Chapter 13 – Management and Application of Pesticides in the Nursery and Landscape Industry

Learning Objectives

From reading and studying this chapter, you should be able to:

• Understand better what constitutes a pesticide.
• Recognize the difference between an insecticide, herbicide, and fungicide.
• Recognize the benefits and disadvantages of commonly available formulations.
• Discuss why the pesticide label is so important.
• Understand legal obligations to follow label directions.
• Recognize the relationship between personal risk and degree of exposure.
• Know how to associate signal words with acute toxicity levels.
• Discern why correctly identifying the pests and knowing their lifecycle is so important when selecting a pesticide.
• Why looking over the application site is critical before making a pesticide application.
• Know what the consequences of putting on too much or too little product.
• Know why using 50% water before adding any pesticide product is critical in getting a good mixture.
• Understand how to reduce the likelihood of a pesticide drifting off the targeted site.
• Know the correct steps in triple-rinsing a plastic pesticide container.
• Identify driving practices that will keep you safe.
• Have a general idea of what to do in the event of a worksite or highway spill of a pesticide.

Pesticides Classified by What or How They Control

“Pesticide” is a very broad term that covers thousands of different chemicals in the same way that “medicine” is a broad term that covers a wide range of healthcare products. If you say, “I am using a pesticide,” you are saying very little about what you are using.

Pesticides are chemicals that control pests. Pesticides control weeds, plant diseases, insects, rodents, and other pests. Pesticides work by disrupting some part of the pest’s life process. For example, a pesticide might prevent an insect from reproducing, prevent a weed from performing photosynthesis, repel a rabbit, or prevent a fungal disease from infecting a plant leaf.

Each pesticide is designed to control a select group of pests, such as weeds, insects, or diseases. Insecticides control insects; herbicides control weeds; fungicides control some fungal diseases. No one pesticide will kill all types of pests. For example, a pesticide that protects your apple tree against codling moth will not control apple scab on the tree.

Pesticides are grouped and named based on what they control. This is why it is important to correctly identify the pest you are trying to control so you will choose the proper pesticide. Insecticides are not intended to kill weeds, and herbicides are not meant to kill insects. Neither prevents diseases. A single insecticide will not control all insects, nor will one fungicide control all plant diseases. Each chemical is formulated to control certain pests.

Pesticides are the preferred solution for controlling certain unwanted pests, because they can control the problem before it begins. For example, you can apply a protective spray to prevent plant diseases. There are times when you discover pest damage at such an advanced stage or when pest numbers are so high that it is too late to use alternative management strategies. In such cases, pesticides may be the only effective method left as a rescue treatment.

Pesticide Purchase Based on Formulation

There is a seemingly endless variety of pesticide products sold in the urban and agricultural marketplace. Casual observation in any hardware store or lawn and garden center will reveal that variations extend even to products that are manufactured by the same chemical company and contain the same ingredients.

Manufacturers often produce various forms of a pesticide to meet different pest control needs. For example, an insecticide may be applied as a liquid to control adult Japanese beetles on rose bushes and as a solid material for suppressing the larval (grub) stage of that insect in turf. Applying the insecticide as a liquid spray permits contact with the adult beetle, while the solid form can be watered into the root zone of the lawn where the grubs live.

A pesticide product consists of two parts: active and inert ingredients. Active ingredients are chemicals which actually control the pest. Inert ingredients are primarily solvents and carriers that help deliver the active ingredients to the target pest; they serve to enhance the utility of the product. Inert ingredients may be liquids into which the active ingredient is dissolved, chemicals that keep the product from separating or settling, and even compounds that help secure the pesticide to its target after application.

An Overview of the Formulation Process

The active ingredients in pesticide products come from many sources. Some, such as nicotine, pyrethrum, and rotenone, are extracted from plants. Others have a mineral origin, while a few are derived from microbes. However, the vast majority of active ingredients are synthesized in the laboratory. These synthetic active ingredients may have been designed by an organic chemist or discovered through a screening process of chemicals generated by various industries.

Regardless of their source, pesticide active ingredients have different solubilities. Some dissolve readily in water, others only in oils. Some active ingredients may be relatively insoluble in either water or oils. These different solubility characteristics, coupled with the intended use of the pesticide, in large measure define the types of formulations in which the active ingredient may be delivered.

Usually, an active ingredient will be combined with appropriate inert materials prior to packaging. A brief review of some basic chemistry terminology should prove helpful in understanding differences among the various types of formulations, and lead to a greater understanding and appreciation of the advantages and disadvantages of many commonly used pesticide formulations.

Sorption

In some cases, it may be necessary or desirable to adhere a liquid active ingredient onto a solid surface (e.g., a powder, dust, or granule). This process is called sorption and it can be accomplished by two possible mechanisms:

• Adsorption—a chemical/physical attraction between the active ingredient and the surface of the solid.
• Absorption—entry of the active ingredient into the pores of the solid.

Solution

A solution results when a substance (the solute) is dissolved in a liquid (the solvent). The solute can be a solid, a liquid, or a gas. The components of a true solution cannot be mechanically separated. Once mixed, a true solution does not require agitation to keep its various parts from settling. Solutions are frequently transparent, although if they are darkly colored this may not be the case.

Suspension

A suspension is a mixture of finely divided, solid particles dispersed in a liquid. The solid particles do not dissolve in the liquid, and the mixture must be agitated to maintain thorough distribution. Most suspensions will have a cloudy appearance. The herbicide AAtrex 4L is formulated as a suspension. The label directs the user to shake well before using. This product also forms a suspension when mixed with water for application as a spray. Explicit label information de- scribes the need for sufficient agitation to keep the product dispersed in the spray tank.

Emulsion

An emulsion is a mixture that occurs when one liquid is dispersed (as droplets) in another liquid. Each liquid will retain its original identity and some degree of agitation generally is required to keep the emulsion from separating. Emulsions usually will have a “milky” appearance. The insecticide Diazinon 4E is formulated as an emulsifiable concentrate. The active ingredient is dissolved in an oil-based solvent. When the product is mixed with water, an emulsion is formed. An emulsifying agent in the formulated product helps prevent the emulsion from separating by surrounding the oil droplets that contain the dissolved active ingredient to keep them from reuniting.

