As any parent can testify, there is probably no surer staple of childhood than peanut butter: a pure product of America, consumed at an annual rate of three pounds per person, invented by George Washington Carver, the brown-bag-and-grape-jelly backup for millions of schoolchildren who gag at peas and pre-emptively detest anything cooked in a school cafeteria.

Now peanut butter is under attack at the schoolhouse door. Cheap, nutritious, popular and traditional, it has nonetheless taken its place on the list of substances - like asbestos and lead - that send shivers down the spines of school administrators.Prodded by parents warning of lethal allergies, by the contentions of some researchers that peanut allergies are on the rise and, not least, by a fear of litigation, growing numbers of public and private schools across the United States have banned peanut butter from their cafeterias. Others have declared peanut-free zones or set up committees to figure out what to do.

School officials find themselves balancing the rare risk of death against the danger of being swept up in a faddish hysteria and of trying to anticipate potential legal repercussions of the 1990 Americans with Disabilities Act.

Even those who wonder if the bans have gone too far fear that if they do not act aggressively, they may face liability lawsuits and accusations of discrimination against children disabled by a peanut allergy.

Children are well aware of the debate.

"Well, you can't take chances," said Alex Goldschmidt, a fifth-grader eating pizza in the lunchroom at Trevor Day School, a private school in New York. "I mean, if you kept it here, then they might eat like some kind of food with nuts in it, then something bad would happen, then the next thing you know there would be somebody in the cafeteria that's dead, that's all."

The campaign to ban peanut butter is happening in scattered places where an assertive parent or two - supported by the Food Allergy Network, an 8-year-old advocacy group in Fairfax, Va. - has raised the alarm in schools, contending that peanut allergies are a disability that schools must accommodate under the disabilities law.

The Centers for Disease Control report only 88 deaths among all Americans from allergies to food, including peanuts, between 1979 and the end of 1995. But allergists supported by the Food Allergy Network contend that fatalities are underreported and that 0.5 percent to 1 percent of all Americans suffer from peanut allergies. It estimates that every year 125 people die from food allergies, the majority from peanuts.

While network officials say they are not forcing schools to take any particular action, the schools say that anything less than a total ban seems inadequate to satisfy the critics.

This is the first full year of the peanut ban at Trevor, where children who once ate peanut butter sandwiches now can choose from a sandwich bar including cheese, cold cuts or just plain jelly.

Like many other schools, Trevor, which has two peanut-allergic children among its 240 students, has stored Epipens, injectable epinephrine, an antidote to the asthmalike reaction that can be caused by peanut butter, in strategic spots throughout the building and has trained teachers and cafeteria workers in how to use it.

In rare cases, a peanut allergy can cause a sudden drop in blood pressure and the closing of the breathing passages. An injection of epinephrine or adrenaline can prevent death if administered quickly enough, Burks said.

In its milder form, a peanut allergy can cause itching, swelling, hives, wheezing, coughing, vomiting and diarrhea, doctors say.