Deodorants and gas filters therefor

A gas filter, comprising:

• a body containing a monolithic filtering medium comprising a ceramic material containing 5 to 100% by weight of a calcium phosphate compound having a molar ratio of calcium to phosphorus of 0.8 to 2.0, and said ceramic material being carried on a supporting material or incorporated into a supporting material, so that said ceramic material is capable of performing as a deodorant, said ceramic material having a pore size of 100 .mu.m to 5 mm and a porosity of 20 to 80%, wherein the pore size of the filtering medium is gradually reduced in a direction from an inlet side of the gas filter to an outlet side of the gas filter.

A gas filter containing therein a ceramic material containing 5 to 100% by weight of a calcium phosphate compound having a molar ratio of calcium to phosphorus of 0.8 to 2.0, said ceramic material being selected from the group consisting of powders, granules, porous granules and porous blocks, and said ceramic material being carried on a supporting material or incorporated into a supporting material, so that said ceramic material is capable of performing as a deodorant, the ceramic material in an inlet side of the gas filter is sintered at a higher temperature than the ceramic material in an outlet side of the gas filter.