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Jim Criswell
Extension Pesticide Coordinator
Before developing a pesticide management system, a commercial pesticide applicator must consider possible side effects on his or her own body, other employees, and clients. Possible side effects include drift damage, phytotoxicity, reentry, residues, and tolerances. Personal health and the prosperity of the business depend on knowledge and care in application.
The OSU Extension manual, Applying Pesticides Correctly(E-834), addresses the acute hazards to man and other warm blooded animals that are associated with the handling of pesticides.
Hazards to Applicator, Worker, and Consumer
Dermal Toxicity
The greatest hazard from pesticides is absorption of pesticides through the skin. A survey conducted in a leading agricultural state found that more than 80 percent of the cases of poisoning in agricultural and industrial settings resulted from pesticides being absorbed through the skin. This can be caused by a splash, spill, or drift when mixing or applying the chemical, or from contact with a pesticide residue after application.
The hazard of skin absorption is increased by cuts, abrasions, scratches, scuffs, or other damage to the skin. However, absorption can occur rapidly even through healthy skin. Absorption is high and rapid through the scrotum, arm pit, ear canal, forehead, and scalp. It is slower in the palm of the hand and the ball of the foot. However, even in these lower absorption areas, penetration can be great and will vary from pesticide to pesticide. For example, carbaryl (Sevin) is thought of as a relatively safe material, but it is absorbed through the skin of the forearm about seven times more rapidly than malathion or parathion. Studies show pesticides can be absorbed within a few minutes; therefore, waiting until the job is done to wash spills or splashes on the skin may be too late.
Wash by rubbing hands together or with a piece of cloth, using detergent or soap. Do not scrub with a brush, since the outer, protective layer of skin could be scratched enough to permit more rapid absorption of any pesticide which is not removed.
Since dermal toxicity is a major concern, the EPA has specified that shoes and socks, a long-sleeved shirt, and long legged pants are the minimum personal protective equipment (PPE) required for any pesticide application.
Eyes
Eyes are particularly sensitive to harm by pesticides and should be protected with goggles or a face shield. If a pesticide is splashed into the eye, immediately flush the eye with a gentle stream of clean, running water or eye flushing solution for 15 minutes while holding the eyelid open. A few seconds delay could increase the extent of the injury. Do not use chemicals or drugs in the wash water. They may increase the injury. Convenient plastic eye wash bottles and holders are available. These useful bottles can be purchased from chemical laboratory suppliers and are called "eye wash stations." Whether using clean water or commercial solutions, these need to be changed periodically to ensure their safety and freshness.
Lungs
Many applicators are not aware that inhalation of pesticides is a serious hazard. Inhalation is next in importance to skin contact in toxicity concerns. Since the lungs have such a large and highly absorptive surface area, even small amounts of a pesticide are hazardous because they are almost completely absorbed in the lungs. Vapors and extremely fine particles, 10 microns or smaller, are particularly hazardous. Spray particles of this size can move deep into the lungs and reach the area of the lungs where the blood vessels take in oxygen. This is an extremely critical area for absorption of materials into the blood stream.
Respirators should be worn when required by the label and when the applicator deems it necessary (regardless of label requirements), such as when small spray particles may be present. Occasional use of a moderately toxic pesticides which do not require a respirator may not pose a risk. However, daily use of such pesticides could greatly increases exposure and may require use of a respirator to decrease the risk (exposure).
Feet
Foot protection is an important safety tool when using pesticides for controlling ornamental pests. During the mixing/loading, application, and sprayer cleaning processes, the feet are potentially exposed to pesticide concentrate and spray mixture. By wearing chemical-resistant footwear, potential contamination to the feet can be avoided.
When selecting boots for PPE, there are several items to consider. First, check to see that the soles of the footwear are made of a durable substance which will not wear out quickly on rough surfaces, such as concrete, asphalt, or gravel. Next, make sure the soles have skid-resistant surfaces. Some footwear is extremely slippery when used on smooth concrete or metal surfaces which are wet. Be sure the footwear can withstand the use to which they will be subjected. Also, consider the comfort of the wearer. For example, footwear that is excessively hot will not be worn by applicators. Lastly, consider the ease of putting on and removing the footwear. Remember, boots are not needed when driving between jobs or during most of the day; rather, they are needed only when exposure to pesticides may occur. Therefore, the footwear must be easily put on and removed. Otherwise, they will not be used at all.
Hands
If pesticide applicators could choose only one PPE item, it would likely be gloves.
When selecting gloves, remember that they come in different sizes and not all hands are the same size. Therefore, it is likely you will need different sizes of gloves for your business.
Make sure the gloves will not interfere with other operations which must be done when worn. If this occurs, accidents are likely to follow. Dexterity is very important when selecting gloves. If dexterity is not considered, it is likely the glove selected will not preform as desired and will not be used. Also consider the durability of the gloves. If reel hoses are being used, for example, the gloves must withstand the friction from the hose. Chemicals can easily penetrate gloves if small holes are worn in them.
