NULLODOR is a natural product. Each crystal has an absorption rate of 150%. Liquids are absorbed in a fraction of a second, then the water evaporates slowly to leave dry litter that can be re-used for a long time. NULLODOR completely locks away odours for a month. They are absorbed at the same time as the liquids. Whilst the liquids evaporate, the odours are trapped in the centre of the silica granules, totally blocking ammonia emissions.