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t-Butylchloride (CASRN 507-20-0)

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0417

t-Butylchloride; CASRN 507-20-0

Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data, as outlined in the IRIS assessment development process. Sections I (Health Hazard Assessments for Noncarcinogenic Effects) and II (Carcinogenicity Assessment for Lifetime Exposure) present the conclusions that were reached during the assessment development process. Supporting information and explanations of the methods used to derive the values given in IRIS are provided in the guidance documents located on the IRIS website.

STATUS OF DATA FOR t-Butylchloride

File First On-Line 04/01/1990

Category (section)
Status
Last Revised
Oral RfD Assessment (I.A.) no data
Inhalation RfC Assessment (I.B.) no data
Carcinogenicity Assessment (II.) on-line 01/01/1991*

*A comprehensive review of toxicological studies was completed (May 22, 2006) - please see section II.D.2. for more information.

_I.  Chronic Health Hazard Assessments for Noncarcinogenic Effects

_I.A. Reference Dose for Chronic Oral Exposure (RfD)

Substance Name — t-Butylchloride
CASRN — 507-20-0

Not available at this time.

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_I.B. Reference Concentration for Chronic Inhalation Exposure (RfC)

Substance Name — t-Butylchloride
CASRN — 507-20-0

Not available at this time.

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_II.  Carcinogenicity Assessment for Lifetime Exposure

Substance Name — t-Butylchloride
CASRN — 507-20-0
Last Revised — 01/01/1991

Section II provides information on three aspects of the carcinogenic assessment for the substance in question; the weight-of-evidence judgment of the likelihood that the substance is a human carcinogen, and quantitative estimates of risk from oral exposure and from inhalation exposure. The quantitative risk estimates are presented in three ways. The slope factor is the result of application of a low-dose extrapolation procedure and is presented as the risk per (mg/kg)/day. The unit risk is the quantitative estimate in terms of either risk per ug/L drinking water or risk per ug/cu.m air breathed. The third form in which risk is presented is a drinking water or air concentration providing cancer risks of 1 in 10,000, 1 in 100,000 or 1 in 1,000,000. The rationale and methods used to develop the carcinogenicity information in IRIS are described in The Risk Assessment Guidelines of 1986 (EPA/600/8-87/045) and in the IRIS Background Document. IRIS summaries developed since the publication of EPA's more recent Proposed Guidelines for Carcinogen Risk Assessment also utilize those Guidelines where indicated (Federal Register 61(79):17960-18011, April 23, 1996). Users are referred to Section I of this IRIS file for information on long-term toxic effects other than carcinogenicity.

_II.A. Evidence for Human Carcinogenicity

__II.A.1. Weight-of-Evidence Characterization

Classification — D; not classifiable as to human carcinogenicity

Basis — Based on no human carcinogenicity data and inadequate animal data.

__II.A.2. Human Carcinogenicity Data

None.

__II.A.3. Animal Carcinogenicity Data

Inadequate. Poirier et al. (1975) gave strain A/Heston mice (10/sex/dose) 3 intraperitoneal injections/ week of 12.9, 32.4, or 65 mmol/kg (1194, 3000, or 6017 mg/kg) t-butylchloride in tricaprylin for 8 weeks. Untreated and tricaprylin-treated mice were used as negative controls, and urethane-treated mice were used as positive controls. The survival of mice in the low-, mid-, and high-dose groups was 40, 55, and 55%, respectively. Survival in the untreated and vehicle controls and the urethane-treated mice was "90%. Remaining animals were sacrificed 24 weeks after the first injection. t- Butylchloride induced a dose-related increase in the number of lung tumors/mouse (0.64+/-0.15, low-dose; 0.73+/-0.22 mid-dose; and 1.00+/-0.27 high-dose) that was statistically significantly elevated at the 32.4 and 65 mmol/kg dose levels relative to untreated (0.21+/-0.03) or vehicle controls (0.36+/-0.14). t-Butylchloride was considered by the authors to be positive for lung tumors in this short-term in vivo screening assay.