When many types of pesticides are being used, experiment to see how the gloves will react with the various pesticides. Switch to another type of glove material if the gloves are observed to "bubble" or "blister," because this is a chemical reaction and the glove material is being broken down.
Do not use latex gloves. Latex gloves will not provide the required protection. Use nitrile, butylene, or similar type of glove material. Do not use cloth or leather gloves for PPE. These gloves will absorb the pesticide and they cannot be cleaned. Only use these gloves as an outer glove with PPE underneath the cloth or leather gloves. When this is done, the cloth/leather gloves must not be used for other purposes, or they should be destroyed after each job.
Liners or gloves with liners are generally more comfortable to use and easier to remove. However, if the liner becomes contaminated with the pesticide, the hand becomes contaminated. Therefore, liners should only be used when one can ensure the liner will not become contaminated with the pesticide.
When repairing spray equipment, wear chemical resistant gloves if the equipment has not been thoroughly washed.
Selection of Pesticide Protective Clothing
Selection can begin once you decide which pesticide to use and know how it affects humans. Without this information, selection is almost impossible. Once the pesticide has been selected, the label and Material Safety Data Sheet (MSDS) are to be consulted for toxicity and PPE information.
Personal Protective Equipment (PPE) Clothing
Minimum PPE clothing includes shoes and socks, longlegged pants, and a long-sleeved shirt. These items are for all pesticide handling and application activities.
PPE comes in various forms and has different degrees of protection. The simplest is "normal" work clothing. Clothing should be of a closely woven fabric. The close weave "catches" more pesticide particles in the fabric, thus keeping them from directly contacting the skin,. Generally, natural fabrics catch pesticide droplets better than synthetic fabrics. However, natural fabrics may be more difficult to clean. Natural fabrics are better at catching pesticide particles because the fibers are frayed. Multiple washings of synthetic fabrics before use will often fray the fibers, thus providing similar "catching" properties of natural fabrics. Synthetic fabrics are often somewhat water repellent which also increases their effectiveness. However, normal work clothing should be worn only when the pesticide label permits them and when small amounts of spray particles are expected to be deposited on the clothing by those pesticides. Other PPE clothing should be used if one expects to receive large amounts of spray particles on their clothing.
PPE Material
Disposable PPE clothing is either woven or spun. Woven material is made of closely woven synthetic fibers. These materials are water repellent and tightly woven, thus they greatly limit the amount of spray that reaches the body. Woven fabrics "breathe" and are relatively comfortable. These fabrics are often treated with water repellent materials. The water repellent materials increase protection, but they also decrease the fabrics's ability to breathe, making the clothing hotter and less comfortable. The other type of synthetic PPE is spun material. The fabric is extruded and does not have a weave. Since it lacks the "holes" woven materials contain, it is more protective because spray particles are much less likely to reach the skin. Spun materials are more repellant and hotter due to the decreased breathing of the fabric. There are newer fabrics with improved breathability. Treating spun materials with repellent materials will also increase its protecting ability, but it will decrease the materials breathability.
PPE Construction
It is important to know how PPE is constructed and the strong and weak points at critical areas of protective equipment.
Fabric
The choice of woven or spun fabric will partially depend on the pesticide applied. The other major consideration is comfort, which includes movement and breathability. If one is working in hot or warm conditions, the fabric's ability to breathe can become as important as the chemical protection provided. A woven fabric which has been treated with a repellent may breathe better than a spun fabric. The choice of fabrics will depend on the individual's circumstances, and may have to be determined by trial and error.Seams
Check the garment's seams. There are three types of seams. The simplest is a stitched seam. These can be effective or not, depending on the protection needed and strength of the seam. Stitching should be close (tight). Tight stitches help decrease the chance of spray particles passing through the seams. Double stitching is better than single because it adds protection and strength.Fused seams are created by fusing or welding the fabric pieces together. A fused seam provides greater protection than a stitched seam, but its decreased breathing could create a comfort concern. Most fused seams are of sufficient strength, but they should be inspected before purchasing to ensure integrity.
The third type of seam is a combination of sewn and fused. This type of seam is the most protective because it provides all the benefits of the two; however, the breathability will be decreased.
Zippers, Buttons, Velcro, Draw Strings, and Snaps
The fastening device can be very important. Buttons provide the least protection, because spray particles can pass through or around the loose closure. Velcro can provide a tighter closure; however, spray particles can build up on the velcro. Draw strings on pants can create the tight fit needed, but, like velcro, they can become contaminated over time. Metal zippers can become corroded by pesticide sprays. Plastic zippers can be dissolved if concentrated formulations are spilled on them. Zippers can form a tight or loose closure. Obviously, a tight closure is desired. One should consider the ease of operating the zipper with gloves. Snaps are similar to zippers and buttons. They have the same problems as buttons but are generally easier to fasten. Like zippers, they can be damaged by certain types of pesticide formulations. Snaps can also be damaged by being bent; thus, they can be difficult to fasten. Often, closure devices can be improved by being inset with a covering flap.
