FWD: Compost Contaminated with Clopyralid
Santoyo & Associates
santoyo at earthflow.com
Fri Dec 14 18:11:53 EST 2001
P A N U P S
Pesticide Action Network Updates Service
Compost Contaminated with Clopyralid
December 11, 2001
For the second year in a row, the persistent herbicide clopyralid has
contaminated compost at two composting facilities in the U.S. state of
Washington. Produced exclusively by Dow AgroSciences and available
commercially under the name Confront, Clopyralid has recently
contaminated compost in New Zealand and in the U.S. state of
Pennsylvania, according to the U.S. Composting Council.
Confront is used on lawns to kill dandelions, clover and other broadleaf
plants. Although most herbicides are considered to break down during
composting, clopyralid and others in the pyridine carboxylic acid group
break down extremely slowly, especially during composting.
In Washington, plants treated with Confront have contaminated compost at
local composting facilities with levels of clopyralid high enough to
cause damage to compost users' crops, including those at local gardens
and nurseries. Publicly available studies show low acute toxicity to
humans and animals, but no data on reproductive effects, developmental
effects or cancer are available. Clopyralid is quite soluble in water,
mobile in soil and extremely toxic to certain plants. Sunflowers,
legumes, tomatoes and potatoes can be affected by clopyralid at levels
of 10 parts per billion (ppb) or less.
Clopyralid contamination has prevented the Spokane Regional Composting
Facility in Washington from selling compost to the general public this
year, and 25,000 cubic yards of compost remain unsold from last year.
Tests in May 2001 at the facility revealed clopyralid residue levels of
73 and 80 ppb. At Washington State University, loss of revenue, settling
claims, testing and additional labor due to clopyralid contamination has
cost the facility about US$250,000 over the past two years.
Critics charge that the contamination undermines the investment of
millions of dollars in public and private composting facilities and
threatens consumer confidence in composting facilities' reputation for
providing quality products.
"Confront is totally contradictory to all of our goals for recycling,
resource conservation and sustainability... Dow must follow the
precautionary principle and withdraw Confront immediately until it can
be proven safe for organics recycling," commented Ann Morse, president
of GrassRoots Recycling Network in Georgia. "Dow must take full
responsibility for damage caused by its products," she added.
In April 2001, the city and county of Spokane, Washington asked Dow to
stop distributing clopyralid temporarily in their local area. The
company agreed to do so for residential uses, but the herbicide will
still be used on golf courses whose grass is not taken to composting
facilities. The city has also begun a campaign to educate people about
why herbicide treated grass cannot be composted. Washington State
University has responded by certifying vendors of straw and hay--the
main crops suspected of carrying clopyralid. Vendors will have to
guarantee that their crops are herbicide free.
Fearing that the contamination may be more widespread than several
isolated incidents, the Washington Organics Recycling Council has asked
all composting facilities in the state to start monitoring for
Public utilities in the U.S. states of Washington and Oregon urged the
U.S. Environmental Protection Agency (EPA) to reconsider its
registration and re-registration criteria for herbicides to include the
requirement that no residual herbicides remain after a normal 60 to 90
day composting cycle. The utilities emphasized that herbicide
manufacturers, not composting facilities, should be held responsible for
The U.S. Composting Council and other groups have called for Dow to work
with the EPA to develop clearer warning labels on clopyralid products.
Currently, the labels warn not to use compost containing grass clippings
that were sprayed with clopyralid during the same season as spraying
occurred. However, the two cases in Washington show that contamination
can persist beyond a single season.
The Council has called upon Dow to buy the contaminated compost,
compensate organic growers for lost produce, compensate composters for
costs of remediating clients' land and fund an independent study into
the effects of clopyralid--including testing the amount of clopyralid
that passes through to the urine of animals and humans who consume
treated grain, asparagus, beets or their byproducts.
In 2000, Dow was the fifth largest agrochemical company in the world
with sales of over US$2.2 billion dollars.
Sources: Bezdicek, David, Mary Fauci, Dan Caldwell, Rick Rinch and
Jessie Lang, "One Year Later: Persistent Herbicides in Compost,"
BioCycle: Journal of Composting and Organics Recycling July 2001; Joe
Truini, "Composting Council says Dow's Herbicide Product Poisons
Compost" Waste News, November 12, 2001; Washington State University
press release, June 13, 2001; Agrow: World Crop Protection News,
Janurary 5, March 2 and April 13, 2001.
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