The Department of Sanitation does not collect pressurized oxygen or acetylene tanks because they can explode when compressed by garbage trucks.
You should exchange old pressurized oxygen and acetylene tanks when purchasing a new cylinder.
If the retailer refuses to accept the old cylinder, or you aren't buying a new one, contact another dealer about correct disposal. Welding equipment and scrap metal dealers may accept old cylinders.
View the New York City Fire Code.