State Department report to Congress on effects on human health and safety of herbicides used in the Colombian aerial spray program, January 23, 2001

Human Health and the Safety of Herbicides

Glyphosate is a non-selective herbicide. It is the active ingredient in several formulations that are sold under various tradenames throughout the world. The U.S. Environmental Protection Agency (EPA) reregistered glyphosate as an active ingredient after review and evaluation of a large number of studies (more than 200) describing the human health and environmental fate and effects of glyphosate. Their evaluation determined that the use of glyphosate, as labeled for use in the U.S., is acceptable provided that the regulatory controls required by the EPA - the labeled instructions - - are followed. This September 1993 Reregistration Eligibility Decision (RED) determined the risks only for glyphosate, and its formulated products. Another reassessment by EPA in 2000 of the available toxicology studies confirmed glyphosate's acceptability; as a result, additional uses on food crops were approved.

Formulated pesticide products usually contain chemicals other than the active ingredients to assure that the active ingredient performs in an effective manner at the appropriate concentration. The other chemicals in the formulated products are referred to as inert (other) ingredients, and they function as solvents, emulsifying agents, thickeners, carriers, or preservatives. The term inert means only that the ingredient is not performing an active pesticide function.

The EPA has developed several lists of chemicals that are approved for use as inert (other) ingredients in pesticide products. The inert ingredients approved for use in pesticide formulations used on food crops and on livestock animals are set forth in the Code of Federal Regulations (40 C.F.R. § 180.1001 (c), (d), and (e)). Each formulated product must be registered (or "licensed") with EPA before being offered for sale and use. As part of the process to obtain this registration, the formulator must submit a listing of the chemicals used to make the product and a battery of chemistry and toxicity studies. EPA will not register a formulated product for use on food crops or animals unless (1) the active ingredient is registered, (2) all ingredients are granted tolerances of residues or exemption from the requirement of a tolerance as set forth in 40 C.F.R. § 180.1001(c), (d), and (e), and (3) EPA makes a finding that the use of the product will not cause an unreasonable adverse effect to humans or the environment.

Two adjuvants (COSMO FLUX-411F and COSMO-IN-D), the glyphosate product, and water are mixed together to make the spray solution. These two adjuvants are proprietary products that increase the effectiveness of the spray solution. It should be noted that EPA does not regulate adjuvants, as they are not pesticide products as defined by the Federal Insecticide, Fungicide, and Rodenticide Act. The seller of these adjuvants voluntarily provided the mixture ingredient lists with their Chemical Abstract Service (CAS) numbers for a review by the EPA. The EPA reviewed the lists of ingredients for the two adjuvants and determined that the ingredients in both adjuvants are listed in 40 CFR 180.1001. Therefore, both adjuvants are acceptable for use on food crops when the label instructions are followed.

Coca Aerial Eradication Chemicals

The Government of Colombia (GOC) attacks the coca crop primarily through aerial spraying using the herbicide glyphosate. The GOC has chosen to attack the coca crop primarily by spraying herbicides from the air rather than going into the fields and manually cutting down the crop for cost, efficiency. and safety reasons. All of these reasons relate to Colombia's coca crop being:

o Enormous (122,500 hectares) and expanding (having tripled in size since 1993);
o Widely dispersed (ranging from southeast to southwest Colombia. and in the north); and
o Concentrated increasingly in guerrilla-dominated areas.

It would be nearly impossible--tactically and financially--to match the pace and breadth of expansion by dispatching teams to eradicate the coca fields manually. It would be equally as difficult to protect these workers, or their security forces, from the certain and deadly violence that would escalate as they encountered hostile coca growers, insurgents and paramilitary forces protecting illicit fields. Herbicide application by airplane is the most cost-effective way of coping with the magnitude of the problem and ensuring that eradication operations do not turn violent. Spray programs can more quickly and easily adjust their operations to mitigate potential violence in the face of a likely confrontation with hostile growers and their defenders than can eradication teams on the ground.

