Sticky foam is an incapacitant, used when less lethal force is required, consisting of various extremely tacky and/or tenacious materials carried in compressed form with a propellant and used to block, entangle, and impair individuals. A National Institute of Justice-funded project at Sandia National Laboratory developed a "gun" which could fire multiple shots of sticky foam. After testing the product for corrections applications, Sandia provided the U.S. Marine Corps' Operation United Shield with sticky foam guns and supporting equipment to assist in the withdrawal of U.N. peacekeepers from Somalia. Problems with this technology include: the serious risk of smothering (suffocating) the subject; skin clean-up (the foam may not be toxic, but solvents are often harsh); "gun" clogging; target