleared at a slightly slower rate. Rats exhaled approx 25 and 10% of the DMVC and CMP as carbon dioxide, respectively. Mice exhaled 25% of the DMVC as carbon dioxide. Rats expired 30% of the admin DMVC unchanged in the 24 hr after dosing compared to only 7% of the admin CMP. Mice expired 5% of the admin DMVC in the same time period. ... The 24 hr urinary excretion in rats was 35% of the admin DMVC compared to 58% of CMP. Mice excreted 47% of the admin DMVC in 24 hr in the urine. An unusual metabolite of DMVC, 2-amino-6-methyl-4-thia-5-heptene-1,7-dioic acid was identified. [Ghanayem BI, Burka LT; Drug Metab Dispos 15 (1): 91-6 (1987)]**PEER REVIEWED**
  

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TSCA Test Submissions

• The ability of 3-chloro-2-methylpropene (CMP) to induce morphological transformation in the BALB/3T3 mouse cell line (Cell Transformation Assay) in the presence and absence of added metabolic activation by Aroclor-induced rat liver S9 fraction was evaluated. Based on preliminary clonal toxicity determinations (exposure time=2 hrs), CMP was tested at 0.03, 0.1, 0.3 and 1.0 ul/ml in the absence of activation (cell survival ranging from 100-77% relative to acetone solvent control), and at 0.10, 0.15, 0.20 and 0.25 ul/ml in the presence of added metabolic activation (cell survival ranging from 85% to <1%). Test material did not induce the appearance of a significant number of transformed foci.[Microbiological Associates; Activity of 3-Chloro-2-methylpropene in the Morphological Transformation of BALB/3T3 Mouse Embryo Cells in the Absence and Presence of Exogenous Metabolic Activation, Final Report. (1985), EPA Document No. FYI-OTS-1085-0396, Fiche No. OTS0000396-1 ]**UNREVIEWED**
  
• The ability of 3-chloro-2-methylpropene (CMP) to induce morphological transformation in the BALB/3T3 mouse cell line (Cell Transformation Assay) in the presence and absence of added metabolic activation by Aroclor-induced rat liver S9 fraction was evaluated. Based on preliminary clonal toxicity determinations (exposure time=2 hrs), CMP was tested at 0.03, 0.1, 0.3 and 1.0 ul/ml in the absence of activation (cell survival ranging from 95-48% relative to acetone solvent control), and at 0.1, 0.18, 0.3 and 0.5 ul/ml in the presence of added metabolic activation (cell survival ranging from 124-48%). Test material did not induce the appearance of a significant number of transformed foci, although a marginal yet dose-responsive increase in transformation was observed in the assay with added metabolic activation.[Microbiological Associates; Activity of 3-Chloro-2-methylpropene in the Morphological Transformation of BALB/3T3 Mouse Embryo Cells in the Absence and Presence of Exogenous Metabolic Activation, Final Report. (1985), EPA Document No. FYI-OTS-1085-0396, Fiche No. OTS0000396-1 ]**UNREVIEWED**
  
• Toxicity of 1-chloro-2-methylpropene (CMP) with respect to testicular changes was evaluated in male albino Wistar rats (10/treated group, 20 in arachis oil vehicle control group) exposed orally to CMP by gavage at dosage levels of 0, 40 or 60 mg/kg/day for 14 days. On day 15, the animals were sent for pathological examination. Significant differences were observed between treated and control animals in the following: decreased maternal body weight and body weight gain (high-dose group), increased incidence of minor renal changes (increase in eosinophilic intra-cytoplasmic inclusion droplets in the proximal convoluted tubules, high-dose group), and increased incidence of gastric lesions, severe irritative changes in the stomach, and focal erosion of the cardiac mucosa with moderate hyperkeratosis and acanthosis in the stomach (both treated groups). No significant differences between treated and control animals were observed in the following: maternal mortality, clinical observations, testes weights, morphology, or detailed macroscopic and microscopic examination of the testes, epididymides, ductuli efferentes, and vasa deferentes.[Tunstall Lab, Shell Oil Co.; Toxicity of Fine Chemicals: Preliminary Studies for the Detection of Testicular Changes in Rats. (1979), EPA Document No. 878216424, Fiche No. OTS0510352 ]**UNREVIEWED**
  
• The mutagenicity of 3-chloro-2-methylpropene was evaluated in Salmonella tester strains TA1535, TA100, TA1537, TA1538 and TA98 (Ames test), both in the presence and absence of added metabolic activation by Aroclor-induced rat liver S9 fraction. 3-Chloro-2-methylpropene, diluted in DMSO, was tested at concentrations up to 100ul/plate using the plate incorporation technique. 3-Chloro-2-methylpropene did not cause a positive response in any tester strain with or without metabolic activation.[Microbiological Associates; Activity of 3-Chloro-2-methylpropene in the Salmonella/Microsomal Assay for Bacterial Mutagenicity, (1977), EPA Document No. FYI-OTS-0885-0396, Fiche No. OTS0000396-1 ]**UNREVIEWED**
  
