Pesticide use can be part of an overall IPM strategy that includes biological controls, cultural methods, pest monitoring, and other applicable practices, as discussed in the Integrated Pest Management chapter. The judicious use of pesticides, applied by or supervised by certified and professionally licensed pesticide applicators, can be an effective tool used as part of an IPM program. Minimizing damage to turfgrass surfaces caused by pests contributes to a dense, uniform playing surface, which is also a safer playing surface.
Concern over the use of pesticides typically focuses on the potential risk to human and environmental health. However, the relative risk of pesticides is largely mitigated through governmental regulation. The products are certified and continually recertified using state-of-the- art technology to ensure safety. Storage and handling of pesticides are also subject to federal, state, and some local laws that pertain to the site selection, design, construction, and operation of facilities, and areas used for storing and handling pesticides. In addition, pesticides must be applied by certified and professionally licensed applicators (or the applications supervised by the licensed applicator) who are subject to a certification process and must be regularly recertified, further ensuring safety.
Federal Regulatory Considerations
The EPA regulates pesticides under broad authority granted by the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA). The process of registering a pesticide includes scientific, legal, and administrative procedures to ensure the product meets all scientific and regulatory requirements, as described below. Pesticides are approved for distribution, sale, and use only after all scientific and regulatory requirements are fulfilled.
Pesticide Registration and Re-Registration Process
In evaluating a pesticide registration application, the EPA assesses a wide variety of potential human health and environmental effects associated with use of the product. Scientific data must be generated to address concerns pertaining to the identity, composition, and environmental fate of each pesticide, as well as the fate of that pesticide in the environment. Tests conducted address the following:
Hazards to humans and domestic animals
Hazards to non-target organisms
Post-application exposure studies
Applicator/user exposure studies
Pesticide spray drift evaluations
The types of tests are summarized on the Data Requirements for Pesticide Registration page on the EPA website. Once testing data is received, EPA scientists perform risk assessments that evaluate the potential for:
Harm to humans, wildlife, fish, and plants, including endangered species and non-target organisms.
Contamination of surface water or groundwater from leaching, runoff, and spray drift.
Human risks ranging from short-term toxicity to long-term effects.
These health and environmental risk assessments undergo a process of peer review by scientific experts. Details on these risk assessments and evaluation processes are described on the Understanding the Science behind EPA’s Pesticide Decisions page on the EPA website.
The EPA utilizes the same process to re-register pesticides. All pesticides are reviewed and re- registered at least every 15 years to ensure that they continue to meet current FIFRA standards for registration.
FIFRA and its implementing regulations govern what must be included on pesticide labels. Pesticide product labels provide critical information about how to safely and legally handle and apply pesticides. Unlike other types of product labels, pesticide labels are enforceable and must include the statement: “It is a violation of Federal law to use this product in a manner inconsistent with its labeling.” In other words, the pesticide label is the law.
A critical function of the label is to translate the results of the scientific evaluations into a set of conditions, directions, precautions, and restrictions that ensure pesticides are used safely and effectively.
All pesticide storage areas must meet state (and local, if applicable) regulatory requirements.
Both organic and synthetic pesticides are classified based on toxicity. The toxicity of any substance (pesticide or otherwise) refers to its capacity or ability to cause injury or illness through one of four routes of exposure: dermal (skin), inhalation (lungs), oral (mouth), and eyes. Acute toxicity refers to injury from a single exposure, generally of short duration. Chronic toxicity refers to injurious effects accrued over an extended period, usually after repeated or continuous exposure.
Pesticide labels may contain a “Signal Word” that is indicative of acute toxicity. These signal words are CAUTION, WARNING, and DANGER. Certain pesticides offer such a low toxicological risk that the EPA determined that no signal word is required on the label. Examples include chlorantraniliprole (Acelepryn. Syngenta Professional Products) and indaziflam (Specticle Flo. Bayer Environmental Sciences).
Many herbicides are less toxic than common chemicals such as caffeine (found in coffee, tea and many soft drinks) and nicotine (found in tobacco products). To better understand the relative risk of pesticides, the University of Tennessee published Safety of Herbicides Compared to Other Commonly Used Chemicals. This publication provides information on the acute toxicity of herbicides used in turfgrass management to control weeds and commonly used household chemicals.
