BBJ FreshDuct Deodorizer Concentrate. FreshDuct contains BBJ EnviroGard™, an encapsulation control agent that controls odors by both encapsulating and breaking down odor molecules, while time releasing a fresh fragrance. BBJ FreshDuct Odor Eliminator leaves the air fresh and clean. Our duct cleaning products are formulated with non-toxic and readily biodegradable ingredients meaning there is no need to evacuate the premises during application. This container can mix up to 5 gallons of RTU deodorizer. Download MSDS