Bruce Schneier praises A Rational Response to Peanut Allergies and Children.
Many schools attempt to enforce a peanut ban. My son isn't allowed to take peanut butter sandwiches for lunch. In software terms, this is equivalent to perimeter security.
A better way of protecting children with allergies of all kinds is to ensure that the children and their carers are careful, and that they can deal promptly with any accidental ingestion. This is more robust, because it is not dependent upon total reliability of the perimeter defence. It is also more flexible, because it deals with a broader range of allergies (not just peanuts) without insisting on exclusion of every possible allergen.
In software terms, this is equivalent to deperimeterization.