P. E. S. T. Institute
(Pesticide Education Safety Training)
P.O. Box 1395
Huntington, NY 11743
(631) 421-3602

Dear Pandi:

My apology for taking so long. I trust you will find this long wait worth your while.

Here is the information we spoke of re: spray drift as taken from the "official" training manual that is used to train pesticide applicators seeking state licensure.

Manual title: Pesticide Applicator Training Manual - Core Manual, Northeast Regional Pesticide Coordinators, 1990

The above referenced material is a cooperative effort joined by Cornell University, University Rhode Island, West Virginia University, Connecticut Cooperative Extension Service, and University of Massachusetts.

CHAPTER VI - Air and Pesticides
pg. 2 states; EXCERPTED,..."Drift is the movement of spray particles or droplets away from the spray site, before they reach the target crop or ground surface. Pesticides in the air are not controllable (my emphasis) and may settle into waterways, homes, lawns, wooded area, etc. Drift must be avoided". 
Controlling drift is important for the commercial; applicator as well as the private applicator. To be effective, the pesticide must be applied precisely on target (my emphasis), at the correct rate, volume, and pressure. Drift from the target area may injure, people, pets, wildlife, and sensitive plants. Drift of herbicides can damage nearby crops, forests, or landscape plantings. Poorly timed applications can kill bees and other pollinators (i.e., Butterflies, & dragon flies which eat mosquitoes-my comments) which are working in the area. Beneficial parasites and predators that help control pests may also be killed. Drift can also be a problem in doors. Pest control operators must be aware that forced air heating systems and air conditioning units can moved sloppily applied pesticides (in doors as well -my comment).

Vapor Drift pg.
A pesticide that has vaporized (evaporated) can be carried from the treated area by air currents. The movement of pesticide vapors in the atmosphere is called vapor drift. Vapor drift, unlike spray or dust drift is related to the chemical properties of the pesticide. Unlike the drift of sprays and dusts that can sometimes be seen during an application, vapor drift is not visible. Vapor drift can be caused by vapor leakage.........................Applying these materials with vapor tight equipment is important..........Pesticide vapors inside a dwelling can also cause injury, particularly if the occupants are sensitive.

Applications of a volatile pesticide should be avoided when conditions favor volatilization, such as high temperature.

Particle Drift, pg.3
Particle drift is influenced by many factors. Particle size, nozzle design and orientation, pressure, temperature, humidity, evaporation, height of release, air velocity and movement are among several important considerations.

Particle and droplet size, pg3-4.
The smaller the particle size, the greater the potential for drift. (For comparison malathion particle size sprayed out over NYC fall of '99 was under 3 microns that particle size was smaller and less than the size of this period . - my comment). ......Small liquid droplets, especially those under 100 microns, also tend to drift more than large droplets.

Nozzle type, orientation and size, pg4. 
In terms of liquid drift control, the nozzle is probably more important than pressure. All nozzles produce a range of droplet sizes. Nozzles which produce small (fine) droplets should be avoided (my emphasis). Placement of the nozzle in the air stream, especially where airblast and aerial application equipment are concerned, also affect droplet size. Nozzles pointed across the air flow produce even smaller droplets. This is caused by wind shear. (such as helicopter pilot applying malathion while flying perpendicular to prevailing wind current direction - my comments)

Pressure, pg4.
Droplet size is influenced by pressure. Some equipment operators will correct drift by varying pressure. The higher the pressure, the smaller the droplet. With smaller droplets better coverage may be gained resulting in higher chemical performance but only at the expense of drift control..............

Height of nozzle, pg4.
Nozzles positioned too high will disperse spray over a wider area. This will also increase the likelihood of drift because spray particles must fall over a greater distance (my emphasis). The applicator must decide the desired swath by striking a balance among nozzle spray angle, pressure, and height above target.

Air movement, pg4.
Both horizontal and vertical air movement can affect drift. Unless it is calm, most pesticide applications are subject to constant air movement. In doors, heating and air conditioning systems move air and can move pesticides. Outside, unpredictable changes in this air movement can happen at any time to cause spray drift. Thus, wind direction and speed directly affect the direction, amount, and distance of drift.

