On Tuesday, federal authorities cleared fresh tomatoes being harvested in Florida and all those grown in California - the nation's top two tomato-producing states - of responsibility in the national food poisoning scare, which has sickened 167 people since April.

But farmers said the list of safe-to-eat varieties still isn't enough to convince consumers that tomatoes are safe for salads and salsas, or to move their crops back on grocery shelves and restaurant menus.

"The impact on my company could be big, but it could be huge on the industry overall because tomatoes are so popular," said Tom Deardorff, a fourth-generation Ventura County grower who ships vine-ripe and Roma tomatoes to some of the retail distributors that have temporarily banned the fruit. "Every hamburger in a sandwich and every salsa served with Mexican food has tomatoes. We're very concerned."

For consumers there is a large amount of confusion over which tomatoes are safe.

The Food and Drug Administration released guidelines for consumers and businesses on Tuesday:

• Stay Away From: Red plums, Roma or round tomatoes. Do not eat these tomatoes even after cooking them. If you have red plum, Roma or round tomatoes in your home and are unsure of their source, contact the store or place of purchase. Those three varieties are thought to have caused the illnesses.
• Still Safe: Cherry tomatoes, grape tomatoes, tomatoes with the vine still attached and homegrown tomatoes.
• The FDA also warned consumers to be careful when buying tomatoes at a farmers market instead of a grocery store as it is not a guarantee they are safe. Consumers should ask retailers at farmers markets about the source of their tomatoes.

Federal officials are still tracking the source of the bacterial outbreak, which the Centers for Disease Control and Prevention said is linked to a rare strain called salmonella saintpaul.

Still, growers say the outbreak has affected peoples' perceptions of all tomatoes, especially since major restaurant and grocery chains including McDonald's Corp., Wal-Mart Stores Inc. and Burger King Holdings Inc. announced earlier this week they were withdrawing the three varieties from their shelves and menus unless they were grown in state and countries not linked to the scare.

The FDA said it's working "hard and fast" to trace the source of the outbreak.

The U.S. Centers for Disease Control and Prevention said the 167 cases reported since mid-April involve salmonella with the same "genetic fingerprint." States reporting illnesses linked to the outbreak include: Arizona, California, Colorado, Connecticut, Idaho, Illinois, Indiana, Kansas, Michigan, New Mexico, Oklahoma, Oregon, Texas, Utah, Virginia, Washington, and Wisconsin.

The list of supermarkets and restaurants yanking the affected varieties of tomatoes is growing.

They include McDonald's, Wal-Mart, Burger King, Kroger, Outback Steakhouse, Winn-Dixie and Taco Bell.

At least 23 people have been hospitalized.

Salmonella is a bacterial infection that causes fever, diarrhea, and abdominal cramps that typically last four to seven days. Symptoms include headache, stomach pain, diarrhea, nausea and vomiting.