Pyrethroid Concerns Again

Saturday July 21, 2012


Mr Pest Control


Can you please name some other products that are similar to EcoSmart's lineup? I was told by one of their reps that because of the excessive moisture in western Washington he did not think their line was the best choice for my area.....suprised me. I also question the residual of these "greener" pesticides and prefer the cold, hard "facts" on this. I like independent studies that are not connected to the manufacturers. I am not sold on my kitchen spice rack as pesticides. With respect to the new labeling of pyrethroids, labeling now calls for no spraying in the rain or if it is going to rain. Have we now stepped into forecasting? In western WA when does it not rain?

Mr Pest Control


We'll address these as two separate issues, and I share some of your concerns. I am often asked "how long" a particular active ingredient or group of them will last and always sidestep the answer to the best of my ability. The length of residual of any active ingredient is just too variable depending on many environmental conditions - heat, moisture, pH, concentration when applied, kind of surface, exposure to UV light, sanitation issues, etc. When the "EcoSmart" product line was first introduced to our industry we were told by the manufacturer that the active ingredient (hexa-hydroxyl) would last as long as the synthetic pyrethroids do. Whether or not this is true I really do not know, but my feeling is that most of the tree oils and other Botanical insecticides should be considered as contact activity with a very short residual. I don't know that I have seen any third party studies on this either, and whether it is these plant-derived products or old synthetic standbys I tend to be skeptical of some of the claims by manufacturers. 

I am not sure why your region with perpetual rainfall should be any different that any other region of the country except for the likelihood that applying the products outdoors will likely expose them to rainfall much sooner, and thus the onset of hydrolysis that degrades the molecules or simply being washed off the surface. By the way, the brand name of EcoSmart is now aimed primarily at the retail, over-the-counter market and the professional line of their products has a name change. You will now find Univar selling them as the Essentria brand and the manufacturer, formerly Prentiss, is now named Envincio. So, look for those new labels on PestWeb. 

There is no doubt that your kitchen spice active ingredients are quite toxic, and in fact hospitals admit a great many people each year suffering from clove oil toxicity due to a fad of smoking clove oil impregnated cigarettes. "Toxic" is not a quality reserved for traditional synthetic pesticides, and plants produce some pretty dangerous stuff, much of which has been formulated into insecticides. Whether the fact that they are "natural" and from plants means that, therefore, they are less hazardous to people or to the environment is a good question, but I personally believe that being natural does not change the need to use them wisely, with PPE in place, and to limit their use as much as possible by focusing on non-chemical steps in the overall management of the pest. 

Now to the pyrethroid issue. Yes, the new labeling is found in two areas of the pyrethroid labels, and this new labeling will be on ALL pyrethroid products of ALL formulations. Within the "Environmental Hazards" section of the label you will find the statement "Applying this product in calm weather when rain is not predicted for the next 24 hours will help to ensure that wind or rain does not blow or wash pesticide off the treatment area." According to the NPMA this is a "suggestion" or guideline, not a mandatory statement that you shall not apply if rain is "predicted". Instead, under "Directions for Use" you will find the MANDATORY statement "do not make applications during rain". 

I think this is a very important distinction. Yes, it would be best for everyone and for the environment to avoid applying any insecticide that may get washed off the surface in the next 24 hours, but you are only mandated to avoid the treatment if a rainfall event is in progress. Of course, we need to be upstanding about this and if we really know that it is going to start raining shortly after we apply the product it would just not be right to go ahead and spray it, even though the rain is not occurring yet and technically we are legal. Even though this statement now appears on all pyrethroid labels you will also find similar wording on the labels of many alternative products. Applying the insecticide just to see it washed away is not good for the environment and is a dis-service to the customer. 

Mr. Pest Control

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Please note, Mr. Pest Control is answering questions supplied by PMP customers across North America. His answers are generated from industry and manufacturer-provided information. The answer may not be specific to the laws and regulations for your State, Province, Territory or Country. In addition, products mentioned may not be registered and or available in all areas. Always check with your local Univar office for specific information to your area. Always read and follow label directions.