Pesticide Selection Considerations

The importance of formulation type is generally overlooked. A well-considered decision to use the most appropriate formulation for a given application will include an analysis of the following factors:

• Applicator safety. Different formulations present various degrees of hazard to the applicator. Some products are easily inhaled, while others readily penetrate skin, or cause injury when splashed in the eyes.
• Environmental concerns. Special precautions need to be taken with formulations that are prone to drift in air or move off target into water. Wildlife can also be affected to varying degrees by different formulations. Birds may be attracted by granules, and fish or aquatic invertebrates can prove especially sensitive to specific pesticide formulations such as 2,4-D esters.
• Pest biology. The growth habits and survival strategies of a pest will often determine what formulation provides optimum contact between the active ingredient and the pest.
• Available application equipment. Some pesticide formulations require specialized application equipment. This includes safety equipment, spill control equipment and, in special cases, containment structures.
• Surfaces to be protected. Applicators must be aware that certain formulations can stain fabrics, discolor linoleum, dissolve plastic, or burn foliage.
• Cost. Product prices may vary substantially, based on the ingredients used and the complexity of delivering active ingredients in specific formulations.

Common Pesticide Formulations

Formulations are classified as solids or liquids on the basis of their physical state in the container at the time of purchase. A formulation can contain more than one active ingredient, and many have to be further diluted with an appropriate carrier (e.g., water) prior to use.

Solid Formulations

Solid formulations can be divided into two types: ready-to-use, and concentrates which must be mixed with water to be applied as a spray. The properties of five solid formulations are de- scribed in this chapter. Two of the solid formulations (granules, and pellets) are ready-to- use, and three (wettable powders, dry flowables, and soluble powders) are intended to be mixed with water.

Granules

The manufacture of granular formulations is similar to that of dusts except that the active ingredient is sorbed onto a larger particle. The inert solid may be clay, sand, or ground plant materials. A granule is defined by size: Granule- sized products will pass through a 4-mesh (number of wires per inch) sieve and be retained on an 80-mesh sieve. Granules are applied dry and usually are intended for soil applications where they have the advantage of weight to carry them through foliage to the ground below. The large particle size of granules minimizes the potential for drift. There is also a reduced inhalation hazard, but fines are associated with the formulation— especially when a bag is being emptied. In addition, granules have a low dermal hazard. The primary drawbacks of granules are their bulk, the problems they present in handling, and the difficulty inherent in achieving a uniform application with this type of product. Granules also may have to be incorporated into the soil to work, and they are sometimes attractive to nontarget organisms such as birds.

Pellets

Pellets are very similar to granules, but their manufacture is different. The active ingredient is combined with inert materials to form a slurry (a thick liquid mixture). This slurry is then extruded under pressure through a die and cut at desired lengths to produce a particle that is relatively uniform in size and shape. Pellets are typically used in spot applications. Pelleted formulations provide a high degree of safety to the applicator. They do have the potential to roll on steep or frozen slopes and thereby harm nontarget vegetation or contaminate surface water.

Wettable Powders

Wettable powders are finely divided solids, typically mineral clays, to which an active ingredient is sorbed. This formulation is diluted with water and applied as a liquid spray. Upon dilution, a suspension is formed in the spray tank. Wettable powders are a very common type of formulation. They provide an ideal way to apply an active ingredient in spray form that is not readily soluble in water. Wettable powders tend to pose a lower dermal hazard in comparison to liquid formulations, and they do not burn vegetation as readily as many oil-based formulations. This formulation does present an inhalation hazard to the applicator during mixing and loading because of the powdery nature of the particles. Furthermore, there are a series of disadvantages associated with all formulations that form a suspension in the spray tank: They require agitation to prevent settling out; they can be abrasive to equipment; and they may cause strainers and screens to plug.

Dry Flowables

Dry flowables—or water dispersible granules, as they are sometimes called—are manufactured in the same way as wettable powders except that the powder is aggregated into granular particles. They are diluted with water and applied in a spray exactly as if they were a wettable powder. Dry flowables, as would be expected, form a suspension in the spray tank; they have basically the same advantages and disadvantages as wettable powders, with several important exceptions. During the mixing and loading process, dry flowables pour more easily from the container and, because of their larger particle size, reduce inhalation hazard to the applicator.

Soluble Powders

Soluble powders, although not particularly common, are worth mentioning for purposes of contrast with the wettable powders and dry flowables. Their lack of availability is due to the fact that not many solid active ingredients are soluble in water. Those that do exist and are formulated in this fashion are mixed with water prior to spraying, dissolve in the spray tank, and form a true solution. Soluble powders provide most of the same benefits as wettable powders without the need for agitation once dissolved in the tank. They are also nonabrasive to application equipment. Soluble powders, like any finely divided particle, can present an inhalation hazard to applicators during mixing and loading.

Liquid Formulations

Descriptions of four, common liquid formulations that are normally mixed with water.

Liquid Flowables

The manufacture of liquid flowables (or flowables) mirrors that of wettable powders— with the additional step of mixing the powder, dispersing agents, wetting agents, etc., with water before packaging. The result is a suspension that is further diluted with water before use. The product is applied as a spray with all the advantages of a wettable powder. The benefit of this formulation is that there is no inhalation hazard to the applicator during mixing and loading since the powder already is suspended in water, permitting it to be poured. Liquid flowables form a suspension in the spray tank and have the same problems inherent in any suspension. However, they usually do not require agitation during application due to the extremely small size of the suspended particle but will settle if not tended to. One further problem noted with this formulation is the difficulty in removing all of the product from the container during mixing, loading, and container rinsing.

Microencapsulates

Microencapsulates consist of a solid or liquid inert (containing an active ingredient) surrounded by a plastic or starch coating. The resulting capsules can be aggregated to form dispersible granules (see dry flowables), or they can be suspended in water and the product sold as a liquid formulation. Encapsulation enhances applicator safety while providing timed release of the active ingredient. Liquid forms of microencapsulates are further diluted with water and applied as sprays. They form suspensions in the spray tank and have many of the same properties as liquid flowables.

