Pyrethroid label requirements tweaked again

Last year I posted a story about the new pyrethroid insecticide label requirements being sent to pesticide manufacturers by the U.S. Environmental Protection Agency. The requirements were designed in 2009 to reduce the risk of drift (wind carried contamination) and runoff (stormwater-carried contamination) of these commonly used insecticides. Since last spring, when pesticide manufacturers were officially informed of the new standards, the EPA has continued to dialog with both regulators and the pest control industry.  The results of this dialog are now out, and the final product is a big improvement, in my opinion.

The new EPA label requirements will
continue to allow pyrethroid applications
to eaves and protected sites around homes
where mosquitoes and other pests
may be resting.

At issue were applications needed to control certain overwintering insects like brown marmorated stink bug and kudzu bug, both of which aggregate on the sides and eaves of structures prior to entering the home or other building.  Under the 2009 rules, outdoor applications to the sides of structures were limited to crack and crevice applications or building foundations up to a height of three feet only.  In addition, all outdoor applications to impervious surfaces such as sidewalks, driveways, patios, porches and structural surfaces (such as windows, doors, and eaves) were to be limited to spot and crack-and-crevice applications, only.

After consultation with the National Pest Management Association (NPMA), the Association of Structural Pest Control Regulatory Officials (ASPCRO) and the State FIFRA Issues Research and Evaluation Group (an EPA advisory group also comprised of regulatory officials), the EPA agreed to make further changes to the original label requirements to allow for better control of overwintering insects.

While restrictions on insecticide applications to impervious surfaces and prior to expected rainfall have not changed, there are some big changes on applications to structures, as published in a January 10 letter to pesticide manufacturers.  The three changes are summarized as follows:

• Now applications of pyrethroids may be made to the exterior of buildings where the treated surfaces are underneath eaves, soffits, windows or doors that are protected by coverings, overhangs, awnings or other structures that protect the residues from rainfall;
• application bands up to one inch-wide may be applied to cracks or other potential pest entry points;
• and applications may be made using a coarse, low-pressure spray to portions of surfaces that are directly above bare soil, lawn, mulch or other vegetation.

The purpose of these requirements is to prevent pyrethroid pesticides from entering storm water and getting into streams, something that is most likely when pyrethroid sprays land on impervious surfaces like asphalt or concrete.

In addition to giving back to PMPs the ability to use pyrethroids against overwintering pests these new regulations should help applicators control nuisance and public health mosquitoes that frequently rest on the sides of buildings and around doorways.  This was, in my view, a potentially serious public health issue with the 2009 rules.

So what will be the big change to the way your company applies pyrethroids after the dust is all settled? The new labels will prohibit power spraying driveways and over sidewalks, garage doors and any vertical building surfaces over pavement. Assuming the manufacturers follow these guidelines closely, labels should allow low-pressure sprays to the sides of structures over vegetation or soil and in sites protected from the rain, in addition to cracks and crevices.

Congratulations to the EPA and to those regulators and NPMA experts who took the time to look for ways to keep the pyrethroid label requirements reasonable while continuing to protect the environment. This is one of those examples of how the system sometimes works in everyone's favor--except, in this case, the pests'. 

Pyrethroid labeling confusion

New FMC videos explain pyrethroid label changes.

In April I posted information on the new pyrethroid label changes being required by the U.S. Environmental Protection Agency.  While the information in my April 17th post was correct, I later (May 1) posted a comment based on additional information I received from the EPA.  In that follow-up comment I said that, according to EPA, that ALL outdoor pyrethroid applications (not just preconstruction treatments as stated in the article) would not be permitted when windspeed was over 10 mph.  The problem is that I was misinformed by my EPA source.

I shared EPA's May 1 label interpretation with Dr. Jim Fredricks at the National Pest Management Association.  He and his legislative colleague, Bob Rosenberg, followed up with EPA on this information.  In an email dated 19 June 2012, Rosenberg received a response from EPA stating that their original "response (the one I received) was not correct... the 10 mph wind restriction applies only to products labeled for preconstruction termiticide applications." [my emphasis]

To those of you who read my comment, I apologize for passing on the wrong information.  Thanks to NPMA for following up and ensuring that all of us get the correct information about pyrethroid label changes and what they mean. BTW, this is a great example of the kind of service tha the NPMA provides its membership as it looks out for the interest of the industry.

I have since removed the incorrect information from the April post's comments; however pyrethroid labels may include advisory language recommending application should be made during "calm weather when rain is not predicted for 24 hours".  This may be more difficult to gauge and document than the 10 mph requirement.

As usual, if in doubt, read the label.  If it's a pyrethroid label, be extra careful over the next few months to check every pesticide container.  During this transition period some containers will have labels that have the new language, and others will not.  While technicians are OK if they use a product with the old language, it would be a good idea to train and require all your employees to start following the tighter restrictions now.

FMC Professional Products has produced some nice new videos explaining the new pyrethroid labels. Check them out at the FMC YouTube Channel.

Pyrethroid label changes hit the streets soon

You can recognize a pyrethroid insecticide by
reading the active ingredient list.  Pyrethroid
common names end with  the suffixes "-thrin"
(such as bifenthrin) or -ate (such as esfenvalerate).

The past few years has seen a major shift in the insecticides the pest control industry uses to provide long-term, residual control of general insect pests.  In the 1990s and early 2000s, chlorpyrifos, diazinon and assorted other organophosphate (OP) and carbamate insecticides dominated much of the pest management professional and consumer pesticide markets. Passage of the 1996 Food Quality Protection Act, and a conscious effort by U.S. EPA regulators to wean the country from OPs, created a regulatory environment that favored pesticides with lower toxicity potential for human and wildlife. Indeed, a recent study by Alison Clune and colleagues from Emory University provides experimental evidence that levels of OP metabolites in human urine decreased significantly between 1999 and 2004.

This decline in OP and carbamate use in pest control opened the door for increased use of pyrethroid insecticides. For the most part, pyrethroids have proven to be good substitutes for the older insecticides; however in recent years there have been growing concerns that pyrethroids might not be as environmentally safe as originally thought. Specifically, pyrethroid residues are increasingly being found in sediment at the bottom of urban streams and rivers, where they are toxic to some aquatic insects and other invertebrates.

What this means for the average pest control technician is that there will be changes over the next few months in wording on all pyrethroid labels to minimize the risk of stormwater contamination from structural pest control.  PestWeb just published a nice summary of the new rules and timelines for implementation, and the Pyrethroid Working Group (a pesticide industry coalition) also summarized the upcoming changes and offers the opportunity to sign up for email alerts on changes to regulatory alerts on pyrethroid insecticides.

It's always important to read pesticide labels, but this change means that all PMPs should be especially alert to changes in the labels of these commonly used products.  The biggest changes will be in how pyrethroids are applied to outdoor impervious surfaces. All applications made to sidewalks, driveways, patios, porches and structural surfaces (such as windows, doors, and eaves) will be limited to spot and crack-and-crevice applications only (around windows and doorways this is defined as a spray band no more than a one-inch wide). In addition, if you are in the habit of using pyrethroid insecticides to treat sewer lids or walls for cockroaches, this type of application will be specifically prohibited.