Deodorizers are mainly strong oxidizing and deoxidizing substances, as chlorine and its oxides, sulphurous acid, nitrous acid, ozone, peroxide of hydrogen, permanganate of potassium. Charcoal, in addition to oxidizing, absorbs and condenses the foul-smelling gas. Those which are most commonly used as deodorizers for the air of rooms are chlorine or its oxides set free from chlorinated lime.

For removing smells from the hands, carbolic acid is to be preferred to others, and for deodorizing faecal matters, permanganate of potassium, carbolic acid, or charcoal. A mixture of eight or nine parts calcined dolomite (magnesia and lime) with one or two of peat or wood charcoal is not only an excellent deodorizer, but increases the value of the faecal matters as manure.