Emulsifiable Concentrates

Emulsifiable concentrates consist of an oil- soluble active ingredient dissolved in an appropriate oil-based solvent to which is added an emulsifying agent. Emulsifiable concentrates are mixed with water and applied as a spray. As their name implies, they form an emulsion in the spray tank. The emulsifying agents are long-chain chemicals that orient themselves around the droplets of oil and bind the oil-water surfaces together to prevent the oil and water from separating. Emulsifiable concentrates allow oil- soluble active ingredients to be sprayed in water as a carrier. Some agitation is typically required to maintain dispersion of the oil droplets. They are not abrasive to application equipment, nor do they plug screens and strainers. Emulsifiable concentrates have several disadvantages. There is a dermal hazard associated with this formulation. Emulsifiable concentrates readily penetrate oily barriers like human skin. They usually have an odor problem, and can also burn foliage and cause the deterioration of rubber and plastic equipment parts.

Solutions

Solutions (water-soluble concentrates) consist of water-soluble active ingredients dissolved in water for sale to the applicator for further dilution prior to field application. They will, obviously, form a true solution in the spray tank and require no agitation after they are thoroughly dissolved. Solutions are not abrasive to equipment and will not plug strainers and screens. Many herbicides with wide-scale use are formulated in this way including products containing glyphosate and 2,4-D. Aside from lack of availability, solutions have few disadvantages; however, some that are produced as dissolved salts can be caustic to human skin.

The Label Directs Safe, Effective, and Legal Use

The pesticide label includes all of the written information on the pesticide package. It includes the front label and often extensive information on the back of the package.

The label tells you how to use the product:

• Safely, so you do not hurt people, children, and pets and do not damage the environment or the plants you are trying to protect.
• Effectively, so that you control the pest and protect property and landscape plants.
•  Legally, because labels aren’t just guides, they are the law!

Figure 1. All pesticide labels will provide a statement to the applicator dealing with personal protective equipment that needs to be worn and steps to protect the environment and wildlife.

With few exceptions federal law requires pesticides to be registered (licensed) with the U.S. Environmental Protection Agency (EPA) before they can be sold. The EPA must ensure that the pesticide, when applied according to label instructions, can be used with a reasonable certainty that it will not harm human health and will not pose unreasonable risks to the environment. Using pesticide products comes with important responsibilities.

Pesticides available to applicators are safe if handled, stored, used, and disposed of them properly. A pesticide label includes the safe, legal, and appropriate ways to use a product. A label describes the necessary information about safety, pesticide mixing and handling, storage, spill cleanup, proper disposal, and first aid.

Pesticide labels are written to provide the most benefit with the least amount of risk to people, pets, and wildlife. Why is it so important to follow the directions on the label? Bad things can happen if you don’t read and follow label instructions:

• You might use the wrong pesticide concentration and harm your plants.
• You might fail to wear appropriate protective clothing and expose yourself to the pesticide.
• You might use a pesticide that won’t control the pest (it is not listed on the label) or use it at the wrong time. Consequently, the pesticide doesn’t control the pest and it will continue to injure your plants.
• You might accidentally kill beneficial organisms like bees needed for pollination or praying mantises that feed on pest insects.
• You might use the pesticide in a way that injures people, pets, wildlife, or the environment.
• You might drift on a vegetable garden and then find out the product is not labeled for use on vegetables. You will have to discard the produce because the vegetables may have unwanted pesticide residue that has not been evaluated for human consumption.

Only by reading (and then following) the directions on the label will you be able to use the product to protect your plants against pests in a way that safeguards yourself, owners of the property, their neighbors, and surrounding environment. Don’t use any pesticide if you are unwilling to read the label.

‘The Label is the Law’ — More Than a Catchy Phrase

Labels aren’t just guides; they are the law! The first sentence on every pesticide label in the Directions for Use section makes the label a legal document: “It is a violation of federal law to use this product in a manner inconsistent with the labeling.” The law requires pesticide users to follow all instructions on the label including application methods and rates, storage, and container disposal.

Figure 2. No one wants to end up in court defending a pesticide misuse claim.

Each state has an agency with people trained to investigate the misuse of pesticide products. In Indiana, the Office of Indiana State Chemist investigates pesticide misuse. If you fail to follow pesticide label directions, state agencies can fine you for misusing or misapplying the pesticide.

In some cases, not following label directions can lead to lawsuits when the product you used allegedly injured a person or damaged their property. Everyone who uses a pesticide should read the label thoroughly before any application and follow label instructions when applying the pesticide.

Organization of the Pesticide Label

Becoming familiar with pesticide label content and design is crucial to selecting the most appropriate pesticide products and receiving maximum benefit from their use. While label information may seem overwhelming at first, it takes only a few minutes to understand the entire contents once the general format has been mastered.

FIFRA mandates that every pesticide product bear a label that clearly shows the

• brand name
• name and address of the registrant
• net contents
• product registration number
• establishment number
• ingredient statement
• warning or precautionary statements
• use classification
• signal words
• use directions

Information contained on most labels can be divided into four major categories: safety information, environmental information, product information, and use information. Thus, before selecting a pesticide product, the potential user should become familiar with the product label.

Labels change! Do not attempt to memorize the pesticide label. Reading the label each time you select and use a pesticide product allows you to recognize changes and achieve effective control while protecting yourself, others, and the environment from the consequences of misuse.

Safety Information

Child Hazard Warning

The front panel of every pesticide product label must bear the statement, “Keep Out Of Reach Of Children.” The EPA may waive this requirement only in cases where the likelihood of contact with children is extremely remote, or when the product is approved for use on children.

Signal Word

A signal word must appear prominently on the front of the pesticide container, providing, in essence, a one-word summary of the product’s potential toxicity to humans. The three signal words, in decreasing order of toxicity, are DANGER (highly toxic), WARNING (moderately toxic), and CAUTION (slightly toxic). There are newer products coming into the marketplace that will no longer carry a signal word based on their toxicological profile.

