As the parent of a school-aged child, I'm confronted with certain concerns whenever 'room snacks' are involved. My school isn't nearly as draconian as this one, but I'm very aware of the fact that there are kids out there with allergies and the like. So, when my daughter's birthday rolled around and she asked me to bake cookies, I made the decision to make a simple sugar cookie with nonpariels instead of, say, peanut butter cookies or chocolate chip cookies.
Kids are told very specifically not to trade food from packed lunches, since it's assumed that they don't necessarily know that little Jimmy has a life-threatening peanut allergy, or Cindy breaks out in a rash from strawberries. Parents are simply told to be 'careful'.