• The mutagenicity of 3-chloro-2-methylpropene was evaluated in Salmonella tester strains TA98, TA100, TA1535, TA1537 and TA1538 (Ames Test), both in the presence and absence of added metabolic activation by Aroclor-induced rat liver S9 fraction. Based on preliminary toxicity determinations, 3-chloro-2-methylpropene, diluted in DMSO, was tested at concentrations up to 1,600ug/plate in the presence of metabolic activation and up 650ug/plate without metabolic activation using the preincubation technique. 3-Chloro-2-methylpropene did not cause a positive response in any tester strain with or without metabolic activation.[Microbiological Associates; Salmonella/Mammalian-Microsome Preincubation Mutagenicity Assay, (1984), EPA Document No. FYI-OTS-0885-0396, Fiche No. OTS0000396-1 ]**UNREVIEWED**
  
• The mutagenicity of methallyl chloride dimer was evaluated in Salmonella tester strains TA98, TA100, TA1535, TA1537 and TA1538 (Ames Test), both in the presence and absence of added metabolic activation by Aroclor-induced rat liver S9 fraction. Based on preliminary toxicity determinations, methallyl chloride dimer, diluted in DMSO, was tested at concentrations up to 2000ug/plate with metabolic activation and up to 1000ug/plate without metabolic activation using the plate incorporation technique. Methallyl chloride dimer did not cause a positive response in any tester strain with or without metabolic activation.[FMC Genetic Toxicology Laboratory; Salmonella/Mammalian-Microsome Plate Incorporation Mutagenicity Assay, (1985), EPA Document No. FYI-OTS-0885-0396, Fiche No. OTS0000396-1 ]**UNREVIEWED**
  
• The ability of 3-chloro-2-methylpropene (CMP) induce Sister Chromatid Exchange (SCE) in Chinese hamster ovary (CHO) cells was evaluated both in the presence and absence of Aroclor-induced rat liver S9 metabolic activation. Based on preliminary toxicity tests, CMP, diluted with DMSO, was tested at concentrations of 0, 25, 50, 75, 125 or 250 ug/ml without activation and at concentrations of 8, 20, 40, 60 or 80 ug/ml with activation. Fifty metaphases were scored/concentration. Nonactivated cultures treated with 50, 125, and 250 ug/ml exhibited SCE frequencies significantly greater than untreated controls (p < 0.05, t-test). An apparent dose-related response was observed, although cultures treated with 75 ug/ml did not exhibit a significant increase in the frequency of SCE. None of the activated cultures exhibited SCE frequencies significantly greater than solvent controls.[Pharmakon Research International, Inc.; In Vitro Sister Chromatid Exchange in Chinese Hamster Ovary (CHO) Cells with Methallyl Chloride. (1985), EPA Document No. FYI-OTS-1085-0396, Fiche No. OTS0000396-1 ]**UNREVIEWED**
  
• The ability of 3-chloro-2-methylpropene (technical grade, >95% purity) (CMP) induce Sister Chromatid Exchange (SCE) in Chinese hamster ovary (CHO) cells was evaluated both in the presence and absence of Aroclor-induced rat liver S9 metabolic activation. Based on preliminary toxicity tests, CMP, diluted with DMSO, was tested at concentrations of 0, 30, 75, 150, 200 or 300 ug/ml without activation and at concentrations of 8, 15, 25, 50, 75 or 110 ug/ml with activation. Fifty metaphases were scored/concentration (except for the highest concentrations due to excessive toxicity to the nonactivated cultures and to mitotic delay in the activated cultures). Nonactivated and activated cultures exhibited SCE frequencies which were statistically significantly greater than solvent controls at all concentrations tested (except the highest concentration for both nonactivated and activated cultures, p < 0.05, t-test). A dose-related response was observe with both the nonactivated and activated cultures.[Pharmakon Research International, Inc.; In Vitro Sister Chromatid Exchange in Chinese Hamster Ovary (CHO) Cells with Methallyl Chloride Technical. (1985), EPA Document No. FYI-OTS-1085-0396, Fiche No. OTS0000396-1 ]**UNREVIEWED**
  
• 3-Chloro-2-methylpropene (CAS# 563-47-3) was evaluated for acute oral toxicity. The test substance was administered by gavage to fasted male and female Sprague-Dawley rats (10/sex/group). Dosages and mortality data are as follows: 1639 mg/kg (9/10); 1367 mg/kg (8/10); 1183 mg/kg (7/10); and 1001 mg/kg (0/10) for males; and 1365 mg/kg (10/10); 994 mg/kg (8/10); 841 mg/kg (5/10); and 719 mg/kg (2/10) for females. The LD50 was determined to be 1149 mg/kg (males) and 848 mg/kg (females). Clinical signs exhibited within 30-minutes of dosing at all dose levels included tremors, decreased locomotion, chromorhinorrhea, chromodacryorrhea, oral discharge, lacrimation, diarrhea, abdominogenital staining, and ocular opacity. All deaths occurred by day 7 of the study. At gross necropsy, internal lesions were observed which included hemorrhages and thickening of the cardiac portion of the stomach, occult blood in the intestines, and fibrous adhesions within the peritoneal cavity. The test substance was determined to be mildly toxic.[FMC CORP; Initial Submission: Acute Oral Toxicity Study with Methallyl Chloride in Rats with Cover Letter Dated 05/28/92; 12/15/82; EPA Doc. No. 88-920003102; Fiche No. OTS0539687]**UNREVIEWED**
  

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Footnotes

¹ Source: the National Library of Medicine's Hazardous Substance Database, 10/28/2007.