A product’s signal word is assigned on the basis of laboratory tests conducted on that particular product Data are compiled from animal studies on exposure through ingestion, inhalation, and dermal (skin and eye) absorption; and the route of exposure which shows the highest human toxicity potential determines the signal word assigned to the label. For example, if laboratory test results indicate Product XYZ to be moderately toxic if ingested, highly toxic if inhaled, and slightly toxic if absorbed through the skin or eyes, the signal word would be danger based on inhalation studies.

Hazards to Humans and Domestic Animals

Precautionary statements indicating specific hazards, routes of exposure, and precautions to be taken to avoid human and animal injury are required on the label. Example: “Harmful if swallowed, inhaled, or absorbed through the skin.” Precautionary warnings might include the language, “Do not breathe vapors or spray mist”; “Avoid contact with eyes, skin or clothing”; or “Handle concentrate in a ventilated area.”

You cannot change the acute toxicity of a product. However, adherence to precautionary warnings and protective clothing and equipment statements will minimize exposure.

The protective clothing and equipment statement directs the applicator to reduce the potential for exposure by using protective clothing or equipment. Most pesticide labels contain very specific instructions concerning the type of clothing that must be worn during the handling and mixing processes.

Potential routes of exposure determine the types of protective clothing designated on the label. Generally, a long-sleeved shirt, long pants, and waterproof footwear are the minimum requirements. The label will state whether specific items such as respirators and chemical-resistant gloves, aprons, goggles, and boots are needed.

Statement of Practical Treatment

The Statement of practical treatment (first aid) provides valuable information to persons at the scene of a pesticide poisoning. Some examples: “In case of contact with skin, wash immediately with plenty of soap and water”; “If swallowed, call a physician or poison control center immediately”; “Immediately wash eyes with water for at least 15 minutes and get medical attention”; “After first aid is given, take victim to clinic or hospital”; or “If inhaled, removed victim to fresh air.”

The statement of practical treatment informs physicians and emergency responders of appropriate medical procedures for poisoning victims. For example, the statement might indicate to a physician: “There is no specific antidote”; “If the product is ingested, induce emesis or stomach lavage”; or “The use of an aqueous slurry of activated charcoal may be considered.” Products labeled DANGER also bear 800-number physicians may call for further treatment advice. Emergency telephone numbers are provided on the Material Safety Data Sheet (MSDS). The pesticide distributor or manufacturer should be contacted for the MSDS.

Environmental Information

Environmental hazard statements are required to state the nature of potential hazards and appropriate precautions to avoid accident, injury, or damage if the product presents risks to nontarget organisms or the environment. Potential hazards are determined by a series of tests which evaluate a pesticide’s toxicity to wildlife such as mammals, fish, birds, aquatic invertebrates, and pollinating insects.

Statements might include label language such as, “This product is highly toxic to bees,” or “This product is highly toxic to fish,” or “…toxic to aquatic invertebrates.” To reduce the risks, the label may direct measures such as, “Do not allow drift to contact nontarget plants,” or “Do not apply directly to water or wetlands.”

If the pesticide has the potential to harm an endangered or threatened species or its habitat, statements will indicate where not to apply the pesticide or refer the user to an endangered species bulletin for further information. For example, the label might read “Use of this product in a manner inconsistent with the Pesticide Use Bulletin for Protection of Endangered Species is a violation of federal law,” “Restrictions for the protection of endangered species apply to this product,” or “If restrictions apply to the area in which this product is to be used, you must obtain the Pesticide Use Bulletin for Protection of Endangered Species for that county.”

Statements on environmental impact may indicate that the product “…may travel through soil and can enter ground water,” or “…has been found in ground water.” The label instructions will tell how to reduce the impact on the environment: “This product may not be mixed, loaded, or used within 50 feet of all wells, including abandoned wells, drainage wells, and sink holes’; or “This product has been shown to leach under certain conditions. Do not apply to sand and loamy sand soils where the water table (ground water) is close to the surface.”

Product Information

The brand (trade) name under which a pesticide product is sold always appears on the front panel and often is the most conspicuous part of the label.

The name and address of the producer, registrant, or person for whom the product was produced must be shown on the label. If the registrant’s name appears on the label and the registrant is not the producer, it must be qualified by appropriate wording such as “Packed for…” “Distributed by…” or “Sold by….” The net weight or volume of the contents of the formulated pesticide product is displayed prominently on the label or stamped on the container.

 

The product registration number appears on the label, preceded by the phrase “EPA Registration No.” or “EPA Reg. No.” The registration number identifies a specific pesticide product and signifies that federal registration requirements have been met. At a minimum, registration numbers consist of two sets of digits: e.g., 491-005. The first set of digits identifies the registrant. The second set represents the specific registration issued to the company by EPA. Together, these numbers clearly identify the product.

The establishment number is preceded by the phrase “EPA Est.” EPA requires pesticide production sites to be registered with EPA. A pesticide-producing establishment is assigned an EPA establishment number that clearly identifies that location. All pesticides produced at that location must bear its EPA establishment number on the label or container. Farm service centers which repackage bulk pesticides must be registered as pesticide-producing establishments; and, like all pesticide producers, they must keep records of their pesticide production and file annual production reports.

The ingredient statement normally is found on the front panel of the label. It identifies the name and percentage of a pesticide product that affects the target pest. Chemical names often are complex; for example, 2-chloro-4-ethylamino-6- isopropylamino-s-triazine is the active ingredient in the product AAtrex. To aid communication, EPA-approved common names may be substituted for chemical names. Inert ingredients allow active ingredients to be formulated into many different products. As part of the formulation, they determine a product’s handling properties and influence toxicity, release rates, residual activity, persistence, and methods of application. Also, there are no pest controlling claims for inert ingredients; and, because product formulations are confidential, the total percent by weight of inert ingredients usually is the only information about inert ingredients found on the label.

The formulation of the product often appears on the front panel of the label, either near the brand name or in the general information section. Pesticides may be formulated into many products; currently, in the United States, some 450 active ingredients are formulated into 25,000 different products. Information about the type of product formulation—granular, liquid flowable, dry flowable, microencapsulated, emulsifiable concentrate, etc.—provides insight about application equipment, handling properties, and performance characteristics.

