A permit is required for any air compressor that compresses non-flammable gas (including air) at pressures above 100 pounds per square inch (psi). However, outdoor air compressing (other than a fair or festival) is not required a FDNY permit. The air compressor must be performed by or under the supervision of a person holding a Certificate of Fitness (A-35). This Certificate of Fitness is valid only for the specific person to whom it is issued and can be used anywhere within New York City.
