Unsymmetrical dimethylhydrazine (
UDMH;
1,1-dimethylhydrazine) is a
chemical compound with the formula H
2NN(CH
3)
2. It is a colourless liquid, with a sharp, fishy, ammoniacal smell typical for organic
amines. Samples turn yellowish on exposure to air and absorb
oxygen and
carbon dioxide. It mixes completely with water,
ethanol, and
kerosene. In concentration between 2.5
nd 95% in air, its vapors are flammable. It is not sensitive to shock.
1,2-Dimethylhydrazine (CH
3NHNH(CH
3)) is also known but is not as useful.