Cargo Valve The UN31A Cargo Valve Liquitote® IBC was designed to comply with the DOT’s Special Provision 12412. DOT - SP12412, commonly referred to as the pump-off special permit, allows for the discharge of combustible and flammable liquids from an IBC while it is located on a transport vehicle. Under this special permit, only IBCs with bottom discharge systems that include emergency shut-off valves are permitted to discharge hazardous material from a trailer or flat bed.