A note on Carbaryl regulations and testing

Seth Dibblee, chemicals expert from the EPA, sent us this note on carbaryl in response to some questions that were asked in a recent conference call. Please bring any questions you have about this note to our conference call tomorrow, May 31, or contact Seth directly at dibblee.seth@epa.gov.


Please let me follow up on a question that came up during the Eco-Apple last Tuesday, May 17, during Phil Schwallier’s talk on thinning. Somebody asked whether the use of carbaryl (e.g., Sevin®XLR) would continue to be allowed on the label for thinning on apples. The short answer to that question is, “Yes, for at least the next 3-4 years, absent any new developments that would change the registration.”

And I’m sorry I can’t give an unqualified answer: I don’t anticipate anything that would compromise this use, but the truth is we never know when, for example, the courts will render an unexpected decision.

Let me provide a longer explanation, just FYI: As you may know, the periodic (every 15 years) registration review for carbaryl is just getting underway. A preliminary work plan for the review was opened to the public for review/comment back in September 2010 for 60 days, and finalized in February of this year. This work plan outlines the areas where additional testing is needed to ensure that health and environmental risks are not unreasonable.

As you also know, carbaryl is one of the major active ingredients among the n-methyl carbamate insecticides. For example, the Sevin®XLR Plus label indicates that the product inhibits the enzyme cholinesterase; it also contains in its precautionary statements that the product is harmful if swallowed, absorbed through the skin, or inhaled. The label goes on to say the product is “extremely” toxic to aquatic invertebrates and “highly” toxic to honeybees and other bees.

And carbaryl has been the subject of several petitions and lawsuits which assert that its continued use is harmful to human health or the environment. Currently, EPA is in consultation with the National Marine and Fisheries Service to determine what effect its use may have on a number of endangered species.

In any case, most of the new testing planned is oriented to its ecologic impact (its human health hazard is already better known), including its impact on pollinators. EPA is aware of how important carbaryl is for apple growers, and recognizes that there is a benefit associated with thinning the crop, which will be considered in the risk assessments.

The testing and risk assessments won’t be complete until mid-2015, and they will be made available for public review and comment before any registration decisions are proposed. And those decisions themselves will be opened for public comment before they become final on revised labels. As you can imagine, it takes several years for these decisions to be made, and longer if they are high-impact or high-profile. And should there be any proposal to cancel or restrict specific uses, there will be ample time and opportunity for growers to weigh in on their impacts.

You can follow the registration review process for carbaryl at http://www.epa.gov/oppsrrd1/registration_review/carbaryl/index.html

All that said, I don’t think (giving my own opinion now) we will lose this use for carbaryl, at least for the next several years. However, I think it’s prudent to continue evaluating less toxic compounds and methods to thin apples, especially where pollinators are concerned.

You are well aware of the attention being paid to pollinator populations these days; when thinning with carbaryl–especially when a heavy fruit set is anticipated and the practice may encroach on bloom, it’s critical to protect pollinators whenever possible. We want to avoid any excess adverse effects on pollinators that would ultimately compromise this use through the registration review process. I hope all that makes sense.

I will be happy to recap this information on our next call if you’d like. Please feel free to contact me (information below) if I can explain this further.

Seth Dibblee
Strategic Agricultural Initiative Coordinator
Pesticides Section, Chemicals Management Branch
Land and Chemicals Division (LC-8J)
U. S. EPA Region 5 – Chicago
(312) 886-5992