CHLORPYRIFOS

CHLORPYRIFOS

SUMMARY

Background

Chlorpyrifos is an organophosphate manufactured and marketed as an insecticide and acaricide . It is registered in most countries and sold under various names like Dursban, Lorsban, Chlorpyrifos and Termicide. By 1997, the US EPA reported that there were altogether 972 different Chlorpyrifos products registered.

Ever since the 1986 banning of Chlordane in Japan, Chlorpyrifos has often been used as a substitute for termite control in Japan and other countries where other widely used organochlorines were banned. According to US EPA, more than 20 million pounds of Dursban are used annually in the US.

Residue testing of chlorpyrifos by the USDA from 1993 to 1996 showed an increasing trend of samples with residues in fruits and vegetables. It was particularly high in apples where 19.3 to 26.4 per cent of samples were found to have residues.

According to the U.S. EPA, exposure to Chlorpyrifos poses the greatest problem to pregnant women and small children, with evidence of neurophysiological effects in humans. It has been found in animal tests that even low dose exposure to Chlorpyrifos can seriously affect the foetus, interfering with brain development and causing long-term neuro-chemical and behavioral deficits in off-springs. Newborns are at greater risk because of their lesser ability to detoxify.

EPA's decision to restrict use of chlorpyrifos is a result of the agency's evaluation of the insecticide under the 1996 Food Quality Protection Act. The act requires special protection for children and established an extra 10 fold safety factor for EPA to use when doing pesticide risk assessments.

Acute toxicity :

Reported effects: Exposure to chlorpyrifos has caused death or disability in humans. Lesser exposures may cause headache, dizziness, extreme weakness, unsteady movements, tiny pupils, twitching, tremors, nausea, slow heartbeat, fluid in the lungs, and sweating.

Poisoning Cases: Chlorpyrifos is a broad-spectrum insecticide and since it is so widely used, many insects that are not pests are killed along with the pests. Public health too has been put into jeopardy. Dr Janette Sherman, an independent physician from Virginia, reported 8 cases of serious and disabling birth defects seen in children whose mothers were exposed to Dursban during their first three months of pregnancies. These children have deformed heads, face, eyes and genitals and require constant care. In August 1998, a 67-year old Irishman was killed 6 days after helping to re-pot plants, without hand gloves, using granular chlorpyrifos.

Chronic toxicity:

Reported effects: Long term health effects in humans due to chlorpyrifos or its formulations may include weakness, loss of appetite, and also malaise.

According to the USDA, there is no acceptable level of chlorpyrifos in drinking water, although direct treatment of certain livestock is permitted with restrictions on time before slaughter.

Inert ingredients found in chlorpyrifos formulations include xylene, 1,2,4-trimethylbenzene, cumene, methyl chloroform, a petroleum solvent, and effects of exposure to these ingredients include possible reproductive effects, eye and skin irritation, possible mutagenic effects, central nervous system effects, anemia, bronchitis, and possible developmental effects.

All chlorpyrifos formulations may be fatal if swallowed, although formulated products are supposedly less acutely toxic than the technical chlorpyrifos. Excessive exposure to the solvent-based product may cause eye and upper respiratory irritation, central nervous system depression, increased sensitivity to epinephrine and irregular heartbeats.

No information is available indicating the presence of contaminants, but the EPA is requiring that chlorpyrifos be analyzed for the presence of potentially toxic dibenzodioxins which may form during manufacture.

The EPA analysis found exposure to Dursban on the skin, in food, or by inhaling it could be harmful to human health . Lab tests on rats have shown reproductive disorders but the two human studies by the EPA suggest that humans are as sensitive and possibly even more sensitive than animals.

Commenting on the US EPA's Partial Ban, Jay Feldman, executive director of Beyond Pesticides/National Coalition Against the Misuse of Pesticides (NCAMP) stated, "Nothing short of a ban of all uses of chlorpyrifos will protect the public from the chemical's adverse effects to the nervous system.”