General-use versus restricted-use classification. EPA may classify a certain pesticide product for restricted use due to the complexity of the designated use, concerns about environmental safety, or potential human toxicities. A restricted- use product may be bought and used only by a certified applicator or persons under the direct supervision of a certified applicator. A restricted- use statement appears conspicuously at the top of the front panel of the label to make oversight unlikely. All restricted-use pesticides are identified by the following language: “For retail sale to and use only by certified applicators or persons under their direct supervision, and only for those uses covered by the certified applicator’s certification.”

Pesticides which remain unclassified are referred to as general-use pesticides and may be purchased by the general public; most pesticides used by homeowners are general-use products. It should be noted that there is no such thing as a general-use statement; no general use statement ever will appear on the product label.

The physical and chemical hazard statements identify a given pesticide’s flammability or explosiveness. These statements show specific hazards and state conditions to be avoided. Examples: “Extremely Flammable”; “Contents Under Pressure”; “Keep away from fire, sparks, and heated surfaces”; “Do not puncture or incinerate containers”; “Exposure to temperatures above 130° F may cause bursting.”

The warranty information is the manufacturer’s assurance that the product conforms to the chemical description on the label and that it is fit for labeled purposes if used according to directions under normal conditions. The warranty does not extend to any use of the product contrary to label instructions, nor does it apply under abnormal conditions such as drought, tornadoes, hurricanes, or excessive rainfall.

Use Information

“Use” means more than just the application of the pesticide. Federal and state regulations define pesticide use to include handling, mixing, loading, storage, transportation, and disposal, as well as human and environmental exposure. This all- encompassing definition covers every activity that involves a pesticide—from purchase to container disposal.

Storage and transportation statements may include the following: “Store at temperatures above 32° F;” “Do not contaminate feed, food- stuffs or drinking water”; “Do not store next to feed or food, or transport in or on vehicles containing foodstuffs or feed”; or “For help with any spill, leak fire or exposure involving this material, call Chem Trek (800-424-9300). Directions for use often comprise the bulk of a pesticide label. They must be adequate to protect the public from fraud and personal injury and to prevent unreasonable adverse effects on the environment.

Agriculture Use

Directions for use may appear on any portion of the label. Because of the detail required for specific applications, use directions for common sites, pests, and applications may be grouped together under a general heading. Information specific to individual uses may be addressed under specific headings.

Requirements will contain the statement, “Use this product only in accordance with its labeling and with the Worker Protection Standard, 40 CFR part 170.” The standard itself will not appear on the label, so the user will be requested to obtain the standard from the EPA or the Cooperative Extension Service.

Re-entry or restricted entry statements contain reentry precautions and state a time interval during which reentry into a pesticide- treated site is not allowed. The statement indicates the length of time which must elapse after the pesticide application before individuals may enter the treated area without personal protective clothing and equipment. Examples of reentry statements include “Do not enter treated areas without protective clothing until sprays have dried,” and “Do not enter or allow worker entry into treated areas during the restricted-entry interval of 24 hours.”

Personal Safety With Pesticides

Hazard or risk as related to pesticide use must be considered separately from the toxicity of a given pesticide or pesticide product. Hazard varies according to exposure. The more the exposure, the greater the danger involved in using the pesticide. Therefore, the hazard (risk) associated with a given pesticide or pesticide product is dependent upon the toxicity of the compound and the probability of exposure. The hazards associated with pesticide use and application can be reduced by selecting products that are of low toxicity and by taking proper measures to prevent exposure. The degree of hazard associated with a pesticide product depends on the following:

• Toxicity of the active ingredient
• Concentration of the active ingredient
• Type of formulation
• Type of protective clothing worn
• Rate of application
• Frequency of application
• Method of application
• Persistence in the environment

One of the ways that hazard can be reduced is by the type of formulation. Granular formulations, as compared with dusts containing the same percentage active ingredient, result in less expo- sure for the applicator. The label, therefore, may carry the signal word CAUTION instead of WARNING. Careful reading of the label is re- quired to determine the exact nature of potential hazards and the precautions required for safe handling.

Although pesticide selection hinges on anticipated performance and cost, the risk associated with use is also very important; and because risk is relative to toxicity and exposure, two considerations are essential to proper pesticide selection: How safe (toxic) is the chemical? What will be the exposure level of the applicator?

Many complicated and competing factors affect the answers to these two questions, but choosing a pesticide with low toxicity and taking measures to lessen the potential for exposure are basic elements in minimizing risk—as are knowledge, selection, and maintenance of PPE.

Understanding Toxicity

Pesticide toxicity is something the applicator cannot change: what’s in the product, is in the product. Laboratory tests conducted by manufacturers and reviewed by the U.S. Environmental Protection Agency (EPA) determine a product’s toxicity and identify its strengths and weaknesses. Pesticide product testing also yields a toxicological profile of the active ingredient(s).

Evaluating Product Toxicity

Toxicity is the capacity of a compound to cause harm to a living organism. Some pesticides are inherently more poisonous than others. In all cases, the toxicity is dose-related. Answering the following questions may help the user in evaluating the toxicity of a pesticide.

What hazards are associated with the formulation?

Certain risks are more common in some formulations than others. For instance, dusts are easily inhaled; emulsifiable concentrates are readily absorbed through the skin; and aerosols may irritate the eyes and pose inhalation problems.

Is the product concentrated?
Pesticides in concentrated form pose a greater risk to the user than do ready-to-use (diluted) products for two reasons: 1) Any product in concentration is more toxic than a dilution of the same product; and 2) an additional step—mixing with water or other carriers—is required before application of a concentrate, thereby increasing the handler’s potential for exposure resulting from splashes or spills.

What is the signal word on a pesticide product?

The relative toxicity of a pesticide is reflected on the label by signal words: DANGER (most toxic); WARNING (moderately toxic); CAUTION (least toxic). Signal words also can reflect the toxicity of the  nonlethal effects such as skin and eye irritation.

