I am glad you asked that, and I don't really know all the answers{wish I did}. Before I go much further, what is to keep minors from buying gasoline and snorting that? Kids can buy a can of gas, spray paint, hair spray, certain cleaning agents etc.... but liquid nails is the cause of all doppers....,,. I find that hard to believe.
What if I had been out at my truck loading lumber but forgot the liquid nail, so I send my child in to grab it for me, he/she can't, so now I'd have to waste time{which for most is money} to go show ID for something stupid.
I understand we have issues with substance abuse but ID'ing a middle aged man won't do squat to stop the issue/problem. I quess maybe these abuse issue need to be 1st looked at in the home, oops I'm probably bad for writting that, how dare we place responsibilty for children on their parents. There is a small town south of me that has a huge abuse problem{lived there years ago, one reason I took my family and left}. No one can seem to figure out why, in reality all they need to do is look at the parents, {yes they're abusers also, or just plain don't care}. I allways found it funny{weird}, it's harder to get a drivers lic then it is to pop baby's out.
MossRoad, I quess my answer to your question would be start at the home. Then maybe have a better educational program to show kids what is wrong with substance abuse in the schools. I do strongly feel that ID'ing innocent older folks{for stupid stuff} isn't going to do anything.