2006 New York Code - Permit.

 
    §  27-4099  Permit.  a.  Gases.  It  shall  be  unlawful  to compress,
  generate, store, or sell any acetylene, Blaugas, Pintsch  gas  or  other
  gases  and  mixtures  of  gases  or  transport  through  a pipe from one
  locality to another any gas, unless otherwise herein provided for, at  a
  pressure  exceeding  six  pounds  to  the  square  inch,  or to compress
  atmospheric air to a pressure exceeding one hundred pounds to the square
  inch or in a compressor with a pressure gauge capable of  exceeding  one
  hundred  pounds  to  the square inch, or in quantities exceeding a total
  container capacity of thirty cubic feet, without a permit.
    b. Toy balloons. It shall be unlawful for any person to fill or charge
  toy balloons with hydrogen or any  other  flammable  gas,  or  to  sell,
  transport, store, or have any such toy balloon in his or her possession.
    c.  Fire  extinguishing  media. No permit shall be required to use, or
  store for use, any compressed gas which is used, or stored to  be  used,
  as a fire extinguisher media.