Pyraflufen-ethyl
CAS No. 129630-19-9
US Federal Register
 
 

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Adverse Effects

ACTIVITY: Herbicide (pyrazolylphenyl)

CAS Name for Pyraflufen: [2-chloro-5-[4-chloro-5-(difluoromethoxy)-1-methyl-1H-pyrazol-3-yl]-4-fluorophenoxy]acetic acid

NOTES: This compound is normally used as a salt or an ester, the identity of which should be stated, for example pyraflufen-ethyl.

Structure for Pyraflufen:

US Federal Register

Date Published Docket Identification Number Details

June 27, 2007

 

EPA-HQ-OPP-2007-0366

Nichino America, Inc. Pesticide Petition. PP 7F7190. Proposal to establish a tolerance for residues of the herbicide, pyraflufen-ethyl and its acid metabolite, E-1 (2-chloro-5-(4-chloro-5-difluoromethoxy-(1-methyl-1H- pyrazol-3-yl)-4-fluorophenoxyacetic acid), expressed in terms of the parent in or on food commodities:

Soybeans, forage 0.05 ppm
soybeans, hay 0.1 ppm

grass, forage, crop group 17

1.0 ppm
grass, hay, crop group 17 1.2 ppm

Aqueous organic solvent extraction, column clean up, and quantitation by GC is used to measure and evaluate the chemical residues.

May 21, 2003

OPP-2003-0163

NICHINO AMERICA. Pesticide Tolerance. FINAL RULE. This regulation establishes a tolerance for combined residues of pyraflufen and pyraflufen-ethyl in or on
-- Cotton, gin byproduct............ 1.5
-- Cotton, undelinted seed........0.04
-- Cancer
Classification: ``Likely to be Carcinogenic to Humans'' by the oral route Q1* = 3.32 x 10-2 (mg/kg/day)-1
-- Inhalation1 long-term (< 6 months) Oral NOAEL= 20 1X Mouse carcinogenicity. LOAEL = 98 mg/kg/day based on liver toxicity.
-- Inhalation1 intermediate-term (1-6 months) Oral NOAEL= 20 1X Mouse carcinogenicity. LOAEL = 98 mg/kg/day based on liver toxicity at interim sacrifice.
-- Inhalation1 short-term (1-30 days) Oral NOAEL= 20 1X Developmental toxicity- rabbit. LOAEL = 60 mg/kg/day based on decreases in bwt and food consumption, GI observations, and abortions.
-- Chronic dietary. Mouse carcinogenicity. Chronic RfD = 0.20 mg/ kg/day. LOAEL = 98 mg/kg/day. based on liver toxicity.
--
Pyraflufen-ethyl is currently registered for use on the following residential non-dietary sites: Airports, nurseries, ornamental turf, golf courses, roadsides, and railroads.

April 30, 2003 OPP-2003-0110.

Nichino America. Pesticide tolerances. FINAL RULE established for combined residues of the herbicide pyraflufen-ethyl (ethyl 2-chloro-5-(4-chloro-5-difluoromethoxy-1- methyl-1H-pyrazol-3-yl)-4-fluorophenoxyacetate) and its acid metabolite, E-1 (2-chloro-5-(4-chloro-5-difluoromethoxy-1-methyl-1H- pyrazol-3-yl)-4-fluorophenoxyacetic acid), expressed as the ester equivalent in or on

Commodity Parts per million
Corn, field, forage 0.01
Corn, field, grain 0.01
Corn, field, stover 0.01
Potato 0.02
Soybean, forage 0.01
Soybean, hay 0.01
Soybean, seed 0.01

-- Cancer Classification: ``Likely to be Carcinogenic to Humans'' by the oral route.
-- Mouse Carcinogenicity LOAEL = 98 mg/kg/day based on liver toxicty
-- Developmental toxicity- rabbit. LOAEL = 60 mg/kg/day based on decreases in bwt and food
consumption, GI observations, and abortions

-- Note from FAN; this metabolite is Pyraflufen.

Nov 20, 2002 OPP-2002-0126  Nichino America. Pesticide petition to establish tolerances for combined residues of pyraflufen-ethyl and its acid metabolite in or on the raw agricultural commodities (RACs) derived from cotton; undelinted seed at 0.05 ppm; and gin byproducts at 1.5 ppm; in or on the RAC potato at 0.02 ppm; in or on the RACs corn grain, corn stover, corn forage, soybean seed, soybean forage, and soybean hay at 0.01 ppm; wheat forage, wheat hay, wheat straw, and wheat grain at 0.01 ppm.

