Indianapolis-based Dow Agrosciences LLC and two other pesticide makers won a bid to overturn U.S. National Marine Fisheries Service proposals to protect salmon when an appeals court found the agency’s decision “arbitrary and capricious.”

The fisheries service recommendations to protect salmon from the pesticides chlorpyrifos, diazinon and malathion were based “on a selection of data, tests and standards that did not always appear logical, obvious or even rational,” the appeals panel in Richmond, Va., ruled Thursday, reversing a lower court and sending the proposals back to the fisheries service.

The fisheries office also failed to supply an economic reason to ban pesticides from buffer strips of land abutting salmon habitats, according to the ruling by Judge Paul Niemeyer, writing for a three-judge panel.

“By not addressing the economic feasibility of its proposed ‘reasonable and prudent’ alternative providing for one-size-fits all buffers, the Fisheries Service has made it impossible for us to review whether the recommendation satisfied the regulation and therefore was the product of reasoned decision-making,” Niemeyer wrote.

The fisheries service, a unit of the National Oceanic and Atmospheric Administration, is reviewing the ruling, Fionna Matheson, a NOAA spokeswoman, said in an e-mail.

Stephen Mashuda, an attorney for Earthjustice, a San Francisco-based environmental advocacy group that joined the case on the government side, predicted that the fisheries service will be able to supply the evidence to back up its position the the pesticides pose a threat to salmon and related species, such as steelhead trout.

“We’re still confident that the agency’s ultimate conclusions about the pesticides will stand,” Mashuda said. “These are three of the most toxic pesticides on the planet, to wildlife and to humans.”

Garry Hamlin, a spokesman for Dow Agrosciences, said the company is pleased by the ruling.

Dow was joined in the case by Makhteshim Agan of North America Inc. and Cheminova Inc. U.S.A.