By Jonathan D. Rockoff

After warning Americans for six weeks against eating certain kinds of tomatoes, federal health officials gave the all-clear yesterday - without ever finding solid evidence that tomatoes were the cause of the largest outbreak of food-borne illness in at least a decade.

In lifting the salmonella warning, the Food and Drug Administration met the demands of the tomato industry, which had been requesting the action.

But the move is unlikely to stop tomato growers, packers and sellers from pushing for $100 million or more in federal aid to reimburse them for losses.

Health officials trying to track the cause of the illness are now concentrating on jalapeno peppers and serrano peppers.

Investigators are currently in Mexico to examine a pepper-packing plant.

"Tomatoes on the market currently are safe to consume," Dr. David Acheson, the FDA's associate commissioner for foods, said in a conference call with reporters.

Despite the developments, health officials refused yesterday to absolve tomatoes.

Interviews with early victims pointed to certain tomatoes as likely suspects. Investigators are pursuing the theory that the outbreak started with tainted tomatoes, which then contaminated peppers.

More than 1,200 people have fallen ill from the Salmonella saintpaul strain, including 36 in Maryland. Though the number of people infected has continued to rise, there are signs that the outbreak is slowing down.

"It does appear to have decreased in intensity beginning in mid-June," said Dr. Robert Tauxe, deputy director of the Centers for Disease Control and Prevention's division of food-borne diseases. The rate that people are reporting infections dropped to 19 a day in mid-June from a peak of 33 people a day just weeks earlier.

But the progress wasn't enough to curb criticism of the government's food safety system.

"It is absolutely outrageous that we are 90 days into the salmonella outbreak and the FDA and CDC still cannot determine the source of contamination," Rep. Diana DeGette, a Colorado Democrat who has proposed reforms, said in a statement.

The FDA first warned consumers to avoid eating certain raw tomatoes on June 7, after interviews with early victims pointed to fresh red round, red plum or red Roma tomatoes.

Acheson said investigators have failed to find any evidence of a tainted tomato. He said the agency lifted the warning because none of the farms suspected in the outbreak is now producing tomatoes. The tomato industry has been making that point since last week in arguing for the all-clear action.

"All of the tomato farmers may suffer long-term from the stigma that was attached," said Tom Nassif, president of the Western Growers Association, which has members in Arizona and California.

Nassif thanked the FDA for lifting the warning but said the industry is asking Congress for compensation because it appears their heavy losses resulted from mistaken speculation. "I still think it's very possible that tomatoes were never involved," he said.

Health officials acknowledged that it's possible tomatoes weren't responsible, but they continue to stick by statistical evidence that found a strong link to tomatoes.

That unwillingness to clear tomatoes troubles tomato suppliers, who fear customers won't return without a full declaration of innocence.

"They have permission to sell, but the FDA is not giving a clean bill of health, and that's going to affect consumer confidence," said Jim Prevor, editor of the trade publication Produce Business.

Prevor said the food industry will ask Congress during hearings later this month for clear standards guiding government decisions on when to alert consumers and when to remove those warnings.

The government is still warning that the elderly, the young and people with compromised immune systems should avoid eating jalapeno peppers and serrano peppers. With that warning and the focus on spicy peppers, pepper growers now fear that their $120 million-a-year industry will suffer the same as their tomato counterparts.

The United Fresh Produce Association, the food industry's leading trade group, issued a statement calling on investigators to wrap up their probe of peppers "quickly so that either the problem can be identified or, if not, these products can be cleared as well."