As kids across the country start the school year, many schools are facing a new challenge -- how to protect an increasing number of students with severe food allergies.
Fourth-grader Sam Spear is part of that growing group.
"I'm allergic to peanuts," he said.
On Sam's first day of school, for instance, his teacher explained the rules: "This year, we are not going to be trading food," she told the class.
Many schools are taking quite drastic measures to keep children safe.
Sam's school and many others have peanut-free tables in their cafeterias. Other schools have a long list of banned foods -- everything from homemade snacks to strawberries to sesame seeds.
A New York City nursery school has set aside one classroom for snacks containing no eggs or dairy products. At another school near Charlotte, N.C., cafeteria workers are careful to cook without using peanut products, which means hours spent scrutinizing food labels.
"One life lost is too many," said Cabarrus County Schools Assistant Superintendent Jim Amendum. "We think this is a reasonable accommodation to make."
In some cases, even a student's lunch card is encoded to warn of any allergies.
No one is certain why food allergies are on the increase among children. Theories include the way peanuts are cooked, the diets of young children and America's super-clean society, which can perhaps lead to increased allergy susceptibility.
Whatever the reason, schools are taking it seriously.
At Sam's school district in Franklin, Mass., children with severe allergies are now allowed to carry epinephrine to be injected immediately after an allergic reaction.
"Safe allergy practices in school provide my son and others like him equal access, so they are not afraid to learn," said Sam's mother, Anne Spear.
Some schools, however, are already being forced to back off on banning certain foods after receiving complaints from parents who say they're going too far.
One top allergist agrees, noting that the new measures might even give children a false sense of security.
"It might make them more likely to share food with somebody if they think there is no risk that there is a peanut around," said Dr. Robert Wood, a professor of pediatrics at Johns Hopkins University.
Ultimately, says Wood, the solution lies not in banning a long list of foods, but in educating kids with allergies to avoid any food that may pose a danger. Schools say it doesn't hurt to be extra careful.
ABC News' Lisa Stark filed this report for "World News Tonight."