what is blue ice?
Blue ice (aviation) Blue ice, in the context of aviation, is frozen sewage material that has leaked mid-flight from commercial aircraft lavatory waste systems. It is a mixture of human biowaste and liquid disinfectant that freezes at high altitude. The name comes from the blue color of the disinfectant. Airlines are not allowed to dump their waste tanks in mid-flight, and pilots have no mechanism by which to do so; however, leaks sometimes do occur.