> I think in general adults should be able to make up their minds about ingesting chemicals that might hurt them. However, it makes sense to make an exception -- if the chemical has addictive properties and empirically is likely to have network effects (i.e. in practice it tends to spread through the community), it seems reasonable for the government to step in and regulate the substance in more substantial ways than enforcing disclosure.

Does it? What result are you trying to produce by this legislation?

If you're trying to produce the result that fewer people use X harmful substance, then it absolutely does not make sense to regulate the substance itself. Evidence suggests that regulation merely makes selling the substance more profitable and buying the substance more "edgy", making the substance more dangerous. Instead, it makes sense to provide better programs for treatment and education around the substance, which results in lower usage, higher recovery rates when someone does use it, and less incentives for people to traffic the substance.

But if you're trying to produce profits for prison corporations and further militarize law enforcement, by all means, let's make all substances illegal.