Section 204.52 - Portable air compressor noise emission standard(a) Effective January 1, 1978, portable air compressors with maximum rated capacity of less than or equal to 250 cubic feet per minute (cfm) shall not produce an average sound level in excess of 76 dBA when measured and evaluated according to the methodology provided by this regulation. Effective July 1, 1978, portable air compressors with maximum rated capacity greater than 250 cfm shall not produce an average sound level in excess of 76 dBA when measured and evaluated according to the methodology provided by this regulation.(b)In-Use Standard. [Reserved](c)Low Noise Emission Product. [Reserved]