The most vulnerable route of entry determines the signal word. For example, if product XYZ is moderately toxic when absorbed through the skin, highly toxic if inhaled, and only slightly toxic if swallowed, its signal word would be DANGER based on inhalation studies. Two pesticides labeled with the same signal word may or may not require the same PPE because that distinction is based on the most vulnerable route of entry as determined during the testing process. A pesticide with the signal word CAUTION usually will require less PPE than one carrying the signal word WARNING or DANGER. Labels of very toxic pesticides carry the signal word DANGER, accompanied by precautionary statements mandating the use of additional PPE.

Is the product classified for restricted use or general use?

A pesticide product may be classified for restricted use based on its potential effects on human health, wildlife, or the environment. Labels of restricted-use products carry specific precautions to safeguard those entities.

What are the acute effects of the pesticide?

There is a Material Safety Data Sheet (MSDS) for every pesticide product. The MSDS provides details on the effects of acute (very short-term or one-time) exposure to the pesticide, as well as information on dermal and inhalation toxicity and eye irritation.

Have chronic effects been documented?

The MSDS provides information on possible adverse health effects linked to chronic exposure (multiple exposures, over time) to the product. Information on cancer, birth defects, and other potential chronic effects, if any, is included in the MSDS.

Applicator Safety Based on Exposure

Toxicity is the first part of the hazard equation; the second part is pesticide exposure. Before injuries can occur, pesticides must enter the body through one of three routes of exposure: dermal (absorption through the skin or eyes); respiratory (inhalation through the lungs); or oral (ingestion by mouth).

Dermal

Dermal absorption is the most common route of pesticide exposure for the applicator. Contact with the concentrated product during mixing and loading presents the greatest risk of exposure. The degree of absorption depends on the properties of the pesticide, its formulation, and the parts of the body exposed. The forearms and hands are the most likely sites of pesticide accumulation during normal pesticide applications. Hands left unwashed after pesticide use can contaminate other parts of the body. Eyes also are extremely sensitive to pesticides. They are highly absorptive, and direct eye injury can occur when pesticides are accidentally splashed in the face.

Respiratory

Respiratory exposure by inhalation occurs during the handling of powders, dusts, fine sprays, and gases (fumigants). The lungs provide a point of rapid entry into the bloodstream.

Oral

Oral exposure generally results from improper storage or handling. Keep pesticides in their original containers; never transfer pesticides into bottles or food containers of any kind. This is extremely important in case of poisoning, because unmarked containers provide no instructions to medical personnel regarding pesticide class and treatment of the poisoning. Always keep pesticide containers tightly closed and out of the reach of children and animals.

Employee attitudes about personal safety and PPE for pesticide use often reflect the views of coworkers and supervisors. If pesticide safety and the use of suitable PPE are actively promoted by the upper echelon as means of avoiding overexposure, thereby protecting health and safety, employees may be more willing to com- ply. Companies that emphasize pesticide safety and consistent use of appropriate PPE are less likely to jeopardize their employees’ health and corporate profits—and less likely to face pesticide-related lawsuits and penalties for noncompliance. On-the-job training, hands-on demonstrations, work evaluations, and compliance checks by supervisors can stimulate consistent use of PPE.

The Six Keys to Effective Applications

Safe and effective pesticide applications require six equally important steps. Applicators must:

• Identify the pest correctly.
• Select the appropriate product.
• Calibrate equipment properly.
• Measure the pesticide accurately.
• Review the treatment site before and during application.
• Monitor the results.

Identify the Pest Correctly

Before you apply any pesticide, it is critical that you understand the pest’s biology and determine the current stage of its lifecycle. These factors are critical because pesticides are only effective against certain pests and sometimes against a specific stage such as larvae or adult.

Figure 3. The pests have to be correctly identified if you have any chance of controlling its spread. Knowing that this is a bagworm will allow you to explore its biology that will help uncover when are the best times to control this insect.

Select the Appropriate Product

It’s important that any product you select is labeled for use on the target site and is a good choice for the pest. Product selection can be complex and vary depending on industry recommendations, a company’s philosophy, and customer needs. These decisions can also be based on marketing tactics and pricing.

When you select which pesticide is appropriate, always consider:

• The product’s mode of action
• The timing of the application
• Your prior experience with the product
• The product’s use rates
• The product’s formulation type
• Any residual and drift effects
• The product’s safety to employees, customers, and the environment
• University and distributor recommendations
• Label flexibility
• The application equipment required

Calibrate Equipment Properly

Another key step to successful pesticide application is to calibrate the equipment. Calibration involves getting the individual application equipment components to deliver a predetermined amount of spray solution — uniformly and with minimal drift — to the target you will treat.

For liquid applications, calibration includes choosing the correct nozzle types and orifice sizes, pumps, hoses, pressures, and travel speeds. Each component supports a part of the spraying system and must be configured to deliver the proper volume and rate to the treatment site.

Review the Treatment Site Before and During Application

Being aware of the treatment site elevates the application beyond just spraying the product. Site awareness takes into account that each application site is unique. When conditions warrant (high winds, rain, soil conditions), applicators are expected to change application techniques, postpone applications, or adapt procedures to accommodate unusual features of the property — that includes a careful consideration of adjacent properties and the environment.

Figure 4. Always do a quick overview of the area being treated to adjust what you had planned to do that day. Keeping the pesticide out of water will keep fish from being killed.

Monitor the Results

Monitoring the results of any pesticide application will affirm whether it was made properly and achieved the results you expected. This follow up allows you to create a library of experiences for future reference.

Think Before, During, and After the Application

By combining your personal “book knowledge” and on-the-job experiences, you should make sure that the pesticide and application are:

• Applied correctly every time.
• Applied in a professional manner.
• Appropriate for the site and its surroundings.
• Applied safely.

When you apply the pesticide, it is time to put the information found on the label to use. Controlling the pest and doing it safely requires you to pay attention to label details throughout the process. When you apply any pesticide, be sure to pay attention to the details:

• Read the label.
• Only use the recommended amount of pesticide — more isn’t better.
• Keep children and pets inside and away from the treated area. Follow label requirements for how long to keep people and pets off the treated area which is often until sprays have dried.
• Wear the protective equipment indicated on the label to protect your skin and eyes.
• Mix only enough pesticide you need for the job.
• Keep the product on the target site.
• Protect wildlife, bees, and water by following label directions.

