Due to toxicity and potential environmental hazard, the Environmental Protection Agency has announced its intention to revoke all tolerances for carbofuran. Carbofuran is the active ingredient of Furadan 4F insecticide, most commonly used in Iowa as a liquid formulation applied to corn. 

The Agency's announcement is in the Federal Registry. Here's a timeline for the process of Furadan leaving the market (as provided by FMC - maker of the product):

May 15, 2009: EPA issued the final rule to revoke all carbofuran tolerances. The tolerances will be revoked on December 31, 2009.

August 13, 2009:  EPA is required by regulation to open a 60 day period after the publication date of the final rule, and prior to making the rule effective, to allow interested parties to file objections to the rule, request a hearing with an administrative law judge, or request a stay postponing the effective date of the rule. So, 5/15 is the publication date and 60 days after the publication date (8/13) the rule will become effective. FMC will file its objections prior to the conclusion of the 60 day period.

December 31, 2009: The date when tolerances will be revoked as indicated in the final rule.

The announcement of the EPA's intended actions was followed with a public announcement from Iowa Secretary of Agriculture Northey to increase Iowans' awareness of the cancellation. 

EPA says there are alternative treatments

This process began several years ago. A risk and benefits committee reported to the EPA that carbofuran was an unduly hazardous chemical and there were alternative treatments that could be used. In 2006 FMC Corporation, the makers of Furadan, requested an opportunity to appear before the committee. Iowa State University professor of entomology, Jon Tollefson, was an academic expert who gave his view of Furadan use in field crops and a professor from Purdue also testified concerning Furadan use in horticulture crops. There were letters from state secretaries of agriculture supporting the use of Furadan in crops, data from field experiments and several farmers testified.

Upon considering the information presented, EPA maintained its intention to not renew the registration of carbofuran. FMC appealed the decision, but the appeal was not upheld. The process has now come to the point where the final cancellation of tolerances is occurring. It is likely that FMC will challenge the EPA's conclusions by requesting an administrative hearing, but these rebuttals have not altered the agency's direction so far.

How does this affect the Iowa growers?  

According to ISU's Jon Tollefson, there are several points for farmers and others  to consider:

• This year you will be able to purchase and use Furadan on field crops according to the label.

• Don't purchase and stockpile labeled Furadan. Any crops receiving a Furadan application after January 1, 2010 cannot be legally sold.

• Historically, there has not been very much liquid Furadan used in Iowa. However, this has changed somewhat with the development of genetically engineered corn that is resistant to corn rootworms; the requirement of a refuge planting to preserve effectiveness of the Bt varieties; the development of neonicotinoid seed treatments; and planters that have central-fill seed hoppers. 

These changes have resulted in Bt and refuge fields being planted with no soil insecticide applied for corn rootworm control and a liquid application being made to the refuge after the corn has emerged. Furadan has been a product that fits these needs. Now an alternative product will be needed, he notes.

If alternative treatments for protecting corn from corn rootworm larval feeding are needed, what might be available? If the area planted is to be a corn rootworm refuge, Tollefson says there would be two options. One option would be to add granular applicator units to the planter and the second option would be to buy seed corn that has been treated with the rootworm rate of a neonicotinoid insecticide (e.g., Poncho, Cruiser).

If a postemergence liquid treatment is desired, the options would include chemicals such as Lorsban 4E and Capture 2EC. In general, the planting-time granular insecticides provide the best, most consistent control. There is not as much research information on postemergence liquid applications, he says.

FMC also continues to believe that the EPA used flawed science in its over conservative modeling and will request an appeal of the decision through an Administrative Law Judge hearing. Attached is an FMC response to the EPA announcement.