P A N U P S
Pesticide Action Network
North America Updates Service
http://www.panna.org/panna/
April 1, 1997
Urge EPA to Deny Tolerance Enabling Use of Bromoxynil on Transgenic Cotton
The U.S. Environmental Protection Agency (EPA) is in the process of deciding
whether to renew a tolerance on cotton genetically engineered to tolerate
the herbicide bromoxynil (trade name Buctril). According to the Environmental
Defense Fund (EDF), new evidence indicates that this chemical is
even more hazardous than previously recognized. EDF feels that EPA should
deny renewal of the tolerance for bromoxynil, thus sending a strong signal
to industry that the Agency will not permit use of genetically engineered
herbicide-tolerant crops to promote expanded use of hazardous herbicides.
Bromoxynil is normally toxic to cotton, a broadleaf plant, and is used
on grass-like crops, such as corn, sorghum and small grains, to kill broadleaf
weeds. However, several years ago Rhone-Poulenc, the manufacturer of the
herbicide, and Calgene, a small California biotechnology company, teamed
up to engineer cotton so that it would tolerate the toxic effects of
bromoxynil, thus making it possible to apply the weed killer to cotton.
In 1995, EPA approved a conditional registration for bromoxynil on transgenic
bromoxynil-tolerant cotton under which the crop was grown commercially
in 1995 and 1996. EPA also established a temporary tolerance -- a maximum
permissible limit for the residues of bromoxynil in or on cottonseed, which
will expire April 1, 1997. Sometime within the next week or so, EPA will
decide whether to renew the tolerance. If it is renewed, the herbicide
could continue to be applied to transgenic cotton. If not, bromoxynil could
not be sold for use on cotton and there would be no reason to market bromoxynil-tolerant
cotton.
Bromoxynil is a toxic chemical with numerous adverse health and environmental
effects. A committee of EPA staff has concluded that bromoxynil should
retain its classification as Group C, a possible human carcinogen, based
on a new study submitted by Rhone- Poulenc showing that bromoxynil causes
malignant liver tumors in both female and male mice. Evidence of bromoxynil's
mutagenicity and information from a structural analog, 2,4,6-tricholorophenol,
a known carcinogen, provided additional support for the carcinogenicity
classification.
In addition, bromoxynil causes birth defects in laboratory mammals (rats,
mice, and rabbits) and has been classified by the Agency as a developmental
toxicant. In 1989, EPA canceled all registrations of pesticides containing
one form of bromoxynil -- bromoxynil butyrate -- because of the risk of
developmental toxicity in pesticide handlers. At that time, EPA also imposed
new measures, since relaxed somewhat, limiting occupational exposure to
avoid cancellation of other bromoxynil formulations (e.g., octanoate).
Bromoxynil also poses environmental threats -- it is highly toxic to broadleaf
plants and fish. Because it is a low-dose herbicide, even a small amount
accidentally misapplied or blown from the site of application threatens
wildlife habitats near fields. A study in ponds in the prairie-pothole
region of Canada demonstrated bromoxynil's toxicity to fish and showed
that the herbicide in water is readily converted to a toxic derivative
which persists for weeks after spray applications.
Given the new carcinogenicity data and the record on birth defects, the
Agency should not renew the tolerance for bromoxynil on transgenic cotton.
Also, this decision is being made by the Agency as it is implementing the
new Food Quality Protection Act (FQPA). This far reaching statute requires
a new tougher standard of safety, aggregate risk assessments, and special
protections for infants and children. The FQPA demands serious consideration
of chemicals that pose as many health and environmental hazards as bromoxynil,
and may facilitate EPA for the first time to say "no" to expanded
use of an herbicide on an herbicide-tolerant crop.
EDF urges you to write to EPA as soon as possible (a decision is likely
within a week) and ask the Agency to deny the renewal of the tolerance
for bromoxynil on cotton because
1) the herbicide presents a significant cancer risk and is a developmental
toxicant, and
2) expanding use of bromoxynil with a bromoxynil-tolerant crop violates
the Food Quality Protection Act's safety standard of "reasonable certainty
of no harm from aggregate exposure."
Address your letters to:
Dr. Lynn Goldman, Assistant Administrator, OPPTS, EPA,
401 M Street, SW, #642, Washington, DC 20460; fax (202) 260-1847.
Sources available
Contacts:
Rebecca Goldburg, Ph.D., Senior Scientist, Environmental Defense Fund,
257 Park Avenue South, New York, NY 10010;
phone (212) 505-2100; fax (212) 505-2375;
email becky@edf.org.
Richard Wolfson, PhD
Campaign to Ban Genetically Engineered Food
Natural Law Party
500 Wilbrod Street
Ottawa, ON Canada K1N 6N2
Tel. 613-565-8517 Fax. 613-565-6546
email: rwolfson@concentric.net
NLP Website (in progress): http://www.natural-law.ca
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