(aryloxyphenoxy propionic acid)
(only comprehensive for the US)
EPA PC Code:
(includes only a limited list of countries)
Phillipines, US, Vietnam
Maximum Residule Level (MRL)
Maximum Residue Levels permitted
in food commodities
for Cyhalofop-butyl, Cyhalofop acid and the di-acid metabolite:
Rice (grain and straw)
2005 - Evaluation of
the new active Cyhalofop-Butyl in the product Barnstorm Herbicide.
Australian Pesticides and Veterinary Medicines Authority (APVMA).
Canberra, Australia. Barnstorm herbicide is proposed to be used
for the post emergence control of barnyar grasses and silver
top grass in rice. Cyhalofop-butyl is manufactured in Japan.
Barnstorm Herbicide will be formulated in New Zealand and transported
to Australia fully packed. The label recommends both ground
and aerial applications. Almost all applications (~95%) are
expected to be aerially applied with just ~5 % applied by groundrigs.
16, 2001 -
Summary of Toxicological data (Cyhalofop-Butyl). California
Environmental Protection Agency. Department of Pesticide Regulation.
Medical Toxicology Branch.
European Commission Health & Consumer Protection Directorate-General.
Review report for the active substance
cyhalofop-butyl. Finalised in the Standing Committee on the
Food Chain and Animal Health at its meeting on 19 April 2002
in view of the inclusion of cyhalofop-butyl in Annex I of Directive
18, 2002 - European
Commission decision to extend provisional authorisation
for new active substances including cyhalofop-buty
of Pesticide Chemicals,
October 2001. A listing of pesticides subject to analysis of
residues in foods and feeds by the US Food and Drug Administration.
Also available at: http://vm.cfsan.fda.gov/~acrobat/pestglos.pdf
Products/Transitional Solution List - This
list contains brief descriptions of numerous new pest control
materials that have been introduced over the last several years.
Additionally, it contains information on some "older"
crop protection chemicals that are believed to have room for
new uses. This List includes Cyhalofop-butyl.
Note: Not all entries are listed below. Click
here to view all FR entries.
pesticide tolerance for combined residues
(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.
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.
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.
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.
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.
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
was the reason for enlarged livers.
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.
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
was observed in 2/ 5 males on day 2 only. Delayed weight
gain was observed in all rats, with the females being most
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.
Arizona. EPA authorized the use
of cyhalofop-buty on rice to control bearded sprangletop; April
15, 2002 to August 15, 2002.