__II.A.4. Supporting Data for Carcinogenicity

Simmon (1981) reported that when the cells were exposed to vapors in a dessicator, t-butylchoride (1 uL/desiccator) was mutagenic in Salmonella typhimurium strain TA100 in the absence of hepatic homogenates; however, control data were not provided. Eder et al. (1982) reported that t-butyl- chloride was not mutagenic in S. typhimurium strain TA100 both in the presence and absence of hepatic homogenates.

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_II.B. Quantitative Estimate of Carcinogenic Risk from Oral Exposure

None.

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_II.C. Quantitative Estimate of Carcinogenic Risk from Inhalation Exposure

None.

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_II.D. EPA Documentation, Review, and Contacts (Carcinogenicity Assessment)

__II.D.1. EPA Documentation

Source Document — U.S. EPA, 1988

The 1988 Health and Environmental Effects Document for Monochlorobutanes has received Agency Review.

__II.D.2. EPA Review (Carcinogenicity Assessment)

Agency Work Group Review — 09/07/1989

Verification Date — 09/07/1989

A comprehensive review of toxicological studies published through May 2006 was conducted. No new health effects data were identified that would be directly useful in the revision of the existing carcinogenicity assessment for t-Butylchloride and a change in the assessment is not warranted at this time. For more information, IRIS users may contact the IRIS Hotline at hotline.iris@epa.gov or (202)566-1676.

__II.D.3. EPA Contacts (Carcinogenicity Assessment)

Please contact the IRIS Hotline for all questions concerning this assessment or IRIS, in general, at (202)566-1676 (phone), (202)566-1749 (FAX) or hotline.iris@epa.gov (internet address).

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_III.  [reserved]
_IV.  [reserved]
_V.  [reserved]


_VI.  Bibliography

Substance Name — t-Butylchloride
CASRN — 507-20-0
Last Revised — 04/01/1990

_VI.A. Oral RfD References

None

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_VI.B. Inhalation RfD References

None

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_VI.C. Carcinogenicity Assessment References

Eder, E., D. Henschler and T. Neudecker. 1982. Mutagenic properties of allylic and a,B-unsaturated compounds: Consideration of alkylating mechanisms. Xenobiotica. 12: 831-848.

Poirier, L.A., G.D. Stoner and M.B. Shimkin. 1975. Bioassay of alkyl halides and nucleotide base analogs by pulmonary tumor response in strain A mice. Cancer Res. 35(6): 1411-1415.

Simmon, V.F. 1981. Applications of the Salmonella/microsome assay. In: Short-term Tests Chemical Carcinogens. H. Stich and R. San, Ed. Springer- Verlag, New York. p. 120-126.

U.S. EPA. 1988. Health and Environmental Effects Document for Monochlorobutanes. Prepared by the Office of Health and Environmental Assessment, Environmental Criteria and Assessment Office, Cincinnati, OH for the Office of Solid Waste and Emergency Response, Washington, DC.

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_VII.  Revision History

Substance Name — t-Butylchloride
CASRN — 507-20-0

Date
Section
Description
04/01/1990 II. Carcinogen assessment on-line
04/01/1990 VI. Bibliography on-line
01/01/1991 II. Text edited
01/01/1992 IV. Regulatory Action section on-line
04/01/1997 III., IV., V. Drinking Water Health Advisories, EPA Regulatory Actions, and Supplementary Data were removed from IRIS on or before April 1997. IRIS users were directed to the appropriate EPA Program Offices for this information.
10/28/2003 II.D.2. Screening-Level Literature Review Findings message has been added.
07/05/2006 II.D.2. Screening-Level Literature Review Findings message has been removed and replaced by comprehensive literature review conclusions.

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_VIII.  Synonyms

Substance Name — t-Butylchloride
CASRN — 507-20-0
Last Revised — 04/01/1990

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