Temperature and Humidity, pg4.
The rate of droplet evaporation is determined to a great degree by temperature and humidity. A droplet that evaporates before reaching the target does not control pests. (Therefore is a nontarget application, useless and unnecessary - my comment)

What can be done to avoid drift? pg 5.
* Choose nonvolatile (those that don't vaporize easily) pesticide formulations.
* Apply the largest effect droplet size.
* Use the lowest practical pressure.
* Choose the nozzle that produces large number of large particles.
* Place nozzles with the air stream and not across it.
* Apply as close as practical to the target.
* Use a drift control additive (more undisclosed chemical - my comment)
* Do not apply when wind, temperature, or humidity are unfavorable.
The careful use of pesticides is of prime concern to everyone to day. Many factors interact to influence the distance material will drift from the target area. Even when common sense and good application technology are followed, drift can still be a problem for the applicator. (what about the local residents present as well? - my comment) Label instructions must be followed (my emphasis) and strict attention (my emphasis) must be given to the control of pesticide drift.

CHAPTER VII - Safety, pg2.
Always read the label on the pesticide container before you begin to use it. Make sure that you understand everything you need to know about the pesticide ahead of time so that you are a responsible user. Carefully follow all the directions and precautionary advice on the label.

Be sure that you are prepared to deal with an emergency exposure or spill before (my emphasis) you begin using pesticides. Be prepared for emergency exposures and know their first aid proceduresfor the pesticides you use (my emphasis).......

Finally you should have a good understanding of your legal responsibilities when you or your workers handle and apply pesticides. Do not guess about this or anything else about your work. If you have questions about pesticide safety, techniques involving pesticide use and disposal, emergency situations, or your responsibilities under the law (my emphasis) call your state pesticide regulatory agency (NYS DEC - my comment) or your local Cooperative Extension agent (Cornell - my comment) before you use pesticides.

Personal Protective Equipment pg3.
The need for personal protective equipment depends mainly on the pesticide being handled ..........Personal protective equipment requirements are printed on pesticide labels. These requirements are based on the toxicity, route of exposure, and formulation of that pesticide. When working with moderately or highly toxic pesticides, wear coveralls over another layer of clothes or a chemical resistant protective suit, chemical resistant gloves, and chemical resistant footwear to prevent exposure of skin to the pesticide. If the pesticide is an eye irritant, wear goggles, shielded safety glasses, or a face shield.....Airblast application more often results in greater applicator exposure than other applicator methods, so additional precautions are advisable. Activities that deposit pesticides on the head or scrotum require protective head or body gear because these body parts absorb pesticides at a much faster rate than other body parts.

Wind increases the risk of outdoor pesticide application. When exposed to downward drift, wear a wide brimmed chemical resistant hat that protects the face and back of the neck. Consider wearing a face mask, shielded safety glasses, or goggles. Be aware that extreme heat and humidity can cause heat stroke and exhaustion. Other environmental considerations are terrain, proximity to public places and open versus closed spaces (my emphasis).

You, the pesticide applicator, make the final decision in the selection, use, and care of personal protective equipment. No one protective garment offers universal protection. Each pesticide use demands individual choices of protective equipment. Carefully read the pesticide label for protective equipment requirements and take additional precautions as indicated by the activity, environment, and your own personal needs.

Read and carefully follow the label directions each time you mix pesticides. Even if you have used a pesticide before read the label again. Pesticide labels frequently change....... Carefully choose (my emphasis) the pesticide mixing and loading area. It should be outside or in a well ventilated area away from other people, livestock, pets, and food or feed. It is best to mix and load pesticides on a concrete pad where spills are easily cleaned up. Pesticides should not be mixed in an area where a spill or overflow could get into a water supply. (like the sound at Fort Totten - my comment). Handling areas are frequently located near a pond or stream bank. In such a situation, grade the area to slope away from the water....

