A clampdown on South Australia's vaping industry has drawn fire from advocates who consider it a "perverse" reaction to ideological attitudes that will cost jobs and leave addicts little choice but to revert to smoking.

The state is the frontline of a debate that will continue for some time, as policy makers weigh any benefits for vapers who switch from smoking and the potential to reduce smoking rates, against inadequate knowledge about the risks of e-cigarettes themselves.