I am sure there are many things that are school safe, but here is a quick list of what I could think of quickly.

First and foremost: guidance/instruction on what to do in an emergency, go over several possible scenarios.

A list of contacts with home/business and cell phone numbers and several dollars in small denomination change to make calls.

A whistle, small LED flashlight, pencil and paper, foil package drink and snack, some string/550 cord

A family and pet photo(s) and if of a particular religious persuasion – a short prayer.

A small First Aid Kit and some basic instruction on how to use the items.

If they wear glasses, an extra pair even if it is their old prescription, as most of time they would be better then nothing.

Pete