It is being proposed that pyraflufen-ethyl be registered in the following non-food sites: airports, commercial plants, fence lines, farmyards, and farm buildings; storage and lumber yards; barrier strips and firebreaks; equipment areas, nurseries and ornamental plantings; established ornamental turf; railroad, roadside, and utility rights-of-ways; dry ditches and ditch banks; fuel tank farms and pumping stations; other similar non-crop areas

-- Rabbits fed pyraflufen-ethyl at 0, 20, 60, or 150 mg/kg/day, resulted in severe maternal toxicity, including lethality, from gastrointestinal irritation at doses of 60 and 150 mg/kg/day. The maternal NOAEL was 20 mg/kg/day.
The NOAEL for the offspring was 60 mg/ kg/day, based on increased post-implantation loss observed at 150 mg/ kg/day.
-- A 90-day rat feeding study was conducted at dose levels of 0, 200, 1,000, 5,000, or 15,000 ppm pyraflufen-ethyl. The NOAEL in this study was considered to be 1,000 ppm (85.6 mg/kg/day for males and 95.4 mg/ kg/day for females), based on slightly increased phosphorous concentrations in females and hepatocytic hypertrophy in males at 5,000 ppm. In addition, the highest dose of 15,000 ppm resulted in erythocyte toxicity, mitochondrial changes in the hepatocytes and the presence of Kupffer cells. Also, at the high dose level increased kidney weights in males and increased absolute and relative spleen weights in both sexes were observed.
-- In a 2-year chronic toxicity/oncogenicity study, pyraflufen-ethyl was administered to CD rats at dietary levels of 0, 80, 400, 2,000, or 10,000 ppm (equivalent to 0, 3.4, 17.2, 86.7, and 468.1 mg/kg/day for males and 0, 4.4, 21.8, 111.5, and 578.5 mg/kg/day for females). Mortality was unaffected by treatment. Body weight gain was statistically significantly depressed for those rats fed 10,000 ppm at 1-year compared to the control. Treatment-related histopathology was seen in the kidney, liver, and bile duct at 10, 000 ppm. At 2,000 and 10,000 ppm, vacuoles within the mitochondria of centriacinar and periacinar hepatocytes were seen. Effects on urine volume, urine specific gravity, and kidney weights were seen at 2,000 ppm in males. The NOAEL was 17.2 mg/kg/day for males and 21.8 mg/kg/day for females. No evidence of carcinogenicity was observed.
-- In a 78-week carcinogenicity study, mice were fed pyraflufen-ethyl in the diet at levels of 0, 200, 1,000, or 5,000 ppm (equivalent to 0, 21, 110, 547 mg/kg/day for males and 0. 20, 98, 524 mg/kg/day for females). An maximum tolerance dose (MTD) was reached at 1,000 ppm, based on increased liver weight and liver histopathological changes (including necrosis) seen at this feeding level. In the highest dose group, effects of pyraflufen-ethyl on hematological parameters were observed. The incidence of hepatocellular adenoma was increased in animals receiving 5,000 ppm, compared to controls. This benign tumor was likely induced by the adaptive response to the hepatocellular degeneration and not as a result of any genotoxic potential of pyraflufen-ethyl. In addition the response was observed only at a dose level that was in excess of an MTD.

Nov 13, 2002 OPP-2002- 0279 Nichino America. Pyraflufen-ethyl. Pesticide Products; Registration Applications.

1. File symbol: 71771-T. Product name: ET-751 2.5% EC Herbicide. Product type: Herbicide. Active ingredient: Pyraflufen-ethyl (ethyl 2-chloro-5-(4-chloro-5-difluoromethoxy-1-methylpyrazol-3-yl)-4- fluorophenoxyacetate) at 2.5%. Proposed classification/Use: None. For use on terrestrial non-cropland to control broadleaf weeds.

2. File symbol: 71711-A. Product name: ET-751 Technical. Product type: Herbicide. Active ingredient: Pyraflufen-ethyl at 97.9%. Proposed classification/Use: None. For manufacturing use of end-use products to be used to control certain broadleaf weeds on terrestrial non-cropland.

 
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