a humidity responsive control device consists of a package having at least one face that is a permeable to liquid and gases and water vapor and is formed by mixing together a ) 5 to 50 % by weight of a hygroscopic polyacrylate and / or pva polymer , b ) 10 to 60 % of porous silica minerals such as vermiculite and perlite , c ) 5 to 50 % of an absorbent such as zeolite or activated carbon for small molecules such as ammonia and d ) 5 to 60 % by weight of an aqueous emulsion of a mixture of an active ingredient of one or more of a bacteriocidal , fungicidal or odor masking compounds . the device is effective at eliminating and masking odors under varying humidity conditions .