PURPOSE: Pulsatile lavage devices are routinely used following debridement of contaminated wounds to further debride and cleanse the surface of the wounds. A long-standing concern is the potential for environmental contamination of distant sites and personnel by aerosols and projectile droplets from use of the devices. This study was designed to determine if a new device which encloses the wound site (Wound Irrigation Bag, Pulsecare Medical LLC, North Andover, MA) could contain potential contaminants. METHODS: Six cm by six cm by 1 cm deep wounds were created in large pieces of muscle (n = 6), and were deliberately infected with Staph. hominus. The muscle specimens were allowed to sit overnight at room temperature to allow for colonization. The next day the muscle specimens were transported to the animal OR. Blood agar plates were placed at the intersection of 3 concentric semicircles at 1, 2 and 3 feet distance from the specimen and 5 rays radiating form the specimen at 0o, 45o, 90o,135o and 180o. The same surgeon use 1.5 liters of saline with a battery operated pulsatile lavage device to irrigate each specimen. Three specimens were irrigated without the device, and three specimens had the Wound Irrigation Bag secured around the wound and the barrel of the pulsatile lavage device was inserted through the neck of the bag and the wound then irrigated. The blood agar plates were incubated overnight at 37o C and the number of colony forming units (CFU's) counted on each plate. RESULTS: For the control (non-Bag) specimens, the mean number of CFU's at 1 foot was 350 + 159, at 2 feet 79.4 + 65.7, and at 3 feet 14.5 + 14.0. For the specimens to which the Wound Irrigation Bag had been secured, the number of CFU's at 1 foot was 0.33 + 0.69, at 2 feet 0.20 + 0.4, and at 3 feet 0.33 + 0.79. The surgeon was right handed and there was a tendency for a greater number of CFU's on the blood agar plates on the right side of the control specimens. CONCLUSIONS: Use of the Wound Irrigation Bag was successful in containing contaminated aerosol and projectile droplets during pulsatile lavage irrigation of deliberately infected muscle specimens.