EDUCATORS: If 1 kid is allergic to something, do you keep it out of the classroom?

So my son is going to (a new school) the 1st grade and I got a sneak peak at last year's list to kind of go ahead and start buying supplies. One of those supplies is play-doh.

Now, in kindergarten at his last school, his class played with play-doh. Play-doh has wheat in it and every time the class played with it, my son would come home in respiratory distress (wheezing). (He has a lot of allergies). So, we got him some kinetic sand which helped, but even being around the other kids when they played with it, he would wheeze.

I will be sending him with kinetic sand, and I want to ask his teacher if I can buy a lot of kinetic sand for the classroom. Of course, I don't expect the teacher to bend over backwards for him. It's just stressful because I didn’t think first graders played with it, and I thought that scary chapter was over. I don't want my son going through that again. I can't homeschool because I work. I guess I'm just frustrated.

So teachers/educators, have you ever kept something out of the classroom because ONE child reacted to it? Would you be willing to let a parent purchase an alternative for the entire class to keep their child safe? Any advice?