Do the Math

Before you apply any product (pesticide, fertilizer, or anything), you need to do the math first. Determine the size of the application area, and then calculate how much product you need to apply to just that area.

These calculations are important. You want to apply the correct amount of pesticide. Applying too much wastes money, adds unnecessary chemicals to the environment, and may damage your plants. Applying too little may not control the pest or protect your plants from damage.

Personal Protective Equipment

Pesticide labels typically include the personal protective equipment (PPE) you should wear while handling the product. At a minimum, you should always wear long pants, long-sleeve shirts, socks, and closed shoes when handling any pesticide. It is always recommended or the label may require that you wear chemical-resistant gloves and safety glasses. These simple precautions will keep the chemical off your skin and out of your eyes. Read pesticide labels to know exactly what you are required to wear.

Measuring and Mixing Pesticides

Read all product labels.

First, know what kind of formulation the product is. Some products will list their formulation types after the brand names, but many do not. If necessary, contact the manufacturer to determine the pesticide formulation type. Second, look for label information about optimal water pH, about the influence of hard water, and about the need to add adjuvants like surfactants or oils.

Shake all liquid product containers.

Make sure to shake them before you dispense them into the tank so that you thoroughly mix the active ingredient and inert ingredients together.

Fill the spray tank with 50 percent of the required water volume.

The amount of water you use when you prepare a tank mix can be critical. Think of sugar dissolving in a glass of water. Once the water is saturated, the sugar will no longer dissolve and will settle to the bottom of the glass. However, if you increase the volume of water in the glass, it will allow the extra sugar at the bottom of the glass to dissolve into the water. The same hold true for pesticides.

It is important to follow label recommendations. Typically, directions state that the tank must be half full of water before you add the first product. In addition, using less carrier volume may cause dry materials to clump or form gels. The more carrier that is available to disperse and/or dissolve products, the less likely the product will settle to the bottom of the tank or clog sprayer lines.

Start the agitation and continue through the mixing process.

You should always agitate products in the tank for a certain time before you add another product. Adding products in rapid succession may result in physical incompatibility. Remember, it takes time for some products to completely disperse or suspend.

If you add products too quickly (that is, one right after the other), you can interfere with the dispersion and mixing process. It’s also important to consider that just because a product appears to have dispersed does not mean the product has completely dissolved. Products do not dissolve and mix instantly (that is, in two minutes or less). This is especially the case when you mix in cold water (lower than 42°F).

Add remaining water.

You should continue agitation until the tank mixture appears uniform.

Keep Pesticides Where You Want Them

One of the risks of using pesticides is the potential for the product to end up on nearby nontarget plants as well as on birdbaths, bird feeders, swing sets, or other outdoor structures. Pesticides that reach nontarget areas can damage plants and expose wildlife, children, and pets to pesticides.

Figure 5. Spraying glyphosate in one area then walking across the turf. The residue on the bottom of the shoe was enough to kill the turf.

Nontarget plant problems caused by accidental herbicide exposures are the most common. Herbicides that accidentally land on food crops or ornamental plants can spot or distort leaves, reduce yield, or even kill the plants.

When pesticides travel through the air to areas where they are not wanted, it is called drift. It is called particle drift when the wind moves liquid spray droplets. Wind may move the droplets as they are applied, or irregular gusts may pick up droplets as they fall. To reduce particle drift:

• Apply pesticides when winds are calm or a slight breeze is blowing away from plants that might be injured. This is especially important when spraying for weeds in a lawn that borders a flowerbed or vegetable garden. A few labels will specify optimal wind conditions.
• Adjust equipment so droplets are large. Use low pressure to create large droplets that fall close to the end of the spray nozzle. The wind is less likely to move large droplets. However, very large drops may fall off the leaves of the plant you want to treat rather than stay on them to control the pest. Your goal is to make the drops as large as possible while keeping them on the plants you are spraying. Spray a few leaves, check to make sure the pesticide is staying on the leaves, and then adjust the nozzle to make the drops larger or smaller.
• Do not use pesticides when temperatures are high and humidity is low. Under such conditions, large droplets will evaporate as they fall, becoming small droplets that the wind can easily move. Also, at high temperatures (such as above 90° F), some pesticides can harm plants they are supposed to protect.
• Keep the application equipment close to the area you are treating. This way, there is less chance the pesticide will go where it is not wanted.

What should you do if you know pesticide droplets landed on the wrong plant? Don’t panic, but act quickly. Immediately wash the product off the leaves with plenty of water (well past the point of run-off) before the pesticide has a chance to enter the plant and cause damage. Make sure you also rinse off pesticides that land on automobiles, birdbaths, swing sets, and other outdoor structures.

Figure 6. Always wash off any pesticide residue when it lands on something you don’t want it to be on. Treat your customer’s property as if it were your own.

Removing Pesticide Residues from Containers

Product labels direct applicators to triple rinse each empty pesticide container, pour the rinse solution into the spray tank mixture, and use the product according to the label. Triple rinsing means washing out each pesticide container three times. This method reduces the potential for environmental damage by converting pesticide containers from hazardous waste to solid waste. Also, triple rinsing ensures that all of the pesticide product is incorporated into the tank mixture so that applicators get their money’s worth.

The following instructions explain how to triple rinse a container containing liquids.

• The same personal protective equipment worn while handling the pesticide concentrate during the mixing process should be worn while rinsing containers.
• The procedure for rinsing containers should begin immediately after emptying the contents into the application equipment. Allowing the residue to dry in the empty containers for even a few hours will reduce the effectiveness of the procedure. If you can’t rinse them immediately, leave the caps on the containers until you are prepared to do so. This will help prevent the pesticide from drying inside the containers.
• Pour the pesticide into your spray solution and let the container drain for an additional 30-60 seconds. This step greatly enhances your ability to remove the residue during the triple rinsing process.
• Add clean water (or other diluent specified on the label) equal to 10-25 percent of the container’s volume and secure the cap.
• Shake or roll the container so that the interior surfaces will be rinsed.
• Pour the rinsate into the spray mix and allow the container to drain for an additional 30 seconds. This completes the first cycle.
• Repeat the procedures outlined in steps 4-6. This completes the second cycle.
• Again, repeat steps 4-6. If the rinsate still appears cloudy or milky, keep repeating until the water looks clear, indicating a thorough rinse. If the pesticide is an emulsifiable concentrate (EC) or a liquid flowable (LF), multiple rinses are always advisable.
• Render all plastic and metal containers unusable by puncturing or crushing.
• The final step is to dispose of the containers in a sanitary landfill or offer them for recycling.