How to Select PPE Clothing
First,determine the major formulations and requirements on the pesticide label and its MSDS. Regardless of whether woven or spun material is selected, be aware of a number of items pertaining to the construction of the PPE.
Once the type of PPE is known, the applicator must take into account the various aspects of the PPE to be worn. If heat is a concern, PPE which does not "breathe" may need to be avoided and another type used.
In selecting PPE, consideration of the applicator requirements is paramount. PPE must not bind or restrict the applicators movement such that the PPE becomes a greater hazard than the pesticide. Most PPE coveralls and sleeve protectors are bulky. When working around moving parts, such as reel hoses and sprayer pulleys, care must be taken to ensure clothing does not get caught in moving equipment.
Cleaning and Disposing of PPE
Boots and gloves should be washed with soap and water before removal. Disposable coveralls which received an excessive amount of spray residue should be rinsed with clean water before removal. These actions provide safety measures for the wearer during the changing and storage process of the PPE.
Once removed, gloves should be washed again in soap and clean water and air dried in a location away from pesticides. Cloth coveralls should be washed, if possible, and air dried. When washing, use 140°F water, a full wash load cycle, and a strong detergent. Wash the clothes in a load by themselves do not wash PPE with other laundry. This helps avoid possible cross contamination of pesticide residues with other clothing. Air dry the clothes. Run another complete cycle through the washer to clean the washer drum. Disposable coveralls may be laundered according to manufacturer instructions. An applicator has to make the decision whether to launder disposable coveralls or to use them a specified number of times and then destroy them. When disposable coveralls are laundered, they lose some of their protecting ability. Any PPE which is exposed to concentrate pesticides should be rinsed and disposed.
Respirators are to be washed and dried after each day's use. They may be washed in warm water with mild soap, wiped, and hung up to air dry. Do not use alcohol on respirators. Likewise, eye protection needs to be washed in the same manner after each day's use.
When PPE items are to be disposed, shred and destroy them after cleaning so they cannot be used by someone else.
Cost of PPE
PPE costs do vary. The type and cost of PPE should be included in the selection of a pesticide.
Regulatory Matters
Reentry Into Treated Areas
Reentry requirements have been established for ornamental pesticides applications, as has been done for many agricultural pesticides. Ornamental pesticide labels do address reentry, usually by stating, "... Keep children and pets off treated areas until the sprays have dried." Some labels may provide a safe time for reentry, such as 12 or 24 hours after treatment. Such label statements are to be followed. They also must be considered when selecting a pesticide. Such requirements for pesticides to be used in parks and other high traffic areas can cause extreme management problems for the applicator.
Endangered Species Act
The Endangered Species Act (ESA) affects all federal programs and agencies. Since the EPA registers pesticides, pesticides are covered under the ESA. The act applies to all outdoor applications of pesticides.
Basically, no person is to take any action which may harm or kill a federally endangered or threatened species. This includes affecting the species habitat or food source. Ornamental pesticide applicators are responsible for determining whether or not their actions will harm an endangered species in the area to be treated. Your county Cooperative Extension agent, Extension pesticide coordinator, U.S. Fish and Wildlife Service representative, and State Department of Agriculture inspector can provide information on location of endangered or threatened species.
Water Quality
A number of federal and state regulations affect ornamental pesticide applications and water quality.
Whenever a sprayer is loaded with water and/or pesticide, there must be either a working anti-siphoning device attached to the hose or a physical air gap between the hose and the sprayer. This is to prevent backsiphoning which occurs when the hose is placed inside the sprayer and water pressure is lost, resulting in the sprayer tank contents being siphoned into the water line.
All applications of ornamental pesticides must be done in such a way as to prevent possible runoff into streams, rivers, ditches, or lakes. This is to ensure that no pesticide runoff contaminates the local surface water.
If an ornamental application is to be done on soil where the water table is high or the soil is susceptible to leaching, the applicator needs to ensure that the application does not lead to potential leaching of the pesticide into the ground water. OSU Extension fact sheet F-7461 can provide useful information on this. Also, county SCS offices have information on the depth to ground water for the soils in each county.
Worker Protection Standard
Although the EPA's Worker Protection Standard (WPS) does not include applicators treating household/urban ornamentals, it does include those making applications to greenhouse, nursery, and Christmas tree sites. We would expect many of the requirements for WPS to eventually include ornamental applicators. In that respect, applicators should carefully read the pesticide labels for PPE requirements.