GB685822A - An improved filtering agent for tobacco smoke - Google Patents

Abstract

To convert the carbon monoxide in tobacco smoke to carbon dioxide, it is passed over metal oxides, including manganese dioxide and cupric oxide, kept dry by admixture with, e.g. three times the quantity of, slaked lime. A preferred oxide mixture is:-60 per cent manganese dioxide, 38 per cent cupric oxide, 2 per cent ferric oxide and traces of silver oxide and cobalt oxide. Used in conjunction with tar and nicotine absorbents such as cotton, active charcoal and silica gel in a tubular filter unit as for insertion in a cigarette holder, the oxides are placed at the end of the unit nearest the smoker's mouth.