23 CAR § 464-601. Gas purity

(a) All gas supplied to customers shall not contain more than one (1) grain of hydrogen sulphide per one hundred standard cubic feet (100 cu. ft.). (b)(1) All gas supplied to customers shall not contain more than twenty (20) grains of total sulphur per one hundred standard cubic feet (100 ct. ft.). (2) Mercaptan sulphur shall not constitute any portion of the allowable total sulphur content. (c) All gas supplied to customers shall not contain impurities that may cause excessive fumes when burned in a properly designed and adjusted burner.