There are too many conflicting ideas, and at this point that's what they are, ideas, to know for sure what the issue is at this stage. I started vaping marijuana about two months ago. I smoked like a fiend in high school, back in the early 80s, and not really since. But my college football days led to a faster breakdown of my body. I have had severe osteoarthritis for the last 18 years. I'm in a near constant state of pain. I've been eating Vicodin like candy, for the last 15 years.
So, it when was passed for medical purposes here in Ohio, where I spend most of my time, I got my card. I primarily use at night, as it keeps the pain from waking me up. And,while certainly not a cure for arthritis, it does significantly help, even when I'm not using. I have entire days now where I'm nearly pain free. But, I haven't had a Vicodin in two months now.
Here,burning the herb is illegal. But, the state tests every component. They test for Thc content of course, but also viruses, bacteria, pesticides, lead,mold, any adulterant, or synergist. It must be pure oil, nothing else. The reason for this is simple really, the end users are people with severe illnesses, rare diseases, or compromised immune systems.
They also test for butane, and carbon dioxide, which are part of the extraction process. If any is present, it has to be destroyed.
This of course, testing from seed to sale, drives up the cost. But it needs to be regulated. Banning isn't the answer, regulation is; just like any brewery, or distillery, they must adhere to strict guidlines.
Same with vaping devices, or marijuana, in my opinion.