It is important to understand that there are three types of drains: septic, storm, and combined. Septic drains have solid covers, whereas storm and combined sewers have covers with openings to allow water in. If an open drain smells like sewage, it is a combined system; if not, it is a storm drain—and it is extremely important to know the difference.

In a storm drain, the outflow pipe protrudes from the middle to allow sediment, trash, and other objects to settle to the bottom of the catch basin; as the basin fills, the water rises and flows into the pipe. So, if the quantity of chemical that spills into a storm drain is less than the capacity of the catch basin, the spill is totally contained. The chemical can then be pumped out of the basin and applied to a site listed on the pesticide label.

If the catch basin is partially full of water prior to the spill, or if the quantity of chemical spilled is greater than the basin capacity, the spill overflows into the next catch basin and is possibly contained there. The likelihood of containment is great when catch basins receive a spill.

In the unlikely event the spill enters a septic or combined drains, the pipe runs along the bottom; thus, any pesticide that enters it comes into contact with moving water. Notify the city immediately if a pesticide spill enters the sewer system. Prompt notification may allow waste managers enough time to block the flow and prevent the pesticide from entering their biological filtering system.

Transportation Spills

Don’t panic! Exercising common sense and keeping calm will help you through the worst of spills. When there is an accident on the highway, the applicator should consider the following points. If a vehicle is involved, turn off the engine.

• If a vehicle is involved, turn off the engine. This lessens the likelihood of the vehicle moving or catching fire.
• Assess the situation. Your actions within the first 15 minutes will set the tone for what happens over the next few hours.
• Find out if anyone is injured. If so, or if fire is a threat, have someone call 911 immediately. Speak to the person loudly and directly, making sure he understands that he is responsible for making the call. Then return to handling the spill itself.
• Have someone else call company headquarters, advising them of the spill and asking that a member of management be sent to the scene.
• Do not move injured parties unless their lives are in danger. Moving them could worsen their injuries. Ask the victims their names and see if they know where they are. If they can answer these simple questions, let them know that help is on the way. If the victims are awake but seem dazed, they may be in shock. Administer first aid only if you have been trained to do so; otherwise, it is best to wait for medical help. This is a judgment call that you will have to make on the spot.
• If someone is unconscious, check for a pulse. Place your fingers on the side of the victim’s neck, or place your ear over the victim’s nose and mouth to see if he is breathing. If you cannot feel a pulse or detect that he is breathing, start CPR immediately. If you can detect a pulse, have someone stay with the victim while you continue to deal with the spill.
• Wear appropriate safety equipment. Protect yourself, first. Stop the leak at its source. It may be as simple as turning off the pump or shutting down the motor. Other times, rags can be stuffed into ruptured hoses or punctured tanks as a temporary fix. • Keep people away from the spill. Tell everyone to stand clear, and assign a few people to keep bystanders out of the area while you continue with emergency procedures.
• Contain the spill.
• Do not admit guilt, do not state that you have ample insurance, and do not indicate that your insurance will pay for remediation of any problems that result from the spill.

Be respectful to emergency responders who are called to the larger spills either at the work site or from a truck accident. As the employee in charge at the spill site, you likely will be the first to deal with police officers, firefighters, and paramedics. You should cooperate fully, answering any questions they have. Make sure to have material safety data sheets on the spilled chemical available for emergency personnel to review. Inform responders of the diluted concentration of the spilled chemical; it may be critical to their approach in managing the event.

The incident commander (usually one of the emergency responders) is in charge at the scene upon arrival. His or her job is to deal with personal injuries and to prevent environmental contamination while ensuring the safety of everyone involved. It is up to the incident commander to decide what actions to take to protect the public, and he may or may not solicit your input. You should know, however, that some incident commanders first instinct may be to wash the spilled pesticide into drains. If that is the case, you should politely ask him to reconsider, pointing out that if the pesticide is washed down a drain it is likely to contaminate surface water or the sewage treatment plant. Ask the commander to wait for a company management representative to arrive (or to be contacted by phone) before washing the pesticide away.

Do not address the media. You do not have the time—nor, perhaps, the authority—to speak with reporters. It is of utmost importance that you devote your undivided attention to managing the spill.

Your focus on the problem at hand is essential, but nevertheless you should not respond to media requests by saying, No comment. It is advisable to state that a member of management is on the way and will be glad to answer any questions. Suggest that the reporter speak to the incident commander; then excuse yourself to attend to details and walk away.

Do not admit guilt, do not state that you have ample insurance, and do not indicate that your insurance will pay for remediation of any problems that result from the spill. These topics should be addressed by management personnel—and even they cannot speak for the insurance company. Only your insurer can determine (according to policy provisions) how the situation will be handled.

Conclusion

Occasionally, pests get the upper hand despite all our efforts! In such cases, you may need to use a pesticide to bring the system back into balance before resuming a nonchemical approach to prevention and control. Pesticide use provides many benefits, but there are also risks. You must handle pesticides with caution and understanding.

Safety is the most important consideration when you use pesticides — not only for you but also to your customers, the environment, and wildlife. Pesticide labels provide the user with specific instructions for using the product to its greatest advantage. Pesticide users are obligated to store, handle, and dispose of pesticides in a responsible manner to protect nontarget areas, public safety, and the environment.

Figure 7. Working toward becoming certified as an Indiana Accredited Horticulturist is just the beginning. Over the rest of your career, you will have many classrooms and field day educational opportunities to increase your proficiency as a professional horticulturist.