|
Baythroid
CASRN 68359-37-5
Contents
0132
Baythroid; CASRN 68359-37-5
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 Baythroid
File On-Line 03/31/1987
Category (section) Status Last Revised
----------------------------------------- -------- ------------
Oral RfD Assessment (I.A.) on-line 03/01/1988
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 -- Baythroid
CASRN -- 68359-37-5
Last Revised -- 03/01/1988
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 body NOEL: 50 ppm 100 1 2.5E-2
weights in males, (2.5 mg/kg/day) mg/kg/day
inflammatory foci in
kidneys of females LEL: 150 ppm
(7.5 mg/kg/day)
2-Year Rat Study,
Dietary
Mobay Chemical, 1983a
*Conversion Factors: l ppm = 0.05 mg/kg/day (assumed rat food consumption)
___I.A.2. PRINCIPAL AND SUPPORTING STUDIES (ORAL RfD)
Mobay Chemical Corporation. 1983a. MRID No. 00137303. Available from EPA.
Write to FOI, EPA, Washington, DC 20460.
Sixty-five male and 65 female Wistar SPF rats, 5-6 weeks of age, were
assigned to four groups which were fed diets containing 0, 50, 150, and 450
ppm of baythroid. Animals were observed for clinical signs twice daily and
once daily on weekends and holidays. Individual body weights and group food
consumption were determined weekly for the first 26 weeks, biweekly during
week 27 through 74, and then weekly until termination. Hematology, clinical
chemistry, and urinalysis were performed on 10 rats/sex/group at 6, 12, 18,
and 24 months of study. Observed results included decreased body weights in
males and inflammatory foci in kidneys of females.
___I.A.3. UNCERTAINTY AND MODIFYING FACTORS (ORAL RfD)
UF -- A 100-fold UF has been used to compensate for both the interspecies
differences in extrapolating from the human, and the expected intrahuman
variability to the toxicity of this chemical.
MF -- None
___I.A.4. ADDITIONAL COMMENTS (ORAL RfD)
Data Considered for Establishing the RfD:
1) 2-Year Feeding - rat: Principal study - see previous description; core
grade minimum
2) 1-Year Feeding - dog: NOEL=160 ppm (4 mg/kg/day); LEL=640 ppm (16
mg/kg/day) (slight ataxia in two dogs, one occasion each; increased vomiting;
increased pasty-to-liquid feces; decreased body weights in males); core grade
minimum (Mobay Chemical, 1983b)
3) 3-Generation Reproduction - rat: Systemic NOEL=50 ppm (2.5 mg/kg/day);
Systemic LEL=150 ppm (7.5 mg/kg/day) (body weight decrease in the pups);
Reproductive NOEL=50 ppm; Reproductive LEL=150 ppm (decreased viability
index); core grade minimum (Mobay Chemical, 1983c)
4) Teratology - rat: Maternal NOEL=3 mg/kg/day; Maternal LEL=10\mg/kg/day
(behavioral changes in gait and coordination); Teratogenic NOEL=30 mg/kg/day
(HDT); Fetotoxic NOEL=30 mg/kg/day (HDT); core grade minimum (Mobay Chemical,
1982)
5) Teratology - rabbit: Maternal NOEL=15 mg/kg/day, Maternal LEL=45\mg/kg/day
(abortion and resorption); Teratogenic NOEL=45 mg/kg/day (HDT); Fetotoxic
NOEL=45 mg/kg/day (HDT); core grade minimum (Mobay Chemical, 1983d)
Other Data Reviewed:
1) 23-Month Feeding (oncogenic) - mice: Systemic NOEL=none; Systemic LEL=50
ppm (7.5 mg/kg/day) (LDT) (increased alkaline phosphatase activity in males);
core grade supplementary (Mobay Chemical, 1983e)
Data Gap(s): None
___I.A.5. CONFIDENCE IN THE ORAL RfD
Study -- High
Data Base -- High
RfD -- High
The principal study appears to be of good quality and is given a high rating.
Since there are no data gaps existing for baythroid and additional studies are
also of good quality, the data base is given a high confidence. High
confidence in the RfD follows.
___I.A.6. EPA DOCUMENTATION AND REVIEW OF THE ORAL RfD
Pesticide Registration Files
Agency Work Group Review -- 04/08/1986
Verification Date -- 04/08/1986
___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 -- Baythroid
CASRN -- 68359-37-5
Not available at this time.
_II. CARCINOGENICITY ASSESSMENT FOR LIFETIME EXPOSURE
Substance Name -- Baythroid
CASRN -- 68359-37-5
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 -- Baythroid
CASRN -- 68359-37-5
Last Revised -- 11/01/1989
__VI.A. ORAL RfD REFERENCES
Mobay Chemical Corporation. 1982. MRID No. 00131533. Available from EPA.
Write to FOI, EPA, Washington, DC 20460.
Mobay Chemical Corporation. 1983a. MRID No. 00137303. Available from EPA.
Write to FOI, EPA, Washington, DC 20460.
Mobay Chemical Corporation. 1983b. MRID No. 00151358. Available from EPA.
Write to FOI, EPA, Washington, DC 20460.
Mobay Chemical Corporation. 1983c. MRID No. 00131532, 00137545, 00149597.
Available from EPA. Write to FOI, EPA, Washington, DC 20460.
Mobay Chemical Corporation. 1983d. MRID No. 00131534. Available from EPA.
Write to FOI, EPA, Washington, DC 20460.
Mobay Chemical Corporation. 1983e. MRID No. 00137304. Available from EPA.
Write to FOI, EPA, Washington, DC 20460.
__VI.B. INHALATION RfD REFERENCES
None
__VI.C. CARCINOGENICITY ASSESSMENT REFERENCES
None
_VII. REVISION HISTORY
Substance Name -- Baythroid
CASRN -- 68359-37-5
-------- -------- --------------------------------------------------------
Date Section Description
-------- -------- --------------------------------------------------------
11/01/1989 VI. Bibliography on-line
VIII. SYNONYMS
Substance Name -- Baythroid
CASRN -- 68359-37-5
Last Revised -- 03/31/1987
68359-37-5
BAY FCR 1272
Baythroid
BAYTHROID H
CYFLUTHRIN
Last updated: 5 May 1998
URL: http://www.epa.gov/iris/SUBST/0132.HTM
|
