UDMH

UDMH, or unsymmetrical dimethylhydrazine, is a volatile, colorless to pale liquid with the chemical formula C2H8N2. It is a hydrazine derivative in which the two methyl substituents are located on different nitrogen atoms, giving the structure CH3-NH-NH-CH3. It is miscible with water and many organic solvents, and it is a strong reducing agent with notable toxicity and corrosiveness.

In rocketry, UDMH has been used as a liquid bipropellant component. It is commonly paired with oxidizers such as nitrogen tetroxide (N2O4) or inhibited red fuming nitric acid (IRFNA). The combination is hypergolic, meaning the fuel and oxidizer ignite upon contact, enabling reliable ignition without an external ignition system. UDMH has been employed in various space launch vehicles and missiles, particularly in Soviet and Russian programs, as well as in other fleets during the Cold War era.

Production and handling notes indicate that UDMH is manufactured commercially by methylation of hydrazine under controlled conditions. It is handled and transported under strict safety protocols due to its toxicity, carcinogenic potential, and corrosivity. Exposure can occur through inhalation, ingestion, or skin contact, with significant health and environmental hazards if released. Storage typically requires corrosion-resistant, sealed systems and separation from strong oxidizers to minimize accidental reactions. Environmental concerns and regulatory controls surrounding UDMH reflect its hazardous nature and historical use in aerospace propulsion.