| abstract |
A filter composition effective in reacting with airborne or gaseous organic impurities, such as formaldehyde. The filter composition is formed from a filter substrate, such as for example, a fibrous web or extruded carbon block, treated with tris-(hydroxymethyl) aminomethane. The unexpected result of this combination is a longer lasting filter capable of adsorbing organic airborne impurities for a much longer period of time than an untreated filter media of the same type. The removal of formaldehyde is presented as an illustrious example. |