Nitrous oxide
One newer monopropellant under development is nitrous oxide, both neat and in the form of nitrous oxide fuel blends. Nitrous oxide offers the advantages of being self-pressurizing and of being relatively non-toxic, with a specific impulse intermediate between hydrogen peroxide and hydrazine. Nitrous oxide generates oxygen upon decomposition, and it is possible to blend it with fuels to form a monopropellant mixture with a specific impulse up to 325 s, comparable to hypergolic bipropellants.