Limiting Pesticide Exposure
Personal Protective Equipment
Exposure to pesticides can largely be mitigated by practicing good work habits and using application equipment correctly. Personal protective equipment (PPE) is used to reduce applicators’ risk of pesticide exposure. Product labels provide information on PPE required to minimize exposure and first-aid information specific to the product. Examples of commonly used PPE when making a pesticide application include gloves, long sleeve shirt and pants (or similar coverall), socks, and shoes. Applicators should always read and follow the label before using a pesticide in addition to following standard safe practices. Safety Data Sheets (SDS) also provide information on appropriate PPE to wear while handling the product as formulated.
To avoid contamination, PPE should not be stored in a pesticide storage area. For more information, see the Personal Protective Equipment information on the Pesticide Environmental Stewardship website.
Re-entry Intervals (REI)
Re-entry intervals are periods of time in which entry into a pesticide-treated area is restricted. When required, these periods are listed on the pesticide label. Re-entry signs may be required by state or local laws, or facility rules. For example, public properties require posting of intended applications and signs must remain posted for at least 24 hours after the application. It is the applicator’s responsibility to keep the public off treated areas. Municipalities/schools also may post notice of intended applications on their respective websites, have a list of constituents to notify prior to treatment, and signs placed at points of entry. University Extension agents can also be consulted to determine whether state or regional REI requirements exist.
Even when not required, re-entry should not be allowed in public areas until spray treatments have dried or dust has settled. A one-hour re-entry period following pesticide applications has been shown to reduce worker and player pesticide exposure (Putnam et al., 2008; Doherty, 2017). Note, applying pesticides at night to provide a re-entry period before the following day does not effectively reduce pesticide transfer and can actually increase pesticide exposure compared with daylight applications (Putnam et al., 2008). Therefore, play should be delayed on fields in early mornings for three to four days following pesticide application, with the delay of sufficient duration to allow the leaf canopy to re-dry in the morning (Jeffries et. al., 2016).
Post-application Irrigation: Post-application irrigation is often indicated on the pesticide label. Irrigating pesticide-treated turfgrass immediately following application can move some pesticide residues from the foliage into the lower canopy, or to the thatch and soil. This practice can reduce dislodgeable foliar pesticide residues 9-fold to 30-fold compared with turfgrass that is not irrigated after pesticide application (Doherty, 2017; Jeffries et al., 2016). Post-application irrigation may be an effective way to reduce pesticide exposure and may help target some turfgrass pests (e.g., grubs, root pathogens, pre-emergent weeds). It can also delay volatilization of chemicals. However, irrigating treated turfgrass can reduce efficacy of some pesticides, particularly contact materials absorbed via foliage.
Application Equipment and Calibration
Application equipment must ensure that the pesticide reaches the intended target at the proper rate. Labels specify legal application rates and sometimes suggest the appropriate equipment for use with the product. While different kinds of application equipment are available, nearly 90% of all pesticides are formulated for spraying. The size of the equipment (tank size, boom width, etc.) should be matched to the scale of the facility, the maintenance budget, and areas of application.
To apply pesticides at the proper rate, properly calibrated application equipment is essential. These practices help mitigate environmental and human health concerns, reduce the chances of over- or under-applying pesticides, and optimize pesticide efficacy. More information and a calibration worksheet are available online in Calibration & Safety of Pesticide Application Equipment (Nedin, 2012).
Sprayer output is dependent on several variables (e.g., speed, nozzle size, pressure). Spray coverage is often reduced at greater application speeds, regardless of nozzle size. To maximize efficacy of pesticide applications, applicators should consider optimizing spray coverage with respect to spray speeds. Equipment should also be checked frequently for leaks and malfunctions and should be repaired promptly.
Various types and sizes of application equipment are readily available. The size of the application equipment (tank size, boom width, etc.) should match the scale of the target area. Larger ride-on sprayers are more efficient for large areas, while small walk-behind boom sprayers are well suited for smaller areas. Smaller boom lengths may increase the accuracy of applications, minimizing overspray on non-target areas. Newer technologies incorporating GPS allow for precision application, which can reduce pesticide usage.
