Adverse Effects
Fluroxypyr
CAS No.
69377-81-7
 
 

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Abstracts

Activity: Herbicide (pyridine)
Structure:




Adverse Effects:
Ataxia
Body Weight Decrease
Bone
Endocrine: Adrenal
Endocrine: Testicular
Kidney
Mesenteric Lymph Node
Environmental

As of February 5, 2005, Fluroxypyr, a metabolite of Fluroxypyr 1-Methylheptyl ester, is permitted in or on 54 food commodities in the United States - - see list at bottom of page.

As to the following Table, we assume "Fluroxypyr" refers also to Fluroxypyr 1-Methylheptyl ester.

Fluroxypyr ranked number 9 for "Most Widely used pesticides in the UK (by Area Treated)"

Rank Formulation Method Area treated (ha) Weight applied (kg ai)
9 Fluroxypyr Spray 842,392 104,821

Ref: April 29, 2000. UK Department for Environment, Food & Rural Affairs in the online report, "Design of a Tax or Charge Scheme for Pesticides. " Annex C3: Overview of Pesticide Industry
http://www.fluorideaction.org/pesticides/pesticides.ranks.uk.2000.htm


Ataxia (click on for all fluorinated pesticides)

A 28-day feeding study in Beagle dogs administered Fluroxypyr 98.0% a.i. in the diet at levels of 0, 50, 150 or 450 mg/kg/day for 28 days. Dogs at 500 mg/kg/day exhibited ataxia and hind limb weakness as well as decreases in body weight and food consumption and were sacrificed on days 16/17 of the study. Histopathology showed moderate acute tubular nephrosis and a slight to moderate acute gastroenteritis. Some early signs of acute tubular nephrosis were also seen in both sexes of dogs at 150 mg/kg/day. The NOAEL for the study was 50 mg/kg/ day, the LOEL was 150 mg/kg/day based on histopathological lesions in the kidneys, decreased testes weights, and increased adrenal weights in both sexes.
Ref: Federal Register: September 30, 1998. Fluroxypyr; Pesticide Tolerance. Final Rule.

http://www.fluoridealert.org/pesticides/Fluroxypyr.FR.Sept.30.1998.htm

Body Weight Decrease (click on for all fluorinated pesticides)

-- In a range finding feeding study in dogs, dogs at 500 mg/kg/day exhibited ataxia and hind limb weakness as well as decreases in body weight and food consumption. Histopathology showed moderate acute tubular nephrosis and a slight to moderate acute gastroenteritis. Some early signs of acute tubular nephrosis were also seen in both sexes of dogs at 150 mg/kg/day. The NOEL for the study was 50 mg/kg/day, the LOAEL was 150 mg/kg/day based on histopathological lesions in the kidneys, decreased testes weights, and increased adrenal weights in both sexes.
-- In a developmental toxicity study in rats, fluroxypyr administration resulted in 8 deaths at the high-dose level, and decreased body-weight gain and food consumption during the dosing period at this dose level also. Clinical signs observed in those dying on test included staining of the skin/fur in the ano-genital area, lethargy, hypothermia, labored breathing, irregular gait, pale appearance. There were no treatment-related effects on gross pathologic alterations or absolute and relative liver and kidney weights at any dose level. The maternal NOEL is 300 mg/kg/day, the LOAEL is 600 mg/kg/day, based on deaths and decreased body-weight gain and food consumption. The developmental toxicity NOEL is 300 mg/kg/day, and the LOAEL is 600 mg/kg/day, based on an increase in two ossification variations (incompletely ossified cervical vertebral transverse processes and pubes).
Ref: U
S EPA. Pesticide Fact Sheet. Fluroxypyr. Reason for Issuance: Conditional Registration Date Issued: September 30, 1998.
http://www.epa.gov/opprd001/factsheets/fluroxypyr.pdf

Bone (click on for all fluorinated pesticides)

The developmental NOAEL is 250 mg/kg/day, the LOEL is 500 mg/kg/day based on reduced ossification... The developmental toxicity NOAEL is 300 mg/kg/day, and the LOEL is 600 mg/ kg/day, based on an increase in two ossification variations incompletely ossified cervical vertebral transverse processes and pubes.
Ref:
Federal Register. September 30, 1998. Fluroxypyr; Pesticide Tolerance. Final Rule.
http://www.fluoridealert.org/pesticides/Fluroxypyr.FR.Sept.30.1998.htm

Endocrine: Adrenal (click on for all fluorinated pesticides)