On June 8, 2000 the US Environmental Protection Agency (EPA) announced a broad agreement with chemical manufacturers to phase-out the home and garden uses for the widely used insecticide chlorpyrifos. The agreement phases-out production of most home and garden uses of chlorpyrifos by the end of the year, permits sales through 2001, and allows existing stocks to be depleted. Uses that will be allowed to continue include all food uses (except tomatoes), golf courses, greenhouses, and mosquito and fire ant control. Spot and local treatment for termites (post-construction) will continue until December 21, 2002. New home treatment (pre-treat) will continue until December 31, 2005, while exposure to people in this situation is studied. Export of the product will continue without restriction However, environmentalists are urging that US homeowners, applicators and farmers stop their use and retailers stop sale of chlorpyrifos immediately in light of its known neurotoxic properties.

CHLORPYRIFOS PRODUCT CANCELLATIONS PROPOSED
On June 27, 01, EPA proposed to cancel or modify registrations for 94 products containing the pesticide chlorpyrifos. Companies holding end-use registrations for pesticide products containing chlorpyrifos have requested that EPA cancel or modify their registrations to meet the terms of the June 00 agreement between EPA and the registrants to reduce risks associated with the use of chlorpyrifos. EPA's announcement lists 76 products that will be canceled and 18 products for which labels will be modified to delete uses affected by the agreement. The agreement requires deletion of the following uses:

all termite control uses (these will be phased out and the concentration of chlorpyrifos in the products will be limited during the phase-out);

all residential uses (except for ant and roach baits in child resistant packaging (CRP) and fire ant mound drenches for public health purposes by licensed applicators and mosquito control for public health purposes by public health agencies);

all indoor non-residential uses (except ship holds, industrial plants, manufacturing plants, food processing plants, containerized baits in CRP, and processed wood manufacturing site or at the mill);

all outdoor non-residential sites (except golf courses, road medians, industrial plant sites, fence posts, utility poles, railroad ties, landscape timbers, logs, pallets, wooden containers, poles, posts, processed wood products, manhole covers, and underground utility cable and conduits; and

fire ant mound drenches for public health purposes by licensed applicators and mosquito control for public health purposes by public health agencies).

EPA must receive comments on these proposed cancellations and label modifications by July 27, 01, identified by docket control number OPP-34 3F. Information about the agreement to reduce risks associated with use of chlorpyrifos can be found on EPA's web site at www.epa.gov/pesticides/announcement6800.htm. The Federal Register notice announcing these proposed product cancellations is available atwww.epa.gov/fedrgstr/EPA-PEST/ 01/June/Day-27/p16125.htm

References

Beyond Pesticides/National Coalition Against the Misuse of Pesticides, Press Release, June 8, 2000.

Chlorpyrifos Pesticide Fact Sheet, Prepared for the U.S. Department of Agriculture, Forest Service by Information Ventures, Inc., (http://infoventures.com/e-hlth).

'Chlorpyrifos Residues in Air and Polished Rice Stock in a House Treated for Termite Control', by Seisaku Yoshida, Japan 1994.

Chlorpyrifos (Dursban)-associated birth defects: A proposed Syndrome, repeat of 4 cases, and discussions of the toxicology.- Sherman, J., 1996. USA-EPA, September 27, 1999.

'Death from OP Poisoning', Pesticides News # 46, December 1999.

'Dow Chemical Product May Hurt Human Health – EPA', by Julie Vorman, Reuters, October 29, 1999.

'EPA Takes Action on Chlorpyrifos, Finally', by Caroline Cox, Journal of Pesticide Reform/Summer 2000, Vol. 20 No. 2. Pg 13.

EPA Pesticide Program Update from EPA's Office of Pesticide Programs http://www.epa.gov/pesticides

'MAF's Toxic Spraying in Auckland' by Meriel Watts, Soil & Health, Vol. 59 No. 1, 2000. Pg 14.

PAN AP is one of the regional centres for PAN International - a global coalition of citizens' groups and individuals who work to promote sustainable agriculture. We are dedicated to ensuring the empowerment of people, especially women, agricultural workers, peasants and indigenous farmers. We are specially committed to protect the health and safety of people and the environment from pesticide use.

PAN AP, P.O. Box 1170, 10850 Penang, Malaysia.
Tel: (60-4) 657 0271, 656 0381 Fax: (60-4) 657 7445
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