Du Pont Co. knew more than a year ago that its Benlate DF fungicide could damage crops even if farmers used it properly, an internal company document indicates.
A confidential Sept. 10, 1991 memo written by a Du Pont chemist shows that the company may have known far more about the causes of a farming disaster than it has ever disclosed. The memo provides a possible explanation about what may have motivated Du Pont to pay nearly $500-million in crop damages even though the company has never admitted fault.
So far nearly 1,900 farmers, 1,210 of those in Florida, have filed crop damage claims against Du Pont in what has become the costliest man-made agriculture disaster in U.S. history. Du Pont recalled Benlate DF in March 1991.
The memo, written by Du Pont scientist Michael J. Duffy, contains facts never released to the public or to Florida agriculture officials. It contradicts a year of statements by the company, which has always denied it even had a workable theory about how Benlate DF may have caused crop damage.
In part, the document reads "the potential for crop injury exists from use of Benlate DF when used according to the label."
The memo said this damage was possible "since we now know that some allowed treatments are very near the injury threshold inherent in benomyl applied in this formulation." Benomyl is the main active ingredient in Benlate DF.
"It sounds like they're making statements in that memo based on foundational knowledge about Benlate, not just hunches. They've never told the state any of this," said Tim Schubert, chief plant pathologist at the Florida Department of Agriculture.
Du Pont spokeswoman Pat Getter, citing pending lawsuits by farmers, declined comment on the memo, except to say that subsequent research had disproven some "theories" expressed in the document.
Duffy, in a telephone interview, said the memo discussed early findings in greenhouses and in laboratory tests _ findings that he said did not hold up in field tests under actual growing conditions.
"All that I can say is that we have made a heroic effort from a scientific standpoint to find an explanation about what is happening in Florida," the scientist said. "I can tell you we have not developed any data implicating Benlate."
But his two-page memo, written to other Du Pont scientists, suggests otherwise. It said:
Older batches of Benlate stored under hot, moist conditions could decompose and create compounds capable of harming plants.
At one point, a manufacturing mistake led to a higher than normal rate of benomyl being introduced into some batches of the product.
Disease, heat and overapplication of Benlate probably played a contributing role.
Duffy further urged that Du Pont adopt "a firm stance" with farmers who charge that Benlate has caused lasting soil contamination. In the memo Duffy argued that contamination is not possible beyond one growing season.
"I would NOT agree to testing of soil samples or anything aimed at trying to "exonerate' the product," he wrote.
"Rather I would simply tell the grower that we do not believe that Benlate can be the cause and leave it to them to prove us responsible. I think we need to have an innocent-until-proven-guilty mindset, not the opposite."
State officials say Du Pont appears to have adopted a hard-line stance similar to the one outlined in Duffy's memo and it has shared few details of its research.
"I don't want to accuse them of anything. But it sure would have been helpful for our research efforts to have known a year ago what they were doing," said Schubert at the Agriculture Department.
Du Pont officials have said the company is paying damage claims because a "circumstantial" case suggests Benlate may be at fault, but they have always denied proof was available.
"No one, not Du Pont, not any university researcher, and not any independent consultant has been able to reproduce the biological effects," said Du Pont spokesman Morris Bailey at a gathering of reporters in Orlando on May 7, eight months after Duffy's memo was written.