Butafenacil
CAS No. 134605-64-4
US Federal Register
 
 

Return to Index Page

CTIVITY: Herbicide (uracil)

CAS Name: 2-[4-fluoro-3-(trifluoromethyl)phenoxy]-N-(phenylmethyl)butanamide

Structure:

US Federal Register

Published Date Docket Identification Number Details
November 8, 2006 EPA-HQ-OPP-2006-0084

Notice of Receipt of Requests to Voluntarily Cancel Certain Pesticide Registrations.

EPA Registration Number Product Name Registrant
000100-01136 Butafenacil Technical Syngenta Crop Protection, Inc.,
Attn: Regulatory Affairs, Po
Box 18300,
Greensboro NC 27419-8300
000100-01137 Inspire EC
Sept 19, 2003 OPP-2003-0282

Pesticide tolerance. FINAL RULE. Tolerances are established for residues of the herbicide butafenacil in or on the following

Agricultural commodities:  Parts per million
Cotton, gin byproducts 10
Cotton, undelinted seed 0.50
Livestock commodities:
also includes tolerances for the residues of the
metabolite, or dimer of butafenacil, CGA-293731 (1-carboxy-1-methylethyl 2- chloro-5-[3,6-dihydro-3-methyl-2,6-dioxo-4-(trifluoromethyl)-1(2H)- pyrimidinyl] benzoate)
Kidney: Cattle, Goats, Hog, Horse, Sheep 0.05
Liver: Cattle, Goats, Hog, Horse, Sheep 0.50

-- food and feed uses. No tolerances have previously been established for butafenacil.
-- Cancer. Butafenacil showed no evidence of carcinogenicity in animal tests in two different species, and therefore, a quantitative cancer risk assessment was not performed.
-- There are currently no registered residential uses of butafenacil.
-- Conditions: As a condition of registration, the petitioner must submit:
1. A ruminant liver and kidney enforcement method and submit adequate validation, ILV, and radiovalidation data.
2. Submit confirmatory data on the frozen storage stability of residues of butafenacil in or on cottonseed, cotton gin byproduct, cotton hull, cotton meal, and cotton oil.
3. Submit a ruminant feeding study to confirm the Agency's estimate of maximum residues of butafenacil from the goat metabolism study.

Some excerpts from Table 2.--Subchronic, Chronic, and Other Toxicity
Study type
[Guideline number]
Results
90-Day oral (dietary) toxicity rodents
(rat) - [870.3100]
NOAEL = 300 ppm (18.8/20.6 mg/kg/ day M/F). LOAEL = 1,000 ppm (62.3/69.3 mg/kg/ day M/F) based on decreased body weight gains, decreased hemoglobin, hematocrit, mean corpuscular hemoglobin (MCH), mean corpuscular volume (MCV), increased red cell volume, increased bone marrow hypercellularity; increased bilirubin and urobilinogen; increased alanine aminotransferase; hepatocyte necrosis; inflammatory liver cell infiltration
90-Day oral (dietary) toxicity in rodents (mouse) - [870.3100] NOAEL = 30 ppm (4.11/5.67 mg/kg/day M/F) LOAEL = 100 ppm (13.8/20.1 mg/kg/ day M/F), based on hepatic histopathology: fatty change, glycogen deposition, and hypertrophy in both sexes
90-Day oral (capsule) toxicity in non- rodents (dog) - [870.3150] NOAEL = 200 mg/kg/ day M/F LOAEL = 1,000 mg/kg/ day M/F, based on decreases in MCV and MCH in males; increases in RDW, HDW, platelets and triglycerides in males; and hemosiderosis in spleen and liver and extramedullary hematopoiesis the spleen in males
2-Generation reproduction and fertility effects - [870.3800] Parental/systemic NOAEL = 30 ppm (2.4/ 2.5 mg/kg/day M/F) Parental/systemic LOAEL = 300 ppm (23.8/25.2 mg/kg/ day M/F), based on decreased body weights and food consumption and on increased incidences of bile duct hyperplasia and liver necrosis in males and females of both generations Offspring NOAEL = 300 ppm (23.8/25.2 mg/kg/day M/F) Offspring LOAEL = 1,000 ppm (79.6/ 83.8 M/F), based on decreased pup body weight and body weight gain in both generations Reproductive NOAEL = 30 ppm (2.4/2.5 mg/ kg/day M/F) Reproductive LOAEL = 300 ppm (23.8/25.2 mg/kg/day M/F) based on an increase in the number of days to mating in both generations
1-Year chronic oral (capsule) toxicity
(dog) - [870.4100]
NOAEL = 500 mg/kg/day M/F LOAEL = 1,000 mg/kg/ day M/F, based on decreased body weight gain in males, decreased MCV, MCH, and mean corpuscular hemoglobin concentration (MCHC); increased thrombocytes and red cell volume distribution width; hepatic histopathology: glycogen disposition, inclusion bodies in cytoplasm, and pigment disposition in both sexes, and focal vaculolation [liver] in females
18-Month carcinogenicity dietary study
(mouse) - [870.4200]
NOAEL = 10 ppm (1.17/1.20 mg/kg/day M/F) LOAEL = 60 ppm (6.96/ 6.59 mg/kg/day M/ F), based on enlarged livers with increased weights, and hepatic microscopic lesions including Kupffer cell hyperplasia, inflammatory cell infiltration, and single cell necrosis in both sexes and on deposits of lipofuscin in males No evidence of carcinogenicity
Combined 2-Year chronic/ carcinogenicity dietary study
(rat) - [870.4300]
NOAEL = 100 ppm (3.76/4.43 mg/kg/ day M/F) LOAEL = 300 ppm (11.4/13.0 mg/kg/ day M/F), based on minimal hepatic abnormalities in the females, including a fatty change and increased mitotic activity No evidence of carcinogenicity
In vitro mammalian cells in culture - [870.5300] Evidence of borderline induction of mutant colonies in presence of S9 in a mammalian cell gene mutation assay at the hypoxanthine guanine phophoribosyl transferase (HGPRT) locus of Chinese hamster V79 cells
Mechanistic studies - [870.7485] Effects on enzymes of cultured mouse, rat, and/or human hepatocytes involved with heme biosynthesis
Mechanistic studies - [870.7485] Effects on liver microsomal and plasma protox activity and its metabolic conversion
Mechanistic studies - [870.7485] Effects on porphyrin profile in rats; treatment induced porphyria, consisting of accumulation of selected porphyrins in the liver, spleen, and plasma and increased excretion in urine and feces
Mechanistic studies - [870.7485] Test substance interferes with heme biosynthesis in rats, as evidenced by dose- dependent, pronounced porphyria in the liver, spleen, and plasma; increased porphyrin excretion, and decreased activity of various isoenzymes of the hepatic microsomal cytochrome P450 system
Some excerpts from Table 3.--Toxicological Dose and Endpoints for Butafenacil
- a summary of the toxicological endpoints used for human risk assessment
-- Exposure Scenario
-- Dose Used in Risk Assessment, UF
-- Special FQPA SF* and Level of Concern for Risk Assessment
Study and Toxicological Effects
-- Chronic dietary (All populations)
-- NOAEL= 1.2 mg/kg/day UF = 100
-- Chronic RfD = 0.012 mg/ kg/day.

