The chemical industry, apparently on its way to winning major changes in federal pesticide laws, ran into a legislative laboratory problem yesterday for which it had no antidote.

An industry-sought revision of the Federal Insecticide, Fungicide and Rodenticide Act (FIFRA) was about to be adopted when it suddenly got bottled up by Rep. George E. Brown Jr. (D-Calif.) and held in subcommittee for "curing."

Brown indicated that he will keep the bill in the House Agriculture subcommittee that he chairs until the industry shows more willingness to compromise on a controversial states'-rights provision.

"It seems we only make progress under the impetus of pressure," Brown said. "A little bit more pressure might be beneficial . . . I am hopeful that further examination by the parties involved might produce a better bill."

The main stumbling block was a new section that would limit the power of individual states to require more data than the federal government before a pesticide could be registered.

States, led by California, which has a strong pesticide-control program, want to retain the power they have in present law. The Reagan administration also wants it retained.

The chemical lobby, however, pushed for a change that would give the Environmental Protection Agency new authority to reject a state's demands for additional registration data. EPA "strongly opposed" the change.

Brown warned that the provision was so controversial that the rewrite of FIFRA, hammered out during months of debate and difficult negotiation, very probably would be killed.

And, he added wryly, "I hate to see Republicans go against their administration."

The five GOP members of the subcommittee got his point but disagreed. They and two other Democrats voted against a Brown amendment to strike the industry-backed limits on states from the bill. The vote was 7 to 2.

Later, however, with drafting apparently completed, Rep. William C. Wampler (R-Va.) moved to order the bill reported out of subcommittee. Chairman Brown, in a gambit that caught all sides off guard, voted three proxies against Wampler. The Virginian lost on a 6-6 tie and Brown said he would sit on the bill.

Before Brown screwed down the lid on his pressure cooker, the subcommittee cleared away several other major obstacles that had created contentious debate between industry and environmentalists, although the industry got most of what it wanted.

One compromise would allow small pesticide formulators greater access to technical data developed by large firms, a move aimed at stimulating competition and preventing a few major companies from controlling the lucrative agricultural pesticide market.

Another would allow companies to limit public access to technical data on new chemicals, but it set a five-year statute of limitations on holding such trade secrets--a compromise only begrudgingly accepted by environmentalists.