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Bidrin (CASRN 141-66-2)

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0211

Bidrin; CASRN 141-66-2

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 Bidrin

File First On-Line 09/30/1987

Category (section)
Status
Last Revised
Oral RfD Assessment (I.A.) on-line 11/01/1989
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 — Bidrin
CASRN — 141-66-2
Last Revised — 11/01/1989

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

Decreased pup
survival

3-Generation Rat
Reproduction Study

Shell Chemical, 1965a

NOEL: 2 ppm diet
(0.1 mg/kg/day)

LEL: 5 ppm diet
(0.25 mg/kg/day)

1000
1
1E-4
mg/kg/day

*Conversion Factors -- 1 ppm = 0.05 mg/kg/day (assumed rat food consumption)

__I.A.2. Principal and Supporting Studies (Oral RfD)

Shell Chemical Company. 1965a. MRID No. 00013446, 00066340. Available from EPA. Write to FOI, EPA, Washington, DC 20460.

Bidrin was dissolved in water and mixed with powdered rat food to produce concentrations of 2, 5, 15, and 50 ppm. The study was conducted in two parts. In part one, weanling Long-Evans rats were assigned (10 males and 20 females) to groups receiving 0, 5, 15, or 50 ppm bidrin. In part two, weanling Long- Evans rats were assigned (10 males and 20 females) to groups receiving 0 and 2 ppm bidrin. Sections of brain, heart, lung, liver, spleen, pancreas, kidney, and testes were preserved for histologic examination. Reproductive toxicity (decreased pup survival) was observed at 5 ppm. Other effects (weakness, emaciation, and CNS effects) were seen at 50 ppm. No effects were observed at 2 ppm.

__I.A.3. Uncertainty and Modifying Factors (Oral RfD)

UF — An uncertainty factor of 1000 was used to account for the inter- and intraspecies differences, and to account for the fact that the chronic toxicity database is incomplete.

MF — None

__I.A.4. Additional Studies/Comments (Oral RfD)

Data Considered for Establishing the RfD:

1) 3-Generation Reproduction - rat: Principal study - see previous description; core grade supplementary

2) 2-Year Feeding (oncogenic) - rat: ChE NOEL=none; ChE LEL=0.05 mg/kg/day (plasma ChE inhibition); core grade supplementary; interim report (Shell Chemical, 1967a)

3) 2-Year Feeding - dog ChE NOEL=0.04 mg/kg/day; ChE LEL=0.4 mg/kg/day (RCB and plasma ChE inhibition); core grade supplementary; interim report (Shell Chemical, 1967b)

4) Teratology - rat: Embryotoxic NOEL=2.5 mg/kg/day; Embryotoxic LEL=5 mg/kg/day (decreased implantation sites); core grade supplementary; preliminary report (Shell Chemical, 1965b)

5) Teratology - rabbit: Maternal NOEL=4 mg/kg/day; Maternal LEL=8 mg/kg/day (salivation and tremors); no core grade (Shell Chemical, 1973)

Data Gap(s): Chronic Rat Feeding Study; Chronic Dog Feeding Study; Rat Reproduction Study; Rat Teratology Study; Rabbit Teratology Study

__I.A.5. Confidence in the Oral RfD

Study — Low
Database — Low
RfD — Low

The principal study is of low quality and is given a low confidence rating. Additional studies are also of low quality and, therefore, the database is given a low confidence rating. Low confidence in the RfD follows.

__I.A.6. EPA Documentation and Review of the Oral RfD

Pesticide Data Evaluation Record and Registration Standard

Agency Work Group Review — 08/19/1986, 09/02/1986

Verification Date — 08/19/1986

Screening-Level Literature Review Findings — A screening-level review conducted by an EPA contractor of the more recent toxicology literature pertinent to the RfD for Bidrin conducted in September 2002 identified one or more significant new studies. IRIS users may request the references for those studies from 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).

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

Substance Name — Bidrin
CASRN — 141-66-2

Not available at this time.


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_II.  Carcinogenicity Assessment for Lifetime Exposure

Substance Name — Bidrin
CASRN — 141-66-2

This substance/agent has not undergone a complete evaluation and determination under US EPA's IRIS program for evidence of human carcinogenic potential.

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


_VI.  Bibliography

Substance Name — Bidrin
CASRN — 141-66-2
Last Revised — 11/01/1989

_VI.A. Oral RfD References

Shell Chemical Company. 1965a. MRID No. 00013446, 00066340. Available from EPA. Write to FOI, EPA, Washington, DC 20460.

Shell Chemical Company. 1965b. MRID No. 00013447, 00141908. Available from EPA. Write to FOI, EPA, Washington, DC 20460.

Shell Chemical Company. 1967a. MRID No. 00013563, 00013966. Available from EPA. Write to FOI, EPA, Washington, DC 20460.

Shell Chemical Company. 1967b. MRID No. 00013564, 00013966. Available from EPA. Write to FOI, EPA, Washington, DC 20460.

Shell Chemical Company. 1973. Accession No. 111367. Available from EPA. Write to FOI, EPA, Washington, DC 20460.

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_VI.B. Inhalation RfC References

None

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_VI.C. Carcinogenicity Assessment References

None

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_VII.  Revision History

Substance Name — Bidrin
CASRN — 141-66-2

Date
Section
Description
11/01/1989 I.A. Principal study year corrected
11/01/1989 VI. Bibliography on-line
01/01/1992 IV. Regulatory actions updated
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.

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_VIII.  Synonyms

Substance Name — Bidrin
CASRN — 141-66-2
Last Revised — 09/30/1987

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