You obviously have no idea how serious peanut allergies can be. Even 1/1000 of a peanut (could be airborne) can cause an allergic child to go into anaphylactic shock (I've read that 20% of all anaphylactic shock cases in ERs are peanut allergies). I guess that is worth a PB&J.
The question isn't whether it is worth a PB & J. The question is, do you love your child enough to do the right thing for them? We all know are children are special. The child with a peanut allergy, though, should not affect 400 other children because of his allergy. If it's that severe, he should be homeschooled. End of story. I get wanting to keep your child safe. I don't get outright selfish behavior which is what that teaches.
My question is this: At what point do you think it's improper for the minority to affect the rights of the majority? If one kid in ten had a risk of a severe reaction or worse, that's more than prevalent enough to ban a particular food. What if its only one kid in a thousand (about the student body of many schools) or one kid in a million?
Practically every food substance can cause an allergic reaction in somebody, if you look hard enough. Where do we draw the line?
Please don't misunderstand me, freedom to eat a PB&J is not a Constitutional right. We all gave up our rights to be protected by the fire-resistant properties of asbestos, because some people got cancer from it, and I think that it was a worthwhile trade. Clearly, the peanut is not an essential in any human diet, and if there are inherent properties about peanuts (like the volatility of the oils cited in this thread) perhaps they are like the other substances we have banned that only affected a relatively few people.
But where do you draw that line?