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Spray Drift of Pesticides


Current as of: December 1999
EPA: 735F99024

The drift of spray from pesticide applications can expose people, wildlife, and the environment to pesticide residues that can cause health and environmental effects and property damage. For these reasons and because the Environmental Protection Agency's (EPA), Office of Pesticide Programs (OPP) is responsible for regulating the use of pesticides in the United States. OPP has been actively engaged in a number of initiatives to help prevent such problems. These initiatives include broadening our understanding of the science and predictability of spray drift based on many new studies, helping pesticide applicators to reduce spray drift by improving product label use directions, and promoting education and training programs on spray drift for applicators. These initiatives are consistent with the Agency's mission of protecting human health and the environment from potential adverse effects of pesticides. When we complete our decisions on how we intend to use the new studies for our regulatory decisions and on the new wording for product labels, we plan to issue a draft Pesticide Registration (PR) Notice for public comment before making and implementing final decisions. This "Questions & Answers" publication provides the Agency's position on spray drift issues and a summary of responsibilities and activities of the Environmental Protection Agency and others.

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What Is Pesticide Spray Drift?

EPA defines pesticide spray drift as the physical movement of a pesticide through air at the time of application or soon thereafter, to any site other than that intended for application (often referred to as off target). EPA does not include in its definition the movement of pesticides to off-target sites caused by erosion, migration, volatility, or contaminated soil particles that are windblown after application, unless specifically addressed on a pesticide product label with respect to drift-control requirements.

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How Does Spray Drift Occur?

When pesticide solutions are sprayed by ground spray equipment or aircraft, droplets are produced by the nozzles of the equipment. Many of these droplets can be so small that they stay suspended in air and are carried by air currents until they contact a surface or drop to the ground. A number of factors influence drift, including weather conditions, topography, the crop or area being sprayed, application equipment and methods, and decisions by the applicator.

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What Are the Impacts of Spray Drift?

Off-target spray can affect human health and the environment. For example, spray drift can result in pesticide exposures to farmworkers, children playing outside, and wildlife and its habitat. Drift can also contaminate a home garden or another farmer's crops, causing illegal pesticide residues and/or plant damage. The proximity of individuals and sensitive sites to the pesticide application, the amounts of pesticide drift, and toxicity of the pesticide are important factors in determining the potential impacts from drift.

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How Does EPA View Off-Target Spray Drift?

EPA recognizes the importance of exposures to pesticides resulting from spray drift. There are thousands of reported complaints of off-target spray drift each year. Reports of exposures of people, plants, and animals to pesticides due to off-target drift (often referred to as "drift incidents") are an important component in the scientific evaluation and regulation of the uses of pesticides. Other routes of pesticide exposure include consuming foods and drinking water which may contain pesticide residues, applying pesticides, and contacting treated surfaces in agricultural, industrial, or residential settings. EPA considers all of these routes of exposure in regulating the use of pesticides.

When labels of pesticide products state that off-target drift is to be avoided or prohibited, our policy is straightforward: pesticide drift from the target site is to be prevented. However, we recognize that some degree of drift of spray particles will occur from nearly all applications. Nevertheless, applicators and other responsible parties must use all available application practices designed to prevent drift that will otherwise occur. In making their decisions about pesticide applications prudent and responsible applicators must consider all factors, including wind speed, direction, and other weather conditions; application equipment; the proximity of people and sensitive areas; and product label directions . A prudent and responsible applicator must refrain from application under conditions that are inconsistent with the goal of drift prevention, or are prohibited by the label requirements. EPA uses its discretion to pursue violations based on the unique facts and circumstances of each drift situation.

Pesticide applicators and others, including landowners, play a very important role in pesticide application -- deciding whether or not to apply a pesticide and if so how best to make that application. It is their responsibility to know and understand a product's use restrictions. They are responsible for complying with all other pesticide laws regarding pesticide applications and ensuring that their application equipment and techniques will produce a minimum of spray drift. EPA also expects applicators to exercise a high level of professionalism in making decisions about applications.

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How Does EPA Help Protect People and the Environment from Off-Target Spray Drift?

EPA is responsible for a number of important programs that help protect people and the environment from potential adverse effects that can be related to off-target drift from pesticide applications. These programs include restricting how pesticides are used, certification and training of applicators, and enforcement and compliance of pesticide laws.

Restricting How Pesticides are Used:

Under Federal law, EPA's Office of Pesticide Programs is responsible for evaluating pesticides and their uses to ensure that they can be used with a reasonable certainty of no harm to human health and not cause unreasonable risks to the environment when properly applied. In fulfilling these duties, we consider the potential impact of spray drift on humans and the environment in our evaluations of proposed pesticides for new registration and older, existing pesticides for reregistration.