Nozzle selection may be dictated by the pesticide label. As always, the label is the law and must be followed. Spray nozzle size and design affect the spray drop size, which can be an important factor influencing the potential for drift and off-target movement of pesticides. Smaller droplet sizes can improve the efficacy of some pesticides, although they are more susceptible to drift. Larger droplets are more resistant to drift, although may reduce the efficacy of some pesticides due to reduced coverage. Nozzles designed to encapsulate an air bubble within the droplet (e.g., air induction nozzles) provide a good compromise between drift reduction (larger droplet size) and coverage and efficacy (drops burst into small drops on impact). Additionally, nozzles designed with a wider spray angle (i.e., 110° versus 80°) enable booms to be set lower to the ground where they are less susceptible to drift.
Storage and handling of pesticides in their concentrated form can pose a potential risk to surface or groundwater. For this reason, facilities that store and handle these products must be properly sited, designed, constructed, and operated. These sites should facilitate the secure, dry storage of pesticides; provide safe working conditions for personnel with easy access to PPE; and provide containment of incidental spills due to normal mixing/loading practices and secondary containment of large accidental spills.
General guidelines for pesticide storage include the following:
The storage area must be secured or locked to prevent unauthorized access.
Pesticides must be stored in a separate building or, at a minimum, must be separated by a physical barrier from work areas and from food, feed, fertilizer, seed, and safety equipment.
A warning sign must be placed on the exterior of the storage area.
Pesticides must be stored in a dry, ventilated, climate-controlled area.
The pesticide storage area must be kept clean.
A supply of absorbent material sufficient enough to absorb a spill equivalent to the capacity of the largest container in storage must be kept in the storage area.
The storage area must contain only properly labeled pesticide containers that are free of leaks.
Pesticides should be stored in their original containers.
The storage area must have an appropriate fire extinguisher available.
Pesticides must be stored in an area located at least 50 feet from any water well or stored in secondary containment, or distance specified by regulation or local ordinance.
Storage areas should be located where risk to human health and the environment associated with potential spills, contaminated runoff, or fire is minimized, such as a minimum of 50 feet downhill from drinking water supplies. The location should be easily accessible to service vehicles in case of an emergency.
Walls and Doors: Storage buildings should be built to contain and resist potential fire. Interior walls should be impervious to pesticides (e.g., painted steel, aluminum, fiberglass). Doors should be lockable, steel (solid core), and set in a steel frame that opens to the outside.
Floors and Concrete Specifications: Concrete floors with impervious sealant or comparable surface should be used for pesticide storage facilities. Type I or Type II cement is suggested. Epoxy, urethane, polyester, vinyl, chlorosulfonated polyethylene, and polyurea coatings prevent corrosion of floors due to fertilizers and pesticides. Coating efficacy varies and should be selected based on types of products stored in the facility. A continuous sill should surround the floor to contain 125% of the volume of the largest container in storage.
Lights and Ventilation: Storage facilities should include enough light to clearly read pesticide labels. A ventilation system should be installed to dissipate potential chemical vapor and ensure a safe workspace. Fans should be wired to turn on with lights and displace six air changes per hour.
Pesticides should be stored in their original container with the label clearly visible. Pesticides within the storage facility should not be exposed to direct sunlight, freezing temperatures, or extreme heat. Flammable materials should be stored in fireproof containment. Separate the fungicides, insecticides, and herbicides within the storage area to prevent unintended usage. Dry pesticides should be stored separately from liquid formulations to prevent contamination in case of leakage. Place pesticide containers within chemical-resistant bins or on shelves with a raised lip to contain leaks. Food, feed, potable water, seed, and personal protective equipment should not be stored within pesticide storage areas.
Pesticides degrade over time and therefore large quantities of pesticides should not be stored for long periods. The “first in–first out” principle should be adopted, with the oldest products used first to ensure that product shelf lives are not exceeded. Computer software systems should be used to record inventory and use. Safety Data Sheets for all pesticides on hand should be kept in an easily identifiable location, outside the pesticide storage facility.
Proper cleaning of equipment helps prevent residues from reaching surface waters, groundwater, drainage pipes, or storm sewers. The residues from washing equipment include grass clippings, soil, soaps, oil, fertilizers, and pesticides. Therefore, equipment washing should be conducted under controlled conditions in an appropriate contained area with minimal risk to the environment and to prevent adverse washwater and stormwater runoff impacts. Equipment washing guidelines and restrictions should be established that reduce the potential for pollutants to reach stormwater runoff, surface water, or groundwater.
