Odors. There shall be emission of odorous gases or other odorous matter in such quantity as to be readily detectable without instruments. Table III, Odor Thresholds, in Chapter 5 of the Air Pollution Abatement Manual, copyright 1951, by the Manufacturing Chemists Association, Inc., Washington, D.C., or the latest approved revision thereof, shall be utilized as a guide in determining such quantities of offensive odors.