N.Y.C. Admin. Code § 24-151: § 24-151 Emission of air contaminant; concealment and masking restricted.

(a) No person shall cause or permit the installation or use of any device or use of any means which, without resulting in a reduction in the total amount of air contaminant emitted, conceals an emission of the air contaminant which would otherwise violate subchapter six of this code.

(b) No person shall cause or permit the installation or use of any device or use of any means designed to mask the emission of an air contaminant which causes or may cause detriment to the health, safety or welfare of any person.