For equipment with pesticide residues, BMPs should be followed to ensure that washwater does not become a pollution source. Captured washwater can be used as a dilute pesticide per label, or it may be pumped into a rinsate storage tank for use in the next application and used as a dilute pesticide per the label.
Pesticide Container Management
Handling of empty pesticide containers must be done in accordance with label directions as well as with all federal, state, and local laws and regulations. Under the federal Resource Conservation and Recovery Act, a pesticide container is not empty until it has been properly rinsed. However, pesticide containers that have been properly rinsed can be handled and disposed of as non-hazardous solid waste. Federal law (FIFRA) and state laws require pesticide applicators to rinse all empty pesticide containers before taking other container disposal steps.
After following proper procedures (such as pressure rinsing, triple rinsing, puncturing, etc.), pesticide containers must be either recycled through an approved program or disposed of by depositing them in a licensed sanitary landfill. The Ag Container Recycling Council website lists empty pesticide container recycling programs.
Pesticide Spill Response and Containment
Accidents can happen. Advance preparation on what to do when an accident occurs is essential to mitigate potential negative impacts on human health or the environment. A spill containment kit containing absorbent materials (e.g., reusable gelling agents, cat litter, clay, soil, or sand), a garbage can, and a shovel should be available for small spills. Hydrated lime or bleach can be used to neutralize and clean surfaces where spills occur. Spill containment kits should be easily accessible within the pesticide storage area. Ensure that PPE, a first-aid kit, and eye-wash stations or eye-wash bottles are accessible outside the pesticide storage and mixing area.
A Pesticide Spill Response Plan containing actions to take and personnel to contact in the event of a spill or accident should be in place. The plan should include the following information:
Names and quantities of pesticides in inventory.
Location of property, including a map and directions (to relay over phone in emergency).
Names, addresses, and phone numbers of the designated spokesperson, sports field manager, and key employees.
Plan of facility showing pesticide storage locations, flammable materials, electrical service, water supply, fuel storage tanks, fire hydrants, storm drains, and nearby wetlands, ponds, or streams.
Location of emergency equipment supplies.
Contact information for fire, police, hospital, pesticide regulatory agency, and facility owner, and any other contact information deemed important.
Ensure that copies of the plan are located nearthe pesticide storage facility and the office and distributed to local police and fire departments. Maintain copies in English and any other language commonly used by employees. Be sure to update the information regularly for local police and fire departments.
Pesticide Record Keeping
Maintaining accurate records of pesticide-related activities (e.g., purchasing, storage, inventory, and applications) is essential. Applicators must maintain records of pesticide applications as required by law. These records must be kept for the regulated amount of time (at least two years).
Pesticide record keeping should include the following information at a minimum:
Date and time of application.
Product name and active ingredient.
EPA registration number.
Mode of action group.
Classification of pesticide used.
Rate of product per unit.
Application rate and total product used.
Total acres or volume of area treated.
Wind direction, estimated velocity, and weather conditions.
Type of application equipment used.
Applicator name and license number and/or person making the application.
Pesticide Management Best Management Practices
Risk Reduction Best Management Practices
Read and follow all label directions before making a pesticide application.
Follow all requirements for posting notice of pesticide applications when and where required.
Restrict staff and player entry to pesticide treated areas for at least one hour or until leaf surface has dried following application. In the three to four days after an application, restrict early morning activity until leaf surfaces are dry.
Limiting Pesticide Exposure Best Management Practices
In accordance with label directions, provide adequate PPE for all employees who work with pesticides (including equipment technicians who service pesticide application equipment).
Ensure that PPE is sized appropriately for each person using it.
Ensure that PPE meets rigorous testing standards and is not just the least expensive.
Store PPE where it is easily accessible but not in the pesticide storage area.
The federal Occupational Safety and Health Administration (OSHA) requires employers to fit-test workers annually who are required to wear respirators for pesticide application.
Meet requirements for OSHA 1910.134 Respiratory Protection Program.
Water-in pesticides after application, unless otherwise indicated by the pesticide label or if product efficacy will be decreased.
Application Equipment and Calibration Best Management Practices
Ensure that the spray technician is properly trained properly licensed and certified, or supervised by a licensed and certified pesticide applicator.
Minimize off-target movement of pesticides by using properly configured application equipment.