-- Chronic toxicity. EPA has established the RfD for fluroxypyr at 0.5 mg/kg/day. This RfD is based on histopathological lesions in the kidneys, decreased testes weights, and increased adrenal weights in both sexes observed in a 4-week range-finding feeding study in the dog with a NOAEL of 50 mg/kg/day. An uncertainty factor of 100 was used in calculating the RfD to account for both inter- and intra-species variations.
-- A 90-day feeding study in Wistar rats (10/sex/group) administered fluroxypyr (98.5% a.i.) in the diet at 0, 80, 750, 1,000 or 1,500 milligrams/kilogram/day (mg/kg/day) for 13 weeks. Significant nephrotoxicity and deaths were observed at 1,000 and 1,500 mg/kg/day in both sexes, and in males at 750 mg/kg/day. Death was due to renal papillary necrosis. Also observed were signs of ill health, emaciation, decreased food intake, increased kidney weight, histopathological lesions and decreased renal function. Histological changes were observed in the adrenals in both sexes at 1,000 and 1,500 mg/kg/day. In males the NOAEL for this study is 80 mg/kg/day, and the LOEL is 750 mg/ kg/day based on kidney effects and death. In females the NOAEL is 750 mg/kg/day, with the LOEL at 1,000 mg/kg/day based on kidney effects and death.
-- A 28-day feeding study in Beagle dogs administered Fluroxypyr 98.0% a.i. in the diet at levels of 0, 50, 150 or 450 mg/kg/day for 28 days. Dogs at 500 mg/kg/day exhibited ataxia and hind limb weakness as well as decreases in body weight and food consumption and were sacrificed on days 16/17 of the study. Histopathology showed moderate acute tubular nephrosis and a slight to moderate acute gastroenteritis. Some early signs of acute tubular nephrosis were also seen in both sexes of dogs at 150 mg/kg/day. The NOAEL for the study was 50 mg/kg/ day, the LOEL was 150 mg/kg/day based on histopathological lesions in the kidneys, decreased testes weights, and increased adrenal weights in both sexes.
Ref: Federal Register: September 30, 1998. Fluroxypyr; Pesticide Tolerance. Final Rule.

http://www.fluoridealert.org/pesticides/Fluroxypyr.FR.Sept.30.1998.htm

Endocrine: Testicular (click on for all fluorinated pesticides)

-- Chronic toxicity. EPA has established the RfD for fluroxypyr at 0.5 mg/kg/day. This RfD is based on histopathological lesions in the kidneys, decreased testes weights, and increased adrenal weights in both sexes observed in a 4-week range-finding feeding study in the dog with a NOAEL of 50 mg/kg/day. An uncertainty factor of 100 was used in calculating the RfD to account for both inter- and intra-species variations.
-- A 28-day feeding study in Beagle dogs administered Fluroxypyr 98.0% a.i. in the diet at levels of 0, 50, 150 or 450 mg/kg/day for 28 days. Dogs at 500 mg/kg/day exhibited ataxia and hind limb weakness as well as decreases in body weight and food consumption and were sacrificed on days 16/17 of the study. Histopathology showed moderate acute tubular nephrosis and a slight to moderate acute gastroenteritis. Some early signs of acute tubular nephrosis were also seen in both sexes of dogs at 150 mg/kg/day. The NOAEL for the study was 50 mg/kg/ day, the LOEL was 150 mg/kg/day based on histopathological lesions in the kidneys, decreased testes weights, and increased adrenal weights in both sexes.
Ref: Federal Register: September 30, 1998. Fluroxypyr; Pesticide Tolerance. Final Rule.

http://www.fluoridealert.org/pesticides/Fluroxypyr.FR.Sept.30.1998.htm

Kidney (click on for all fluorinated pesticides)

-- Chronic toxicity. EPA has established the RfD for fluroxypyr at 0.5 mg/kg/day. This RfD is based on histopathological lesions in the kidneys, decreased testes weights, and increased adrenal weights in both sexes observed in a 4-week range-finding feeding study in the dog with a NOAEL of 50 mg/kg/day. An uncertainty factor of 100 was used in calculating the RfD to account for both inter- and intra-species variations.
Ref: Federal Register: September 30, 1998. Fluroxypyr; Pesticide Tolerance. Final Rule.