We disagree with the perception that GOC uses extremely toxic chemicals in this operation and believe that switching to "less effective" chemicals would risk undermining the eradication effort and increasing coca cultivation, a move that would inevitably cause greater health and environmental damage to Colombia. Glyphosate is one of the most widely used agricultural herbicides in the world. It has been tested widely in the United States, Colombia, and elsewhere in the world. The U.S. Environmental Protection Agency (EPA) approved glyphosate for general use in 1974 and recertified it in September 1993. It is approved by EPA for use on cropland on which numerous crops are grown, forests, residential areas, and around aquatic areas. EPA has also established maximum residue limits (tolerances) of glyphosate in numerous food crops for human consumption. In the United States. 15-30 million pounds were used on 15-25 million acres annually in the 1990s; in 1997, approximately 51 million pounds were used. Glyphosate has been one of the top five pesticides, including herbicides, used in the U.S.

Glyphosate is used widely for many legal agricultural purposes in Colombia, including for weed control in fruit orchards and coffee plantations; for treating pre-seeded fields of rice, cotton, corn, sorghum, barley, and soybeans; and as a maturing agent for the production of sugar cane. Only ten percent of all the glyphosate used in Colombia is for coca eradication. In EPA's last comprehensive review of scientific studies on glyphosate, it concluded that proper use of glyphosate will not cause adverse effects in humans. Based on adequate scientific studies, glyphosate does not cause risks of concern for birth defects. mutagenic effects, neurotoxic effects, reproductive problems, or cancer. In June 1991, EPA classified glyphosate as non-carcinogenic for humans. based on adequate cancer studies.

Human dietary exposures and risks are minimal. Exposure to workers wearing standard protective equipment is not expected to pose undue risks due to glyphosate's low acute toxicity; however, splashes of the product can cause transient irritation to skin and eyes. "Maibach (1986) evaluated [glyphosate] and commonly used household products (Johnson & Johnson baby shampoo. Ivory dishwashing detergent. and Pinesol liquid cleaner) for acute irritation, cumulative irritation, and photoirritation, as well as allergic and photoallergic activity... The authors concluded that [glyphosate] herbicide and the baby shampoo had less irritant potential than either the cleaner or dishwashing detergent. There was no difference between [glyphosate] and the baby shampoo in terms of irritation potential."1

Glyphosate bonds tightly with the soil before breaking down and is thus unlikely to leach through the soil to contaminate underground drinking water. It is one of the herbicides that EPA has approved for controlling weeds in aquatic environments. "The toxicity of glyphosate has been evaluated in combination with several surfactants and/or other herbicides in acute studies with rats and aquatic species. Based on the results of these studies, it is concluded that the simultaneous exposure of glyphosate and other materials does not produce a synergistic response."2 Glyphosate is not persistent in soil. It does not build up after repeated use and it is biologically degraded over time by soil microbes. Fields treated with glyphosate can be replanted immediately.

The coca spray mixture consists of water, glyphosate and the inert ingredients in the formulated product. and two other products also approved for use by the Colombian government--COSMO FLUX-411F and COSMO-IN-D--to facilitate spraying. The two products are added along with the glyphosate formulated product and with water to complete the tank mixture for the spray solution. COSMO FLUX-411F is a surfactant. It increases the herbicide penetration through the waxy layer of the coca leaf by allowing more of the spray to stick to the plant. When more of the spray solution sticks to the plant, the herbicide becomes more effective which means it can be applied in smaller doses. COSMO-IN-D is an anti-foaming additive. It is used to minimize the foam created by the mixture-circulating pump inside the aircraft spray hopper. Without it, a vacuum could occur within the spray pressure pump, causing the spray system to shut down during flight. Surfactant and anti-foaming products, such as these, are commonly used in agricultural spray operations wound the world. COSMO-IN-D and COSMO FLUX-411F are produced in Colombia and Colombia's Ministry of Health has classified them as toxicology Category IV -- lightly toxic. The EPA has determined that the ingredients in both are listed in 40 C.F.R. § 180.1001, and that they are acceptable for use on food products when the label instructions are followed.

1 Williams, C., Kroes, R., and Munro, I. (2000). Safety Evaluation and Risk Assessment of the Herbicide Roundup and Its Active Ingredients. Regulatory Toxicology and Pharmacology 31, 117-165 (2000).

2 Ibid.

 Attachment: Williams, C., Kroes, R., and Munro, I. (2000). Safety Evaluation and Risk Assessment of the Herbicide Roundup and Its Active Ingredients. Regulatory Toxicology and Pharmacology 31, 117-165 (2000).
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