I think there is a better way to do this and that is by reducing food. Even if food is allowed, why not limit it to just a few things instead of a gazillion food items that then need to be screened. Something will always slip through the cracks if you offer an unlimited supply of food. Everyone -- kids, teachers, other parents -- want these parties to be fun and not potential ER emergencies.
I wrote an article for Chicago Parent magazine awhile ago, but it is a perennial one in terms of addressing food at school parties.
Plus, here is a recent blog post about going food-free for school parties. This has been one of my most popular recent posts, so I am sharing again for those who haven't seen it.
Don't stress, just be prepared to offer alternatives. And it's never to early to start coaching your child NOT to eat anything until you give it the thumbs up at home.
Please feel free to share my articles and posts with your school and thank you for all you do to keep Halloween parties safe, fun and inclusive!