-- Special FQPA SF = 1 cPAD = chronic RfD
-- Special FQPA SF = 0.012 mg/kg/day.
Mouse oncogenicity study.
The LOAEL is 6.96 mg/kg/. day, based on enlarged livers with increased weights, and hepatic microscopic lesions including Kupffer cell hyperplasia, inflammatory cell infiltration, and single cell necrosis in both sexes and on deposits of lipofuscin in males
-- Short-term inhalation (1 to 30 days)
-- Oral NOAEL = 18.8 mg/kg/ day
-- Residential LOC for MOE = 100
-- Occupational = 100
90-day rat feeding study.
The LOAEL for this study is 62.3 mg/kg/ day based on decreased hemoglobin, hematocrit, mean corpuscular hemoglobin, mean corpuscular volume, increased red cell volume distribution width, and increased incidence of bone marrow hypercellularity
-- Short-term incidental oral (1 to 30 days)
-- Intermediate-term incidental oral (1- 6 months)
-- LOAEL = 18.8 mg/kg/day
-- Residential LOC for MOE = 100
-- Occupational = NA
90-day rat feeding study.
The LOAEL for this study is 62.3 mg/kg/ day, based on decreased hemoglobin, hematocrit, mean corpuscular hemoglobin, mean corpuscular volume, increased red cell volume distribution width, and increased incidence of bone marrow hypercellularity
-- Short-term inhalation (1 to 30 days)
-- Intermediate-term inhalation (1 to 6 months)
-- Oral NOAEL = 18.8 mg/kg/day
-- Residential LOC for MOE = 100
-- Occupational = 100
Same as above
-- Long-term inhalation (>6 months)
-- Oral NOAEL = 1.2 mg/kg/day
-- Residential LOC for MOE = 100
-- Occupational = 100
Mouse oncogenicity study.
The LOAEL is 6.96 mg/kg/ day, based on enlarged livers with increased weights, and hepatic microscopic lesions including Kupffer cell hyperplasia, inflammatory cell infiltration, and single cell necrosis in both sexes and on deposits of lipofuscin in males
Aug 20, 2003 OPP-2003-0272 SYNGENTA: Registration Application for 2 pesticide products:
Products Containing Active Ingredients not Included in Any Previously Registered Products
-- 1. File symbol: 100-RRGA. Applicant: Syngenta Crop Protection. Inc., P.O. Box 18300, Greensboro, NC 27409. Product name: Butafenacil Technical. Active ingredient: Butafenacil at 98%. Proposed classification/Use: None. For formulation into herbicide end use products; for use as a cotton harvest aid.
-- 2. File symbol: 100-RRGT. Applicant: Syngenta Crop Protection. Product name: Inspire. Active ingredient: Butafenacil at 9.6%. Proposed classification/Use: None. For use as cotton harvest aid.
Feb 26, 2003 OPP-2003-0035 SYNGENTA: Pesticide Petition to Establish a Tolerance. PP 1F6309.
 
Fluoride Action Network | Pesticide Project | 315-379-9200 | pesticides@fluoridealert.org