QUESTION:
When doing a “spot” treatment how large can the “spot” be? How much area needs to be left between “spots”?
ANSWER:
This is a darned good question and one that I do not have the complete answer for. So, before I launch into my discussion of it I will do what I so often do and suggest that you speak directly with YOUR regulatory agency for your state and get their opinion. Since they are the ones who oversee what you do in your state, and would be the ones to agree or disagree with your decision, it is important to know what they expect of you ahead of time. With the new labeling on all pyrethroid products this once again comes to light as important, although “spot treatment” has always been on product labels for many of their uses.
That being said, the EPA does clearly define what a “spot” is, and we can find this in some of their literature as well as on some product Labels. A spot is an area no larger than 2 square feet. Period, end of definition. So, a single spot could be 1 foot wide by 2 feet long, or 4 inches wide by 6 feet long, or a circle 19 inches in diameter, or any other combination of dimensions that add up to 288 square inches. This is a pretty broad definition, but that seems to be all the EPA has to say about it. Directly out of FIFRA here is what EPA says:
“Spot treatment is application to limited areas on which insects are likely to occur, but which will not be in contact with food or utensils and will not ordinarily be contacted by workers. These areas may occur on floors, walls, and bases or undersides of equipment. For this purpose a “spot” will not exceed 2 square feet”.
The question of how close together these spots can be is the hard one to define. For many years I have taught in seminars that the overall surface you treat with “spots” can have no more than 20% of the surface area covered. Then one day I decided to find this in some regulations somewhere, preferably in FIFRA from EPA, and by golly I could not, and still cannot, come up with it. I spoke with my own state’s regulatory agency and asked where in their laws a “spot” was defined with regard to the overall area and it appears not to be in our laws. I have seen on at least one product Label, and I do not remember now which product that was, the statement that spots cannot cover more than 15% of the overall surface area. Obviously this contradicts what I had been preaching, and since it is on that specific label then you MUST adhere to that guideline when using that product. But, there simply appears to be no further legal definition of spot treatment beyond what I show above.
So, does this mean we can be sneaky and treat a 2 square foot area, stop spraying a moment, and then spray another 2 square foot area immediately adjacent to the first one, and so on? No, I really don’t think we ought to start that. Logic and common sense tell us that the INTENT of the definition is to limit the treatment to spots that are separated by some reasonable distance, and since 20% has stuck in my mind for all these many years perhaps that would be a reasonable guideline to use until someone in authority tells you different.
View past Ask Mr. Pest Control questions.
Pest QuestionsFebruary 06, 2012