WASHINGTON, D.C. — A U.S. federal appeals court decided last week in favor of agricultural chemical companies, when it contended the federal government’s new guidelines regarding insecticides and their effects on salmon were not justified by the science.

Dow AgroSciences v. National Marine Fisheries involved Dow and other companies suing the National Marine Fisheries Service (NMFS) and some activist groups and a fishermen’s association on the West Coast. It was heard in the U.S. Court of Appeals for the Fourth Circuit.

The question at hand had to do with whether the lower court ruled properly in dismissing the chemical makers’ lawsuit when it upheld the scientific validity of the NMFS’ finding that companies’ insecticides were endangering Pacific salmon. The appeals court reversed the lower court’s decision, vacated the agency’s biological opinion (BiOp) and sent it back to the lower court for further action based on the higher court’s ruling.

U.S. House Agriculture Committee Chair Frank Lucas (R-Okla.) praised the court’s decision. “Whether we are talking about (NMFS’) evaluation of pesticides in the Pacific Northwest, the Fish and Wildlife Service’s evaluation of the lesser prairie chicken in the southern Great Plains or countless other decisions, it amazes me how little regard there is within the Services for science and the economic consequences of their actions,” Lucas stated.

“It is my hope that the order of the Fourth Circuit will finally encourage the Services to balance the goals of species protection with the requirement that their decisions be technically and economically feasible.”

Under 1988 federal law, any pesticide that was originally registered for use prior to Nov. 1, 1984, has to be reviewed again in order to make sure the product is safe, using the most up-to-date science.

The three pesticides in question – chlorpyrifos, diazinon and malathion – all were originally registered with the government for use prior to that time, so they had to be reregistered and reevaluated to determine their safety.

Lawsuits involving the pesticides go back to 2001, but eventually it was decided the NMFS had to write a BiOp in order to determine the effects the chemicals might have on salmon.

This report would have the force of law and was completed in 2008. It was used by the U.S. Environmental Protection Agency to determine how the pesticides could be used.

According to the actual BiOp, the NMFS concluded “reasonable and prudent alternatives” for use of these chemicals would avoid the likelihood of jeopardizing the “continued existence” of listed salmon or “resulting in the destruction or adverse modification of critical habitat.” The opinion recommended these chemicals not be applied aerially within 300 feet of salmon-bearing waters.

It also recommended the pesticides be watered-in or soil-incorporated immediately when applied to the ground within 300 feet of salmon-bearing waters, and that a 10-foot vegetated strip or a 20-foot no spray zone be maintained between salmon-bearing waters and use sites where the pesticides are used, as well as a reporting requirement.

But the ag-chemical makers said the BiOp was bad science and the report hadn’t shown how its new guidelines would be “technologically and economically feasible” – one of the requirements under the law.

Although the district court agreed the report wasn’t well written, it accepted the report’s conclusions based on information added later. A toxicologist from the NMFS provided an explanation of the report during a hearing. After this, the court accepted the government’s arguments and dismissed the case.

The companies appealed, however, and the appeals court ruled in their favor. The first problem, it said in a unanimous three-judge panel ruling published last week, was the lower court erred in allowing information that it called “post hoc rationalization.”

This isn’t proper, they said, except under unusual circumstances. In deciding the merits of the BiOp, therefore, the opinion stated the lower court could use only the BiOp itself, not anything which was added later on.

The appeals opinion discusses a few main issues with the BiOp: the 96-hour standard the NMFS used to determine exposure time to the chemicals, water monitoring data the service used and the prescribed use of uniform buffers. The BiOp relied on a “selection of data, tests and standards that did not always appear to be logical, obvious or even rational.

“While the Service may have had good and satisfactory explanations for its choices, the BiOp did not explain them with sufficient clarity to enable us to review their reasonableness. For that reason, we conclude the BiOp is arbitrary and capricious,” the judges added.