A herbicide better known in organic circles as "compost killer" is being removed from home use.
The herbicide clopyralid is used in lawn sprays to maintain weed free lawns. Clopyralid
residues do not break down in composting, and tiny amounts of contaminated lawn
clippings could downgrade municipal composts, potentially damaging sensitive crops
such as potatoes and tomatoes.
"Soil & Health has long lobbied for the removal of clopyralid because it limits the
availability of municipal compost for organic vegetable growers" said spokesperson
Commercial composter Living Earth, through the New Zealand Business Council for
Sustainable Development, applied to ERMA to have clopyralid taken off the market.
Weedkillers containing the herbicide clopyralid will be taken off the retail market from
19 August 2008. Chlopyralid is sold in No Lawn Weeds, Clover and Prickle; Clopyd 300;
Void; Tango; Vivendi 300; Multiple; Contest; Pirate 300; Cardo; Versatill Herbicide;
Archer; AGPRO; Cloralid 300; Radiate; and Clout.
Soil & Health suggests retail customers check labels to ensure the chemical is removed
as soon as possible.
Toxin free urban home environment
Chemicals that require commercial operators to be trained in handling and use should
not be available for retail sale where purchasers may have no experience or training,
said Mr Browning.
“The urban home environment where most children live should be a toxin-free
ERMA’s continued allowance of clopyralid for agricultural weed control and
commercial turf management use meant there would still be composting piles of
contractors’ grass clippings that were useless for growing vegetables, said Mr
Compost doesn't breakdown toxin
Clopyralid requires UV sunlight to breakdown effectively and no matter how hot the
the compost heap gets inside, clopyralid persists, where other chemicals break down,
"Unfortunately ERMA hasn’t recognised that commercial and park operators were the
original problem when contamination was first noticed in the United States about 20
years ago. Grass collected by contractors is still going into a heap somewhere."
The still permitted use as an agricultural herbicide is also unnecessary as there are
non-clopyralid options, he said.
Still in use commercially
Where Clopyralid is still in use, a range of warnings will be used depending on the
clopyralid product, including 'The substance is not to be used on turf' and 'treated
vegetation shall not be disposed of at any green waste recycling centre.'
Soil & Health is concerned that carelessness will still result in contamination of compost
and the subsequent food chain.
Regardless of warning notices, contamination has occurred for decades said Mr
Grower's experience downplayed
“I have experienced it my previous glasshouse production several times and yet the
composters were being assured by contractors that their material was clean.”
ERMA’s statement also downgraded the very real experience of growers and
composters by stating that much of the information presented by the applicant
amounted to anecdotal evidence.
“Chemical industry statistical science does not make anecdotal evidence any less
valid. Precaution should not favour economics.”