The Star Brite 89990 MDG Mildew Odor Control Boat Bomb removes and prevents mold/mildew odors within 6 hours. Also removes & prevents any other foul, unpleasant odors. Uses patented system to generate a deep-penetrating chlorine dioxide vapor that thoroughly permeates 100% of treated area. Not to be used while people or pets are present, but treated area is safe for use after being aired out.