Equipment pg6
....always use equipment correctly and take good care of it. Before you begin using your equipment, check it thoroughly to be absolutely sure that everything is working properly. Calibrate your equipment so that you apply the exact amount of pesticide necessary. Be sure that there are no leaks n the hoses, pumps or tanks. Check for loose connections and worn spots in hoses that could leak or burst. One way to check for leaks is to operate the equipment at normal pressures with clean water before filling with pesticide mixtures. (this was not done - my comment).

Before application, make sure that the treatment area is clear of all unprotected people. Many states require that all persons in the intended treatment areas, or even in adjacent areas, be informed about pesticide applications before the pesticides are applied. This warning is referred to as "prenotification". Prenotification of a pesticide application is intended to protect others from exposure to pesticides..............
(my emphasis).

During Application pg 6.
While you are applying pesticides there are many safety precautions to follow. You are responsible for the protection of not only yourself but other people, domestic animals, and the environment as well. You cannot afford to be careless!

Not all labels will state it, but you as a pesticide applicator are required by law to prevent direct or indirect exposure of workers and other persons (my emphasis). Keep children, unauthorized persons, and pets out of the area to be sprayed and at a safe distance from sprayers, dusters, filler tanks, storage areas, and / or old pesticide containers.

Avoid Sensitive Areas
Avoid spraying near houses, schools, playgrounds, hospitals, bee hives (apiaries), lakes streams, pastures, or sensitive crops..........Plan you applications for times when people, animals, pets, and nontarget pests (such as honey bees) will not be exposed. Notify residents and beekeepers when you plan to spray in their areas and urge them to take appropriate precautions. Never spray directly into or across streams, ponds or lakes without first checking with authorities regarding appropriate procedures or necessary permits. Completerly cover or remove toys and pet dishes, as well as close all of the windows. Be sure that children and pets are not present in the area of the pesticide application...............

Avoid Drift, Runoff, and Spills pg 7.
Pesticides that fall anywhere but on the target area can injure people, crops, and the environment. Choose weather conditions, pesticides, application equipment, pressure, droplet size, formulations, and adjuvants that minimize drift and runoff hazard........

 (See also; The Standard Pesticide User's Guide [Englewood Cliffs, NJ: Prentice Hall, Inc, 1990],pg349.

 Entering a Treated Area pg 11.
Unprotected people should wait until the proper time to enter an area that has pesticide application. The entry restriction is the period of time that should pass between treatment and returning to a treatment area. Entry restrictions may be found on some pesticide labels. restricted entry intervals (REI) are one type of entry restriction. Do not allow workers, children, or other persons to reenter the sprayed area until this time has passed. When no restricted entry times are stated on the label, use good judgment in allowing people to return to treated areas or structures. Always wait at least until sprays dry, dust settles, and vapors disperse. If you must reenter an area early after spraying:




Some highly toxic pesticides (organophospates and carbamates) have legally specified entry restrictions of 24 to 48 hours. These time periods are listed on the pesticide labels. Some states have set even longer reentry times for some pesticides because of particular climatic conditions and other special hazards that exist in their areas.


Kinds of Poisoning pg 2.
Acute poisoning is the severe poisoning which occurs after exposure to a single dose of pesticide. The appearance of symptoms may be sudden and dramatic or they may be delayed.

Chronic poisoning is the poisoning which occurs as a result of repeated, small, non-lethal doses over a long period of time. Many symptoms may appear, such as nervousness, slowed reflexes, irritability, or a general decline in health.............

Medical Doctors Should Be Warned Ahead Of Time pg 2.
Many medical doctors may not be well informed as to the symptoms and treatment of pesticide poisoning. This is due to the few cases which they treat. Pesticide poisoning symptoms are similar to those of other illnesses and poisonings...............

See also NYS PESTICIDE APPLICATOR TRAINING MANUALS: (available for purchase seperately from Cornell University)

Category 3 - Ornamentals and Turf,
Category 8 -Public and Human Health, Category 5 - Aquatic Pest Control

Please circulate freely. 

Thank you, 
Steven Greenspan 



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