We used to be able to go to Drag and Racing shops and buy nitrous in tanks. You could even go to welding supply houses and get the tanks refilled / no prescription needed if you said it was for 'drag racing'. Nerds in Ford Pintos buying Nitrous for their dragsters... RIGHT!

Then they got wise and starting adding a horrible mustard-smelling stuff to the nitrous they sold to 'drag racers'. if you want the 'unflavored' stuff you have to have a license. it's a medical thing...

Steve "Past the Statute of Limitations" in Albuquerque