|
Bromochloromethane
CASRN 74-97-5
Contents
0532
Bromochloromethane; CASRN 74-97-5
Health assessment information on a chemical substance is included in IRIS only
after a comprehensive review of chronic toxicity data by U.S. EPA health
scientists from several Program Offices and the Office of Research and
Development. The summaries presented in Sections I and II represent a
consensus reached in the review process. Background information and
explanations of the methods used to derive the values given in IRIS are
provided in the Background Documents.
STATUS OF DATA FOR Bromochloromethane
File On-Line 03/01/1991
Category (section) Status Last Revised
----------------------------------------- -------- ------------
Oral RfD Assessment (I.A.) no data
Inhalation RfC Assessment (I.B.) no data
Carcinogenicity Assessment (II.) on-line 03/01/1991
_I. CHRONIC HEALTH HAZARD ASSESSMENTS FOR NONCARCINOGENIC EFFECTS
__I.A. REFERENCE DOSE FOR CHRONIC ORAL EXPOSURE (RfD)
Substance Name -- Bromochloromethane
CASRN -- 74-97-5
Not available at this time.
__I.B. REFERENCE CONCENTRATION FOR CHRONIC INHALATION EXPOSURE (RfC)
Substance Name -- Bromochloromethane
CASRN -- 74-97-5
Not available at this time.
_II. CARCINOGENICITY ASSESSMENT FOR LIFETIME EXPOSURE
Substance Name -- Bromochloromethane
CASRN -- 74-97-5
Last Revised -- 03/01/1991
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 CLASSIFICATION AS TO HUMAN CARCINOGENICITY
___II.A.1. WEIGHT-OF-EVIDENCE CLASSIFICATION
Classification -- D; not classifiable as to human carcinogenicity.
Basis -- Based on the lack of data regarding the carcinogenicity of
bromochloromethane in humans or animals; however, there are data indicative
of genotoxic effects and structural relationships to halogenated methanes
classified as B2 probable human carcinogens.
___II.A.2. HUMAN CARCINOGENICITY DATA
None.
___II.A.3. ANIMAL CARCINOGENICITY DATA
None.
___II.A.4. SUPPORTING DATA FOR CARCINOGENICITY
Mutagenicity tests with bromochloromethane in microorganisms yielded
consistently positive results. Osterman-Golkar et al. (1983) reported
positive responses in reverse mutation assays with Salmonella typhimurium
TA100 and TA1535 exposed to bromochloromethane in the absence of activation at
20-60 mM and with or without activation in the vapor phase at 10 uL/plate.
Similarly, Simmon (1978), Simmon et al. (1977), and Simmon and Tardiff (1978)
reported positive results in S. typhimurium exposed without activation at 10-
50 uL/dessicator. Reverse mutations were observed at the tyr locus in
Escherichia coli WU361089 exposed at 10 uL/plate without activation (Osterman-
Golkar et al., 1983). Prophage induction was also observed in E. coli K394
exposed without activation at 10 uL/plate (Osterman-Golkar et al., 1983).
Bromochloromethane is structurally similar to dichloromethane (methylene
chloride) which is classified B2, probable human carcinogen.
__II.B. QUANTITATIVE ESTIMATE OF CARCINOGENIC RISK FROM ORAL EXPOSURE
None.
__II.C. QUANTITATIVE ESTIMATE OF CARCINOGENIC RISK FROM INHALATION EXPOSURE
None.
__II.D. EPA DOCUMENTATION, REVIEW, AND CONTACTS (CARCINOGENICITY ASSESSMENT)
___II.D.1. EPA DOCUMENTATION
Source Document -- U.S. EPA, 1990
The Health and Environmental Effects Document for Bromochloromethane will be
subjected to external peer review and Agency review.
___II.D.2. REVIEW (CARCINOGENICITY ASSESSMENT)
Agency Work Group Review -- 01/10/1991
Verification Date -- 01/10/1991
___II.D.3. U.S. EPA CONTACTS (CARCINOGENICITY ASSESSMENT)
Please contact the Risk Information Hotline for all questions concerning this
assessment or IRIS, in general, at (513)569-7254 (phone), (513)569-7159 (FAX)
or RIH.IRIS@EPAMAIL.EPA.GOV (internet address).
_VI. BIBLIOGRAPHY
Substance Name -- Bromochloromethane
CASRN -- 74-97-5
Last Revised -- 03/01/1991
__VI.A. ORAL RfD REFERENCES
None
__VI.B. INHALATION RfC REFERENCES
None
__VI.C. CARCINOGENICITY ASSESSMENT REFERENCES
Osterman-Golkar, S., S. Hussain, S. Walles, B. Anderstam and K. Sigvardsson.
1983. Chemical reactivity and mutagenicity of some dihalomethanes. Chem.-
Biol. Interact. 46(1): 121-130.
Simmon, V.F. 1978. Structural correlations of carcinogenic and mutagenic
alkyl halides. U.S. DHEW Publ. FDA 78-1045. Struct. Correl. Carcinog.
Mutagen. p. 163-171.
Simmon, V.F. and R.G. Tardiff. 1978. Mutagenic activity of halogenated
compounds found in chlorinated drinking water. Water Chlorination: Environ.
Health Eff. Proc. Conf. 2: 417-431.
Simmon, V.F., K. Kauhanen and R.G. Tardiff. 1977. Mutagenic activity of
chemicals identified in drinking water. Dev. Toxicol. Environ. Sci. 2(Prog.
Genet. Toxicol.): 249-258.
U.S. EPA. 1990. Health and Environmental Effects Document for
Bromochloromethane. Prepared by the Environmental Criteria and Assessment
Office, Cincinnati, OH for the Office of Solid Waste and Emergency Response,
Washington, DC.
_VII. REVISION HISTORY
Substance Name -- Bromochloromethane
CASRN -- 74-97-5
-------- -------- --------------------------------------------------------
Date Section Description
-------- -------- --------------------------------------------------------
03/01/1991 II. Carcinogenicity assessment on-line
03/01/1991 VI. Bibliography on-line
01/01/1992 IV. Regulatory Action section on-line
VIII. SYNONYMS
Substance Name -- Bromochloromethane
CASRN -- 74-97-5
Last Revised -- 03/01/1991
74-97-5
Methane, bromochloro-
Bromochloromethane
Bromoclorometano [Spanish]
Chlorobromomethane
Fluorocarbon 1011
Halon 1011
HSDB 2520
METHANE, BROMOCHLORO-
Methylene chlorobromide
MIL-B-4394-B
MONO-CHLORO-MONO-BROMO-METHANE
Monochloromonobromomethane
NSC 7294
UN 1887
Last updated: 5 May 1998
URL: http://www.epa.gov/iris/SUBST/0532.HTM
|
