Re: contamination from use: If you look into it, you'll find the "contamination" is that with a sensitive enough test, you can tell it's there.
The six figures in damages tend to be self-inflicted. The NZ government spent hundreds of millions on "meth house" remediation that by any rational analysis didn't need to be done.
https://i.stuff.co.nz/national/politics/104287037/rental-met...
Agree that manufacture is a totally different story.