http://www.fluoridealert.org/pesticides/Fluroxypyr.FR.Sept.30.1998.htm

-- In a range finding feeding study in dogs, dogs at 500 mg/kg/day exhibited ataxia and hind limb weakness as well as decreases in body weight and food consumption. Histopathology showed moderate acute tubular nephrosis and a slight to moderate acute gastroenteritis. Some early signs of acute tubular nephrosis were also seen in both sexes of dogs at 150 mg/kg/day. The NOEL for the study was 50 mg/kg/day, the LOAEL was 150 mg/kg/day based on histopathological lesions in the kidneys, decreased testes weights, and increased adrenal weights in both sexes.
-- In the carcinogenicity study in mice, there were no adverse effects on survival or clinical signs in either sex. There was no apparent treatment-related increase in the incidence of any tumor type in either sex. The LOAEL is 1000 mg/kg/day, based on decreased body weight/gain in males and an increased incidence of kidney lesions in females. The NOEL is 300 mg/kg/day.
-- In a developmental toxicity study in rats, fluroxypyr administration resulted in 8 deaths at the high-dose level, and decreased body-weight gain and food consumption during the dosing period at this dose level also. Clinical signs observed in those dying on test included staining of the skin/fur in the ano-genital area, lethargy, hypothermia, labored breathing, irregular gait, pale appearance. There were no treatment-related effects on gross pathologic alterations or absolute and relative liver and kidney weights at any dose level. The maternal NOEL is 300 mg/kg/day, the LOAEL is 600 mg/kg/day, based on deaths and decreased body-weight gain and food consumption. The developmental toxicity NOEL is 300 mg/kg/day, and the LOAEL is 600 mg/kg/day, based on an increase in two ossification variations (incompletely ossified cervical vertebral transverse processes and pubes).
Ref: US EPA. Pesticide Fact Sheet. Fluroxypyr. Reason for Issuance: Conditional Registration Date Issued: September 30, 1998.
http://www.epa.gov/opprd001/factsheets/fluroxypyr.pdf

870.4300 Carcinogenicity--Rats NOAEL = 100 mg/kg/day. LOAEL = 500 mg/kg/day based on chronic progressive kidney glomerulonephropathy (M&F).(no) evidence of carcinogenicity.
Ref: Federal Register. December 31, 2003. Fluroxypyr; Pesticide Tolerance. Final Rule.
http://www.epa.gov/fedrgstr/EPA-PEST/2003/December/Day-31/p32007.htm

Mesenteric Lymph Node (click on for all fluorinated pesticides)

In the combined chronic toxicity/carcinogenicity study in rats, fluroxypyr 99.0% a.i. was administered to 50 Fischer 344 rats/sex/dose via the diet at dose levels of 0, 100, 500, and 1,000, females only,
mg/kg/day for 24 months 10 rats/sex/dose for 12 months. There was no apparent increase in the incidence of kidney tumors in either sex. With the exception of an increased incidence of parafollicular cell adenomas, single only, in males at 500 mg/kg/day, at the doses tested, there was no apparent treatment-related increase in any tumor type in either sex. The LOEL is 500 mg/kg/day, based on increased kidney weight in both sexes, increased incidence of atrophy, adipose tissue mesenteric tissues in males and an increase in the severity of chronic progressive glomerulonephropathy in the kidney in both sexes. The NOAEL is 100 mg/kg/day. Deaths occurred at 1,000 mg/kg/day in males within the first 90 days on test 2 by day 28 and 3 more by day 56.
Ref: Federal Register. Fluroxypyr (Dow Agro). September 30, 1998. Pesticide Tolerance. Final Rule.
http://www.fluoridealert.org/pesticides/fluroxypyr.fr.sept.30.1998.htm

Environmental (click on for all fluorinated pesticides)

-- The data available at this time indicate that fluroxypyr is highly phytotoxic.
-- Aquatic - Estuarine/Marine Fluroxypyr is slightly toxic to the silverside (96-hour LC 50 = 40 mg/L). Fluroxypyr acid is highly toxic to the eastern oyster (96-hour LC 50 /EC 50 = 0.068 mg/L); fluroxypyr 1-methylheptyl ester is slightly toxic to the eastern oyster (96-hour LC 50 /EC 50 = 51 mg/L). It is practically non-toxic to the grass shrimp (96-hour LC 50 /EC 50 > 120 mg/L). Fluroxypyr is highly toxic terrestrial plants. Seedling emergence studies identified the most sensitive species to fluroxypyr methylheptyl ester being the cucumber (EC 25 = 0.075 pounds active ingredient/acre). Since fluroxypyr methylheptyl ester may degrade to fluroxypyr acid before reaching non-target plants, seedling emergence studies were performed on fluroxypyr acid and identified cotton as the most sensitive species (EC 25 = 0.025 pounds active ingredient/acre). Vegetative vigor studies with fluroxypyr methlyheptyl ester also identified cotton as the most sensitive species (EC 25 = 0.0012 pounds active ingredient/acre).

