NYC Zoning Handbook:
Manufacturing Districts: M3
M3 districts are for heavy industries which generate noise, traffic and
pollutants. Typical uses include chemical and power plants and
foundries. The districts are usually located near the waterfront and
buffered from residential areas. Even in M3 areas, certain uses with
nuisance effects are required to conform to minimum performance
standards. The two M3 districts differ only in parking requirements.
M3: Heavy manufacturing - low performance
Heavy manufacturing use
M3-1 FAR: 2.0
Parking: required
Central manufacturing areas
M3-2 FAR: 2.0
Parking: not required