Sometimes a fellow can't tell his friends without a scorecard.

President Reagan's war on paper work and his idea to give the states more power is catching flak from the unlikeliest of his friends, the pesticide industry.

The industry has ganged up on a House Agriculture subcommittee and seems on the verge of getting its way in a rewrite of the Federal Insecticide, Fungicide and Rodenticide Act (FIFRA).

That is the 1972 law that sets health and safety protections and governs the production, handling and application of thousands of pesticides, many of them highly toxic, that are used in homes, in gardens and on farms.

After months of hearings and negotiations, the House subcommittee is nearing approval of a FIFRA rewrite that would make these major industry-sought changes:

States no longer could independently require a company to provide more data than the federal government in registering a pesticide. California, which has the most stringent pesticide laws, is pressing with little success to retain its current powers.

Public disclosure of health-and-safety data submitted to the Environmental Protection Agency would be limited strictly, on the ground that disclosure violates trade secrecy. Farm-labor and environmental groups, along with the March of Dimes birth-defects foundation, are vigorously opposed to that provision.

Companies would be given 15 years instead of FIFRA's current 10 for "exclusive use" of pesticide registration data and they would get more liberal treatment in registering a new product.

There are other changes, made at the behest of the industry and the American Farm Bureau Federation, that have farm-worker groups in a dither.

The subcommittee's latest draft bill, for example, dropped a farm worker's right to sue in case of injury from a pesticide and omitted other proposed protections on field use of dangerous chemicals. But the new bill gives companies certain rights to sue for wrongful disclosure of their trade secrets.

An irony here is that the administration and EPA are not enthusiastic about the major changes sought by the pesticide makers. They see more cost for Uncle Sam, more lost time and more paper work.

For months, EPA, through John Todhunter, assistant administrator for pesticides and toxic substances, has been telling subcommittee Chairman George E. Brown Jr. (D-Calif.) that the simplest thing would be to extend the law without change.

"Our basic concern is that we are not sure until we have clearly identified a better way to do something that we should go in and change the law," Todhunter said during one of the hearings.

But such groups as the Pesticide Producers Association, the National Agriculture Chemicals Association and the Chemical Specialties Manufacturers Association put their considerable muscle on the subcommittee and movement began.

As Brown's subcommittee began final drafting of a new FIFRA bill yesterday, EPA was going along reluctantly with the tide and the hearing room was jammed with industry lobbyists who watched attentively.

The first two signs of the way things are came on votes on amendments by Reps. Floyd J. Fithian (D-Ind.) and William C. Wampler (R-Va.). Fithian proposed tighter limits on "new uses" of pesticides on certain crops. EPA said it would cost too much and Fithian lost on a tie vote.

Wampler wanted to ban EPA from trading certain technical data on pesticides with other countries. EPA opposed the amendment, but Wampler said industry needed it because of fears that other nations would misuse confidential data.

The clincher came when Brown, in an unusual gesture, invited an industry official for an opinion. Industry's "strong concern," he said, was that communist countries might glean U.S. trade secrets.

The amendment passed, with Brown casting the only "no."