(Please note that I realize that my views do not cover every possible scenario, and I also realize that younger children may have different needs.)
I have thought a lot about food bans in schools, since Sophie has food allergies and since our school has considered a food ban. I am personally not in favor of food bans. I have three basic reasons to oppose them. First, a food ban is unnecessary for most people with even severe food allergies. Second, a food ban creates a false sense of security for those who do have an extremely sensitive allergy. Third, other measures would be more effective in preventing classroom contamination than a food ban.
Food bans--completely eliminating a particular food or food group--are unnecessary for most people with food allergies. Very few people over the age of 4 will have a reaction solely based on the presence of their food allergen. There are many anecdotes about reacting when a sibling ate a peanut butter cup or other similar things, but in reality most children will not react unless they come into direct contact with the allergen. In the rare instance that a child does struggle with allergies after eating with other children, special arrangements might be made for that child to eat in a separate area.
In the event that a food is prohibited from a school (or other environment), it can create a false sense of safety because, in actuality, it is nearly impossible to monitor or enforce a ban like this. While children may move away from peanut butter sandwiches, they will continue to bring other items containing peanuts, such as granola bars and cookies. A situation could easily arise where an allergic child makes an assumption of safety about foods that are contaminated. Additionally, banning a single food, like peanuts, will not solve food allergy problems for most schools. Most children have more than one food allergy and peanuts are not necessarily their biggest concern. Should we start banning multiple allergens from schools?
There are several alternatives to food bans that should be considered. Schools can designate specific areas for eating, and allow food only in those areas. One model might be that children eat all of their snacks and meals in the lunchroom. For a school with no lunchroom, all food could be consumed at the child's own desk. In both scenarios, the areas would be cleaned immediately after every meal. Schools can also institute hand washing before and after lunch, to prevent contact with allergens on the playground and in other areas of the school. Another possibility is to institute partial bans; based on the allergens affecting each classroom, ban the offending foods for that classroom only.
These alternatives to the whole school peanut ban are easier to implement and enforce, can be customized for the needs of the particular student, are less restrictive to the students in general, and model solutions that are more adaptable to the outside (of elementary school) world. In the long run, I believe that students with food allergies will be safer and better equipped to manage their food allergies if these types of ideas are utilized in place of the more generalized food bans.