Ref: US EPA. Pesticide Fact Sheet. Fluroxypyr. Reason for Issuance: Conditional Registration Date Issued: September 30, 1998.
http://www.epa.gov/opprd001/factsheets/fluroxypyr.pdf


A February 5, 2005, check at the Code of Federal Regulations for Fluroxypyr 1-Methylheptyl ester and its metabolite Fluroxypyr: they are permitted in or on 54 food commodities in the United States. The following list identifies these commodities for which EPA has set pesticide tolerances. 

[Code of Federal Regulations]
[Title 40, Volume 22]
[Revised as of July 1, 2004]
From the U.S. Government Printing Office via GPO Access
[CITE: 40CFR180.535]
[Page 494-495]

TITLE 40--PROTECTION OF ENVIRONMENT

CHAPTER I--ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)

PART 180_TOLERANCES AND EXEMPTIONS FROM TOLERANCES FOR PESTICIDE CHEMICALS
IN FOOD--Table of Contents

Subpart C_Specific Tolerances

Sec. 180.535 Fluroxypyr 1-methylheptyl ester; tolerances for residues.
(a) General. Tolerances are established for combined residues of
fluroxypyr 1-methylheptyl ester
[1-methylheptyl ((4-amino-3,5-dichloro-
6-fluoro-2-pyridinyl)oxy)acetate] and its metabolite fluroxypyr [((4-
amino-3,5-dichloro-6-fluoro-2-pyridinyl)oxy)acetic acid] in or on the
following raw agricultural commodities.

Commodity

Parts per Million

PPM

US Code of Federal Regulations

CFR

Barley, grain 0.5 180.535
Barley, forage 12.0 180.535
Barley, hay 20.0 180.535
Barley, straw 12.0 180.535
Cattle, fat 0.1 180.535
Cattle, kidney 1.5 180.535
Cattle, meat 0.1 180.535
Cattle, meat byproducts 0.1 180.535
Corn, field, forage 1.0 180.535
Corn, field, grain 0.02 180.535
Corn, field, stover 0.5 180.535
Corn, sweet, forage 1.0 180.535
Corn, sweet, kernel plus cob with husks removed 0.02 180.535
Corn, sweet, stover 2.0 180.535
Goat, fat 0.1 180.535
Goat, kidney 1.5 180.535
Goat, meat 0.1 180.535
Goat, meat byproducts 0.1 180.535
Grain, aspirated fractions 0.6 180.535
Grass, forage 120 180.535
Grass, hay 160 180.535
Hog, fat 0.1 180.535
Hog, kidney 1.5 180.535
Hog, meat 0.1 180.535
Hog, meat byproducts 0.1 180.535
Horse, fat 0.1 180.535
Horse, kidney 1.5 180.535
Horse, meat 0.1 180.535
Horse, meat byproducts 0.1 180.535
Milk 0.3 180.535
Oat, forage 12.0 180.535
Oat, grain 0.5 180.535
Oat, hay 20.0 180.535
Oat, straw 12.0 180.535
Sheep, fat 0.1 180.535
Sheep, kidney 1.5 180.535
Sheep, meat 0.1 180.535
Sheep, meat byproducts 0.1 180.535
Sorghum, grain, forage 2.0 180.535
Sorghum, grain, grain   0.02 180.535
Sorghum, grain, stover 4.0 180.535
Wheat, forage 12.0 180.535
Wheat, grain 0.5 180.535
Wheat, hay 20.0 180.535
Wheat, straw 12.0 180.535
(b) Section 18 emergency exemptions. Time-limited tolerances are
established for the combined residues of fluroxypyr 1-methylheptyl ester
and its metabolite fluroxypyr
, in connection with use of the pesticide
under section 18 emergency exemptions granted by EPA. The tolerances
will expire and are revoked on the dates specified in the following table.
Commodity PPM Expiration/Revocation Date
Corn, field, forage 2.0 12/31/06
Corn, field, grain 0.05 12/31/06
Corn, field, stover 2.5 12/31/06
Corn, sweet, forage 2.0 12/31/06
Corn, sweet, kernel plus cob with husks removed 0.05 12/31/06
Corn, sweet, stover 2.5 12/31/06
Onion 0.02 6/30/07
Sorghum, grain, forage 2.0 12/31/05
Sorghum, grain, grain 0.035 12/31/05
Sorghum, grain, stover 4.0 12/31/05
Cattle, kidney 1.5 12/31/04
Goat, kidney 1.5 12/31/04
Grass, forage 120 12/31/04
Grass, hay 160 12/31/04
Hog, kidney 1.5 12/31/04
Horse, kidney 1.5 12/31/04
Milk 0.30 12/31/04
Sheep, kidney 1.5 12/31/04
(c) Tolerances with regional registrations. [Reserved]
(d) Indirect or inadvertent residues. [Reserved]

 

 
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