You can buy food-grade liquid nitrogen for ice cream from . Because it is a hazardous material that evaporates rapidly, it is not usually sold in standard retail stores; you must visit specialized distributors with a proper cryogenic dewar (vacuum flask) for transport . Where to Buy Liquid Nitrogen
: Always ask for Food Grade (FG) nitrogen. Industrial or "technical" grades may contain impurities or oils from the compression process that are not safe for consumption .
: Distributes Food Grade refrigerated liquid nitrogen through their specialty gas division . Vital Requirements for Ice Cream Making
) and can cause instant, severe frostbite or "burns" upon skin contact .