Jump to main content.

beta-Chloronaphthalene (CASRN 91-58-7)

List of IRIS Substances

view QuickView

Main Contents



beta-Chloronaphthalene; CASRN 91-58-7

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 beta-Chloronaphthalene

File First On-Line 11/01/1990

Category (section)
Last Revised
Oral RfD Assessment (I.A.) on-line 11/01/1990*
Inhalation RfC Assessment (I.B.) no data  
Carcinogenicity Assessment (II.) no data  

*A comprehensive review of toxicological studies was completed 01/06/05 - please see section I.A.6 for more information.

_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*

Dyspnea, abnormal
appearance, liver

Mouse Subchronic Oral
Gavage Study

U.S. EPA, 1989

NOAEL: 250 mg/kg/day

LOAEL: 600 mg/kg/day

8E-2 mg/kg/day  

*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 Studies/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
Database — 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

A comprehensive review of toxicological studies published through 2004 was conducted. No new health effects data were identified that would be directly useful in the revision of the existing RfD for beta-Chloronaphthalene and a change in the RfD 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.

__I.A.7. EPA Contacts (Oral RfD)

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).

Top of page

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

Substance Name — beta-Chloronaphthalene
CASRN — 91-58-7

Not available at this time.

Top of page

_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.

Top of page

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

_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.

Top of page

_VI.B. Inhalation RfC References


Top of page

_VI.C. Carcinogenicity Assessment References


Top of page

_VII.  Revision History

Substance Name — beta-Chloronaphthalene
CASRN — 91-58-7

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
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.
12/03/2002 I.A.6. Screening-Level Literature Review Findings message has been added.
03/03/2005 I.A.6. Screening-Level Literature Review Findings message has been removed and replaced by comprehensive literature review conclusions.

Top of page

_VIII.  Synonyms

Substance Name — beta-Chloronaphthalene
CASRN — 91-58-7
Last Revised — 11/01/1990

Top of page

Recent Additions | Search IRIS | IRIS Home | NCEA Home | ORD Home

Jump to main content.