The federal government must begin the regulatory process anew before permitting the use of the controversial pesticide Ferriamcide to control fire-ants in the South, U.S. District Court Judge Gerhard A. Gesell ruled yesterday.

The Enivornmental Defense Fund filed suit to block the use of the pesticide on grounds it poses a hazard to humans. Ferriamicide contains the pesticide Mirex, which has been banned because it can cause birth defects and is a suspected human cancer agent.

Gesell's decision means that the Environmental Protection Agency must hold new public hearings and review all evidence, which could take weeks, before granting permission for its widespread use.

EPA had no immediate comment on whether it would resume its efforts to permit the pesticide.

Environmentalists argued that EPA acted arbitrarily in declaring an emergency fire-ant problem in the South. The fund also accused EPA of acting with political impropriety in attempting to permit use of the pesticide.

But Gesell ruled that the fund did not produce sufficient evidence to prove the assertions.

However, he said EPA's decision-making procedures were flawed because the agency failed to make available for public scrutiny documents relating to potentially adverse effects of pesticide - a flaw that could be corrected by beginning the regulatory proceeding anew.

Ferriamicide is manufactured by the state of Mississippi, and its use is sought throughout the South to eliminate infestations of fire ants.