Type A porous aluminum oxide is a historically popular desiccant for SCUBA air because it is non-toxic, long lasting, compositionally stable, simple to handle, and has high absorption capacity. Primarily used to remove moisture, it also has limited ability to absorb other gases and liquids. Global activated alumina is formulated as 1/8" diameter spheres. Type A has absorbing power which approaches that of molecular sieve. Packaged in a 1 gal, 6.75 lb bottle.

Molecular sieves, a group of space age chemicals known as zeolites, have outstanding filtration abilities. Their chemical structure is a narrow, rigid, and uniform crystalline lattice which has such precise pore size that it restricts movement of substances on the basis of molecular size! Small molecules, like water, can enter the lattice, but are trapped therein, thus the name "molecular sieve". Molecular sieves are highly effective filtrants for moisture, nitrogen oxide, oil vapor, and...

A specialized form of charcoal, this final filtering agent removes tastes and odors from the air. It absorbs oil and water vapor, chlorine, nitrous oxide, and small amounts of carbon monoxide and dioxide. NOTE: Activated carbon should be the final chemical in the filtration train and must always be preceded by the desiccants. When damp, the effectiveness of charcoal is reduced and may even release previously absorbed contaminants. Also, wet activated carbon of even high quality may form small...