|
beta-Chloronaphthalene
CASRN 91-58-7
Contents
0463
beta-Chloronaphthalene; CASRN 91-58-7
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 beta-Chloronaphthalene
File On-Line 11/01/1990
Category (section) Status Last Revised
----------------------------------------- -------- ------------
Oral RfD Assessment (I.A.) on-line 11/01/1990
Inhalation RfC Assessment (I.B.) no data
Carcinogenicity Assessment (II.) no data
_I. CHRONIC HEALTH HAZARD ASSESSMENTS FOR NONCARCINOGENIC EFFECTS
__I.A. REFERENCE DOSE FOR CHRONIC ORAL EXPOSURE (RfD)
Substance Name -- beta-Chloronaphthalene
CASRN -- 91-58-7
Last Revised -- 11/01/1990
The oral Reference Dose (RfD) is based on the assumption that thresholds exist
for certain toxic effects such as cellular necrosis. It is expressed in units
of mg/kg-day. In general, the RfD is an estimate (with uncertainty spanning
perhaps an order of magnitude) of a daily exposure to the human population
(including sensitive subgroups) that is likely to be without an appreciable
risk of deleterious effects during a lifetime. Please refer to the Background
Document for an elaboration of these concepts. RfDs can also be derived for
the noncarcinogenic health effects of substances that are also carcinogens.
Therefore, it is essential to refer to other sources of information concerning
the carcinogenicity of this substance. If the U.S. EPA has evaluated this
substance for potential human carcinogenicity, a summary of that evaluation
will be contained in Section II of this file.
___I.A.1. ORAL RfD SUMMARY
Critical Effect Experimental Doses* UF MF RfD
-------------------- ----------------------- ----- --- ----------
Dyspnea, abnormal NOAEL: 250 mg/kg/day 3000 1 8E-2
appearance, liver mg/kg/day
enlargement LOAEL: 600 mg/kg/day
Mouse Subchronic Oral
Gavage Study
U.S. EPA, 1989
*Conversion Factors: None
___I.A.2. PRINCIPAL AND SUPPORTING STUDIES (ORAL RfD)
U.S. EPA. 1989. Subchronic study in mice with beta-Chloronaphthalene. HLA
Study No. 2399-124. Prepared by Hazleton Laboratories America, Inc. for the
U.S. EPA, Office of Solid Waste, Washington DC.
CD-1 mice (20/sex/group) were administered oral gavage dosages of 0, 100, 250,
or 600 mg/kg/day beta-chloronaphthalene in corn oil for 13 weeks. Parameters
examined included mortality, body and organ weight changes, food consumption,
clinical signs, opthalmologic changes, hematology, clinical chemistry, and
gross histopathology. Mortality was reported in one male and one female low-
dose mice and in three male and two female high-dose mice, although no
statistical significance was found when compared with controls. Daily
observations revealed dyspnea, rough hair coat, and languid, thin, hunched
appearance of high-dose animals; these signs were more prevalent among females
than males. Similar symptoms were also observed in other treatment groups,
but the incidence was not statistically significant. Although total food
consumption was significantly increased in high-dose males throughout the
study, this did not result in a significant increase in body weight gain,
compared with controls. Absolute and relative liver and gall bladder weights
were significantly increased in both sexes at the high-dose level and were
accompanied by centrilobular hepatocellular enlargement. Both absolute and
relative adrenal weights were significantly increased in low-dose females, but
no dose-response relationship could be established, nor was there any
corresponding histopathologic changes. No other effects were observed. The
LOAEL was identified as 600 mg/kg/day and the NOAEL was 250 mg/kg/day.
___I.A.3. UNCERTAINTY AND MODIFYING FACTORS (ORAL RfD)
UF -- An uncertainty factor of 3000 reflects 10 each for inter- and
intraspecies conversion, 10 for the use of a subchronic study for chronic RfD
derivation, and 3 to account for the lack of reproductive/developmental and
chronic toxicity data.
