Biofoam

Self-sealing Biofoam was a marvel of UNSC medical accomplishment in the 2500's. Biofoam is a space-filling coagulant, antibacterial, tissue-regenerative foam polymer that is inserted into the skin and even deeper into the body itself. This foam keeps damaged organs in place and helps stop bleeding and hemorrhaging. It is, unfortunately, very painful to use, being described as burning ants crawling around the wound or thousands of tiny knives stabbing the recipient. It is an improvised medical option when there are no medics available. Normally bottles of biofoam are found in a Health Pack. Often UNSC medics will use it as a sealing agent during treatment in field hospital. The only downside is that the foam has a preset time limit before it breaks down and the unfortunate person bleeds to death. The time limit is usually about an hour or so depending on the recipient.

By October of 2552, the UNSC MJOLNIR Mark VI armor contained automatic biofoam injectors, which negated the need for Spartans to use Health Packs.