Adverse Effects:

Body Weight Decrease
Carcinogenicity: Kidney
Endocrine: Testicular
Endocrine: Thymus
Eye
Kidney
Liver

February 16, 2001 - Summary of Toxicological data (Cyhalofop-Butyl). California Environmental Protection Agency. Department of Pesticide Regulation. Medical Toxicology Branch.

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 ]