MF -- None
___I.A.4. ADDITIONAL COMMENTS (ORAL RfD)
Brodie et al. (1971) injected male Sprague-Dawley rats i.p. with 80 mg
phenobarbital/kg bw for three successive days, followed by a similar injection
of beta-chloronaphthalene the next day. Livers were removed 24 hours after
the injection and examined; extensive necrosis was found. In this study,
which was designed to investigate the hepatotoxicity of halogenated aromatic
hydrocarbons using a variety of compounds, the authors concluded that the
liver can convert stable organic compounds to alkylating agents that form
covalent bonds with tissue macromolecules. The study is inadequate for oral
RfD derivation due to the inappropriate route of administration, duration of
exposure, and dependence on phenobarbital for the obtained result.
___I.A.5. CONFIDENCE IN THE ORAL RfD
Study -- Medium
Data Base -- Low
RfD -- Low
Confidence in the principal study is medium: it is a well-designed study that
examined and identified both a LOAEL and NOAEL for multiple endpoints using an
adequate number of animals. Clinical signs reported at the LOAEL provide
additional strength; the liver effects seen at the LOAEL are also supported by
the liver toxicity observed by Brodie et al. (1971). Confidence in the data
base is low; developmental, reproductive and chronic toxicity following oral
exposure to beta-chloronaphthalene have not been tested. Confidence in the
RfD is accordingly low.
___I.A.6. EPA DOCUMENTATION AND REVIEW OF THE ORAL RfD
Source Document -- This assessment is not presented in any existing U.S. EPA
document.
Other EPA Documentation -- None
Agency Work Group Review -- 02/21/1990
Verification Date -- 02/21/1990
___I.A.7. EPA CONTACTS (ORAL RfD)
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).
__I.B. REFERENCE CONCENTRATION FOR CHRONIC INHALATION EXPOSURE (RfC)
Substance Name -- beta-Chloronaphthalene
CASRN -- 91-58-7
Not available at this time.
_II. CARCINOGENICITY ASSESSMENT FOR LIFETIME EXPOSURE
Substance Name -- beta-Chloronaphthalene
CASRN -- 91-58-7
This substance/agent has not undergone a complete evaluation and determination
under US EPA's IRIS program for evidence of human carcinogenic potential.
_VI. BIBLIOGRAPHY
Substance Name -- beta-Chloronaphthalene
CASRN -- 91-58-7
Last Revised -- 11/01/1990
__VI.A. ORAL RfD REFERENCES
Brodie, B.B., W.D. Reid, A.K. Cho, G. Sipes, G. Krishna and J.R. Gillette.
1971. Possible mechanisms of liver necrosis caused by aromatic organic
compounds. Proc. Natl. Acad. Sci. 68: 160-164.
U.S. EPA. 1989. Subchronic study in mice with beta-Chloronaphthalene. HLA
Study No. 2399-124. Prepared by Hazleton Laboratories America, Inc. for U.S.
EPA, Office of Solid Waste, Washington, DC.
__VI.B. INHALATION RfC REFERENCES
None
__VI.C. CARCINOGENICITY ASSESSMENT REFERENCES
None
_VII. REVISION HISTORY
Substance Name -- beta-Chloronaphthalene
CASRN -- 91-58-7
-------- -------- --------------------------------------------------------
Date Section Description
-------- -------- --------------------------------------------------------
11/01/1990 I.A. Oral RfD summary on-line
11/01/1990 VI. Bibliography on-line
01/01/1992 IV. Regulatory Action section on-line
VIII. SYNONYMS
Substance Name -- beta-Chloronaphthalene
CASRN -- 91-58-7
Last Revised -- 11/01/1990
91-58-7
Naphthalene, 2-chloro-
beta-CHLORONAPHTHALENE
HSDB 4014
RCRA WASTE NUMBER U047
2-CHLORNAFTALEN [Czech]
2-CHLORONAPHTHALENE
Last updated: 5 May 1998
URL: http://www.epa.gov/iris/SUBST/0463.HTM
|
