The following standards shall be observed in the conducting of industrial operations permitted in "M-1" and "M-2" Districts.
(a) Smoke. In an "M-1" District no smoke shall be emitted with a density greater than No. 1 according to the Ringlemann's Scale, except that smoke of a density not in excess of No. 2 Ringlemann's Scale shall be permitted for a period not in excess of six minutes in any hour. In an "M-2" District no smoke shall exceed a density greater than No. 2 on the Ringlemann's Scale, except that smoke at a greater density shall be permitted for a period not in excess of six minutes in any one hour.
(b) Fly Ash. No particles from any flue or smokestack in an "M-1" District shall be permitted to escape beyond the confines of the building in which it is produced. In "M-2" Districts no particles from any flue or smokestack shall exceed 0.3 grains per cubic foot of flue gas at a stack temperature of 500 degrees Fahrenheit.
(c) Dust. No dust of any kind produced by the industrial operations shall be permitted to escape beyond the confines of a building in which it is produced in an "M-1" District and beyond the limits of the property being used in an "M-2" District.
(d) Odor. No noxious odor of any kind shall be permitted to extend beyond the lot line.
(e) Gases and Fumes. No gases or fumes toxic to persons or injurious to property shall be permitted to escape beyond the building in which they occur.
(f) Glare. No glare shall be seen from any street or any residential area.
(g) Vibration. No intense earth shaking vibration shall be created or maintained by any industry beyond the property on which it is located.
(h) Noise and Sound. A maximum of seventy decibels at the property line is permitted. Noise is required to be muffled so as not to become objectionable due to intermittance, beat frequency or shrillness. Sound may equal but may not exceed street traffic noise in the vicinity during a normal day work shift period.