Properly calibrate all application equipment at the beginning of each season (at a minimum) and after equipment modifications.
Check equipment daily when in use.
Use recommended spray volumes for the targeted pest to maximize efficacy.
Calibration of walk-behind applicators should be conducted for each person making the application to take into consideration their walking speed and other variables.
Use wide-angle, air-induction, flat-fan nozzles to minimize spray drift to non-target areas.
Pesticide Storage Best Management Practices
Store, mix, and load pesticides away from sites that directly link to surface water or groundwater.
Whenever possible, store pesticides in a lockable concrete or metal building that is separate from other buildings.
Locate pesticide storage facilities away from other types of structures to allow fire department access.
Storage facility floors should be impervious and sealed with a chemical-resistant paint.
Floors should have a continuous sill to retain spilled materials and no drains, although a sump may be included.
Sloped ramps should be provided at the entrance to allow the use of wheeled handcarts for moving material in and out of the storage area safely.
Shelving should be made of sturdy plastic or reinforced metal.
Metal shelving should be kept painted to avoid corrosion. Wood shelving should never be used because it may absorb spilled pesticides.
Automatic exhaust fans and an emergency wash area should be provided.
Light and fan switches should be located outside the building, so that both can be turned on before employees enter the building and can be turned off after they leave the building.
Avoid temperatures less than 40°F or greater than 100°F inside the pesticide storage facility.
Personal protective equipment should be easily accessible and stored immediately outside the pesticide storage area.
Place a spill containment kit in the storage area, in the mix/load area, and on the spray equipment.
Pesticide Inventories Best Management Practices
Avoid purchasing large quantities of pesticides that require storage for greater than six months.
Adopt the “first in–first out” principle, using the oldest products first to ensure that the product shelf life does not expire.
Ensure labels are on every package and container.
Consult inventory when planning and before making purchases.
Control temperature to avoid extreme hot or cold.
Pesticide Mixing/Washing Best Management Practices
Load and mix pesticides over an impermeable surface so that spills can be collected and managed.
Mix pesticides for spray applications according to pesticide labels.
The mixing station surface should offer easy cleaning and the recovery of spilled materials.
Pump the sump dry and then clean it at the end of each day.
Liquids and sediments should be removed from the sump and the pad whenever pesticide materials are changed to an incompatible product (i.e., one that cannot be legally applied to the same site).
Apply liquids and sediments from the sump as you would a pesticide, strictly following label instructions.
Absorbents such as cat litter or sand may be used to clean up small spills and then applied as a topdressing in accordance with the label rates or disposed of as a hazardous waste.
Sweep up solid materials and use as intended.
Collect wash water (from both inside and outside the application equipment) and use it as a pesticide in accordance with the label instructions.
The rinsate may be applied as a pesticide (preferred) or stored for use as makeup water for the next compatible application.
Pesticide Container Management Best Management Practices
Rinse pesticide containers immediately in order to remove the most residue.
Rinse containers during the mixing and loading process and add rinsate water to the finished spray mix.
Rinse emptied pesticide containers by either triple rinsing or pressure rinsing.
Puncture empty, rinsed pesticide containers and dispose of them according to the label.
Best Management Practices for Spill Response and Containment
Develop a pesticide spill response plan that includes procedures to control, contain, collect, and store spilled materials.
An inventory of the pesticides kept in the storage building and the SDS for the chemicals used in the operation should be accessible on the premises, but not kept in the pesticide storage room itself.
Prominently post “Important Telephone Numbers” including CHEMTREC, for emergency information on hazards or actions to take in the event of a spill.
Ensure an adequately sized spill containment kit is readily available.
Designate a spokesperson who can speak on behalf of the facility should an emergency occur.
Host a tour for local emergency response teams (e.g., firefighters) to show them the facilities and to discuss the emergency response plan. Seek advice on ways to improve the plan.
Pesticide Record Keeping Best Management Practices
Keep and maintain records of all pesticides used to meet legal (federal, state, and local) reporting requirements.
Use electronic or hard-copy forms and software tools to properly track pesticide inventory and use.
Keep a backup set of records in a safe but separate storage area.
Develop an IPM plan and update the document annually or as needed during the season.
Assign location of the IPM plan for public record-keeping purposes and keep document up-to-date and available for public record.
Use records/assessment forms to monitor pest control efforts and to plan future management actions.