Inhalant Abuse Question?

I have a question about teenagers and abusing common products as a way of "getting high" and causing brain damage when concentrated high enough. I know the list goes on and on of thousands of varying products but my question relates to expo markers. Sadly, many kids are using these in school and since they are not really illegal since they have a useful purpose, we don't really see the teachers doing a lot of things about it. Is it as dangerous if these teenagers are huffing or inhaling the non toxic type since teachers don't carry around the toxic types? I strongly urge all of you to become aware of the dangers of inhalants and if you have kids talk with them now before it is too late. Common abused products include gasoline, propane, paint thinner, whipped cream cans, cooking spray, nail polish remover, etc. Thank you all so much for taking the time to answer this question.