Manufacturing, assembling, converting, altering, finishing, cleaning or any other processing of products, provided that not more than 40% of the total floor area shall be so used. At no time shall any premises be used in such a manner as to cause the emanation therefrom of offensive or noxious odors, vapors, fumes, glare, dust, smoke, gas, vibration, noise or radiation or be used in such a manner as to cause injury, offense, annoyance or disturbance to any of the surrounding properties and to their owners and occupants. Sales of any kind to the general public are prohibited.