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Bayleton
CASRN 43121-43-3
Contents
0131
Bayleton; CASRN 43121-43-3
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 Bayleton
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 -- Bayleton
CASRN -- 43121-43-3
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 weight NOEL: 50 ppm 100 1 3E-2
gain, erythrocyte (2.5 mg/kg/day) mg/kg/day
count and hemoglobin
level LEL: 500 ppm
(25 mg/kg/day)
2-Year Rat Dietary
Study
Mobay Chemical, 1978
*Conversion Factors: 1 ppm = 0.05 mg/kg/day (assumed rat food consumption)
___I.A.2. PRINCIPAL AND SUPPORTING STUDIES (ORAL RfD)
Mobay Chemical Corporation. 1978a. MRID No. 00032538. Available from EPA.
Write to FOI, EPA, Washington, DC 20460.
Fifty male and 50 female young Wistar rats were fed 50, 500, or 5000 ppm of
Bayleton in the diet for 2 years. A control group was included. Animals were
examined daily for physical appearance, body weight, behavioral changes,
clinical effects, and pharmacological response. A decrease in body weight
gain, erythrocyte count, and hemoglobin level was observed at 500 ppm. At
5000 ppm, cyclic decreases in food consumption accompanied by violent motor
reactions were observed. Decreased body weight gain, increased mortality,
decreased hemoglobin, decreased hematocrit and thrombocyte count, and
increased cholesterol were observed at the high dose.
___I.A.3. UNCERTAINTY AND MODIFYING FACTORS (ORAL RfD)
UF -- An uncertainty factor of 100 has been used to account for the inter- and
intraspecies differences in the extrapolation from laboratory animals to
humans.
MF -- None
___I.A.4. ADDITIONAL COMMENTS (ORAL RfD)
Teratogenic studies in rats are positive (cleft palates).
Data Considered for Establishing the RfD:
1) 2-Year Feeding - rat: Principal study - see previous description; core
grade minimum
2) 2-Year Feeding - dog: NOEL=100 ppm (2.5 mg/kg/day); LEL=1000 ppm grade
minimum (25 mg/kg/day) (no weight gain, increased serum alkaline phosphatase
and N-demethylase activity, and increased liver weight); core grade minimum
(Mobay Chemical, 1978b)
3) Teratology - rat: Teratogenic NOEL=50 mg/kg/day; Teratogenic LEL=100
mg/kg/day (cleft palates); Maternal Toxicity NOEL=10 mg/kg/day; Maternal
Toxicity LEL=25 mg/kg/day (increased motor activity and depression of maternal
weight gain); core grade minimum (Mobay Chemical, 1981)
4) Teratology - rabbit: NOEL=50 mg/kg/day (HDT); Maternal Toxicity NOEL=50
mg/kg/day (HDT); core grade minimum (Mobay Chemical, 1976)
5) 3-Generation Reproduction - rat: Fetotoxic NOEL=50 ppm (2.5 mg/kg/day);
LEL=300 ppm (15 mg/kg/day) (decreased pup weight gain); Maternal Toxicity
NOEL=300 ppm; Maternal Toxicity LEL=1800 ppm (90 mg/kg/day) (decreased body
weight gain, effect on lactation performance); Reproductive NOEL=300 ppm;
Reproductive LEL=1800 ppm (decreased fertility, decreased litter size); core
grade minimum (Mobay Chemical, 1979)
Other Data Reviewed:
1) 2-Year Feeding (oncogenic) - mice: Systemic NOEL=50 ppm (7.50 mg/kg/day);
Systemic LEL=300 ppm (45 mg/kg/day) (increased mortality at 12 months); core
grade minimum (Mobay Chemical, 1980)
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 therefore, is given a
high rating. Additional studies are of medium to high quality. Moreover, the
2-year dog study provides the same NOEL and RfD. Therefore, 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
Office of Pesticide Programs Files
Agency Work Group Review -- 03/11/1986
Verification Date -- 03/11/1986
___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 -- Bayleton
CASRN -- 43121-43-3
Not available at this time.
_II. CARCINOGENICITY ASSESSMENT FOR LIFETIME EXPOSURE
Substance Name -- Bayleton
CASRN -- 43121-43-3
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 -- Bayleton
CASRN -- 43121-43-3
Last Revised -- 11/01/1989
__VI.A. ORAL RfD REFERENCES
Mobay Chemical Corporation. 1976. MRID No. 00048631, 00060230. Available
from EPA. Write to FOI, EPA, Washington, DC 20460.
Mobay Chemical Corporation. 1978a. MRID No. 00032538. Available from EPA.
Write to FOI, EPA, Washington, DC 20460.
Mobay Chemical Corporation. 1978b. MRID No. 00032539. Available from EPA.
Write to FOI, EPA, Washington, DC 20460.
Mobay Chemical Corporation. 1979. MRID No. 00032541. Available from EPA.
Write to FOI, EPA, Washington, DC 20460.
Mobay Chemical Corporation. 1980. MRID No. 00069013. Available from EPA.
Write to FOI, EPA, Washington, DC 20460.
Mobay Chemical Corporation. 1981. MRID No. 00089023. 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 -- Bayleton
CASRN -- 43121-43-3
-------- -------- --------------------------------------------------------
Date Section Description
-------- -------- --------------------------------------------------------
03/01/1988 I.A.1. Dose conversion clarified
03/01/1988 I.A.4. Core grades added
11/01/1989 VI. Bibliography on-line
01/01/1992 IV. Regulatory action on-line
VIII. SYNONYMS
Substance Name -- Bayleton
CASRN -- 43121-43-3
Last Revised -- 03/31/1987
43121-43-3
AMIRAL
BAY 6681 F
Bayleton
BAY-MEB-6447
2-BUTANONE, 1-(4-CHLOROPHENOXY)-3,3-DIMETHYL-1-(1,2,4-TRIAZOL-1-YL)-
1-(4-CHLOROPHENOXY)-3,3-DIMETHYL-1-(1,2,4-TRIAZOL-1-YL)-BUTAN-2-ONE
1-(4-CHLOROPHENOXY)-3,3-DIMETHYL-1-(1H-1,2,4-TRIAZOL-1-YL)-2-BUTANONE
MEB 6447
TRIADIMEFON
1H-1,2,4-TRIAZOLE, 1-((tert-BUTYLCARBONYL-4-CHLOROPHENOXY)METHYL)-
Last updated: 5 May 1998
URL: http://www.epa.gov/iris/SUBST/0131.HTM
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