Cyhalofop-butyl
CAS No. 122008-85-9
US Federal Register
 
 

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Adverse Effects

ACTIVITY: Herbicide (aryloxyphenoxy propionic acid)

Structure for Cyhalofop:

US Federal Register

Date Published Docket Identification Number Details
June 4. 2002 OPP-2002-0087

5-Year pesticide tolerance for combined residues of cyhalofop (cyhalofop-butyl plus cyhalofop-acid) and the di-acid metabolite in or on rice grain at 0.03 ppm and rice straw at 8.0 ppm. Final Rule.

  • Dermal, Long-Term, Carcinogenicity in Mice: Kidney effects in females including tubular dilatation, chronic glomerulonephritis, and hyaline casts at the LOAEL of 10.06 / 10.28 mg/kg/day, M/F.
  • Inhalation, Short- Term (1-30 days), Subchronic Feeding Mice: Enlarged kidneys in Enlarged kidneys in swelling of the proximal tubule cells in 4/12 mice at the LOAEL of 14.1 mg/kg/ day.
  • Inhalation, Long- Term ( 6 months), Carcinogenicity in Mice: Kidney effects in females including tubular dilatation, chronic glomerulonephritis, and hyaline casts at the LOAEL of 10.06 / 10.28 mg/kg/day, M/F.
  • Cancer: This herbicide has not been classified. The rat and mouse carcinogenicity studies are identified as data gaps. Since the doses tested in these studies were too low to assess the carcinogenic potential of cyhalofop- butyl, the cancer dietary risk assessment was conducted using the potency factor (Q1*) of 2.3 x 10-\1\ for the structural analog diclofop- methyl.
  • Special Study Hepatocellular Proliferation in Rats: In a subchronic oral toxicity study in rats (MRID 45000413), satellite rats dosed for 4 weeks had hepatocellular hypertrophy and focal necrosis at all dose levels... An initial dramatic increase in DNA synthesis during the first week of treatment was followed by hepatocellular hypertrophy at subsequent observations. This was the reason for enlarged livers.
  • In Vitro Chromosomal Aberration in Chinese Hamster Lung: Polyploidy was induced when CHL (V79) cells were treated for 48 hours in the absence of S9, but there was no clastogenic effect on DNA.
    [FAN Note: Polyploidy is when the number of chromosomes in a cell becomes doubled. One obvious consequence is that the resulting creature has no one it can breed with. Ref: http://www.cs.colorado.edu/~lindsay/creation/polyploidy.html ]
  • Acute Dermal (Rat): Chromodacryorrhea was observed in 2/ 5 males on day 2 only. Delayed weight gain was observed in all rats, with the females being most affected.

    [FAN Note:
    Chromodacryorrhea or red tears due to excessive production of Harderian gland secretions. The glands, named after the Swiss physician Johann Jakob Harder, are exocrine glands located deep within the orbit. The Harderian gland secretes mostly lipids in the rat. Further products include porphyrin and melatonin. Various physiological functions have been attributed to the rat Harderian gland. The lipid-containing part of the secretion may serve to lubricate the eye. Some observations suggest a behavior related odoriferous (pheromonal) role. The Harderian gland is also considered to serve, like the pineal gland, as an extraretinal photoreceptor. Harderian porphyrin may have a photoprotective role, as it is increasingly secreted in response to light exposure and as porphyrins show an intense absorption of light. Chromodacryorrhea is a consequence of acute-onset stress such as pain, illness, restraint, or poisoning. Red tears are often an indication of a chronic underlying disease, and warrant a thorough evaluation of affected animals. Ref:
    http://www.labanimal.com/col/diag1.html ]

Feb 13, 2002 na Cyhalofop-butyl: Emergency Exemptions:
Arizona. EPA authorized the use of cyhalofop-buty on rice to control bearded sprangletop; April 15, 2002 to August 15, 2002.
Sept 27, 2001 OPP-301167

Pesticide Tolerances for Emergency Exemptions. - FINAL RULE. Cyhalofop-butyl is a new chemical, this is the first tolerance established for the combined residues of cyhalofop-butyl plus the cyhalofop-acid and di-acid metabolites, in or on a raw agricultural commodity rice grain at 0.03 ppm and rice straw at 8.0 ppm. These tolerances will expire and are revoked on June 30, 2002.

  • Chronic dietary all populations: Carcinogenicity in mice LOAEL = 10.06 mg/kg/day based on kidney effects in females including tubular dilatation, chronic glomerulonephritis, and hyaline casts.
  • Long-term dermal (greater than 6 months): Carcinogenicity in mice LOAEL = 10.06 mg/kg/day based on kidney effects in females including tubular dilatation, chronic glomerulonephritis, and hyaline casts.
  • Short-term inhalation (1 to 30 days) and intermediate-term inhalation (1-6 months) (residential): Subchronic feeding study in mice LOAEL = 14.1 mg/kg/day based on enlarged kidneys in females accompanied by swelling of the proximal tubule cells.
  • Long-term inhalation (greater than 6 months) (residential): LOAEL = 10.06 mg/kg/day based on kidney effects in females including tubular dilatation, chronic glomerulonephritis, and hyaline casts.
  • Objections and requests for hearings, identified by docket control number OPP-301167, must be received by EPA on or before November 26, 2001.
April 25, 2001 PF-1009

DOW AGRO - Petition to Establish Tolerances for residues of cyhalofop-butyl in or on rice grain, rice hull, rice bran, and polished rice at 0.03 ppm for grain and 8.0 ppm for straw.

 
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