Always read labels at home. It has been reported by many that after getting home and didn't catch when they first check them at supermarket.
Peanut schools haven't been around for that long. Less than ten years ago the concept of allergy free zones or peanut free schools was just a concept that was been tested by a handful of schools. Epipen in every classrooms was simply out of the question and trying to educate school nurses and teachers about anaphylaxis allergic reactions was quite a challenge to say the least. Moms had to figure out ways to teach their children how to take care of themselves and find ways to help them self carry and hide the epinephrine auto injectors under their clothing. The good that came out of this lack of knowledge is that most of these children continue to carry their Epipen throughout there lives. Therefore, even if a school is peanut free or has an Epipen in every classroom children with anaphylaxis allergies will benefit tremendously if they get used to carry their own medications during the early school years.
Teaching a toddler what they can or can't eat. At the age of two, I started taking my child to the supermarket almost daily to help him visually learn what he could and could not eat. Learning to read as earlier as possible was a necessity, so the summer prior to entering kindergarten we hire a tutor to teach him how to read. By age four, he was reading labels and could tell if it was safe to eat the food. Explain to kids that f if there is no label or they can't read it is OK not to eat. "Better hungry than risk your life" Parents have to understand that no matter how terrible it feels to tell a child too stay hungry, is better to do so than to expose them to the risk of ingesting foods that can trigger a severe anaphylaxis reaction.