Abstract: The present invention provides a passive deodorization device suitable for use in a portable toilet enclosure having a vent tube for venting odors from a holding tank. The deodorization device has a housing having an engagement surface for engaging a vent tube outer surface, and an aperture. Two fingers extend from the aperture into the vent tube. A retention member mounted on the fingers engage a vent tube inner surface and clamp the vent tube wall between the housing and retention member. A deodorizing element slipped into the aperture between the fingers deodorizes the malodorous vapors associated with the toilet.