As a part of our evaluation of a pesticide, we estimate the amounts of off-target drift and the associated potential risks to human health and the environment. Restrictions on a pesticide's application may be triggered in two ways. For new pesticides and existing pesticides undergoing reregistration, estimated deposition levels are evaluated along with the pesticide's toxicity. For existing pesticides, available information on drift incidents is also evaluated. Based on these evaluations, OPP may impose specific restrictions for a pesticide's application. Specific restrictions may include prohibiting the use of certain pesticides under certain conditions, prohibiting certain methods of application, requiring use of a foliage barrier, or requiring a buffer zone distance between the site of application and areas to be protected. In general, applicators must use all available drift prevention practices in order to prevent drift.

During the past few years OPP has received and reviewed new studies on spray drift that it required from pesticide registrants to support their product registrations. OPP has completed its review of these studies and reached conclusions about the factors that influence drift and the amounts of sprays which can drift from the application site.

OPP also collaborated under a cooperative research and development agreement with registrants and the U.S. Department of Agriculture (USDA) on the development of a model ("AgDRIFT") to predict distances of spray drift under many different conditions.

To ensure the scientific quality of the conduct of the studies, the conclusions that were drawn from these studies, and the predictive model, OPP obtained independent expert peer reviews, including the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA), Science Advisory Panel. These expert peer reviews supported the use of the model and these studies for OPP's science assessments of pesticides.

Based on these studies and reviews, OPP is now developing improved product labeling to inform applicators of requirements to control off-target spray drift. OPP plans to publish these requirements and an implementation plan in a draft notice (PR Notice) this winter and ask for public comments. Comments will be considered before publishing the final requirements in the summer of 2003.

Certifying and Training Applicators:

EPA also works with USDA and state government agencies to carry out certification and training programs for pesticide applicators. States have primary responsibility for ensuring that pesticide applicators are licensed and certified, as required by Federal and state laws, to apply pesticides in an appropriate manner. Part of the program for certification can include training about how to protect people and the environment from off-target spray drift.

Enforcing Compliance with Laws:

When individuals have complaints about off-target spray drift, they should report those complaints to their state or tribal government agency (either agriculture or environmental protection) that is responsible for enforcing the proper use of pesticides for that state or tribe. These agencies have the primary responsibility of enforcing lawful use of pesticide products by investigating complaints and, when appropriate, issuing penalties for improper use. When necessary, EPA will assist these agencies with investigations.

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What Other Activities Is EPA Participating in to Promote Awareness and Education of Spray Drift Issues?

For the past few years, EPA has been actively working together with other Federal and state agencies and tribes, pesticide and application equipment manufacturers, applicators, university scientists, and others (National Coalition on Drift Minimization) on many spray drift issues. Coalition members, including EPA, have focused attention on enhancing pesticide applicator education, application research, and regulatory initiatives to foster reductions in drift incidents.

Members of the Coalition have produced and widely disseminated training and educational materials for applicators, assisted with development of improved pesticide product label directions for drift reduction, and promoted common awareness and understanding of technical and regulatory issues regarding spray drift.

In August 2001, EPA published in the Federal Register for public comment a draft document (a draft Pesticide Registration Notice) proposing new labeling statements for controlling spray and dust drift. The document is entitled "Draft Guidance for Pesticide Registrants on New Labeling Statements for Spray and Dust Drift Mitigation." The Agency also published a companion document in the Federal Register providing further explanation for this guidance document. The comment period, originally scheduled to end on November 20, 2001, was extended to March 31, 2002. Based on the numerous and diverse comments submitted, the Agency is planning to hold public meetings in the future to ensure that it has received input from all interested parties and fully understands all of the issues, concerns, and suggestions in this important and complex topic before proceeding. Following these meetings, the Agency plans to draft and publish another proposal in 2003 for public comment. These documents can be found at http://www.epa.gov/opppmsd1/PR_Notices/. Additional education and communication products are scheduled for future release.

Complementing these efforts in applicator education is an increasing number of training programs sponsored by industry and pesticide applicator organizations. Such programs are designed to raise the level of professionalism and education about drift issues for those involved in pesticide applications.

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Where Can Complaints About Spray Drift Be Directed?

If you believe that you have been exposed to pesticide spray drift and have health-related questions, you should contact your physician, local poison control center, or health department for assistance. You can also contact the National Pesticide Information Center (see below for specifics).

If you suspect that there has been an occurrence of illegal spraying, you should contact your state or tribal pesticide regulatory agency (either the department of agriculture or environmental protection).

Take this opportunity to verify that you have phone numbers for emergency medical assistance and for your state and country agencies.

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Where Is Further Information Available?

Pesticide Programs at (703) 305-5017, or visit the EPA pesticide Web site.

For information on pesticides and pesticide exposure, contact the National Pesticide Information Center (NPIC) between 6:30 a.m. and 4:30 p.m.(Pacific Time), seven days a week, at 1-800-858-7378 (toll free) or through its Web site (http://npic.orst.edu/). Exit EPA disclaimer NPIC, supported in part by EPA, provides pesticide information to any caller in the United States, Puerto Rico, or the Virgin Islands.

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