Thursday, February 21, 2008

What is Hydrazine?

Spy Satellite holding toxic hydrazine destroyed.
What is Hydrazine?
Dr. Nitish Priyadarshi

U.S officials say a missile launched from a Navy ship in the Pacific successfully hit a U.S. spy satellite more than 200 kilometers above the Earth today on 21Feb. 2008. The dying satellite stopped communicating with controllers on Earth shortly after it was launched 14 months ago, and it began to slowly fall. The shoot-down was intended to destroy a tank aboard the craft holding 450 kilograms of a toxic fuel called hydrazine. Officials said the fuel posed a danger to humans if the tank survived re-entry.
Hydrazine is the chemical compound with the formula (NH2)2. It has an ammonia-like odor, and is derived from ammonia, but its physical properties are more similar to those of water. Hydrazine is usually handled as 60% aqueous solution. It is mainly used in as a blowing agent in preparing polymer foams, but significant applications also include its uses as a precursor to polymerization catalysts and pharmaceuticals. It is used in rocket fuels
Hydrazine is used in many processes including: production of spandex fibers, as a polymerization catalyst; in fuel cells, solder fluxes; and photographic developers, as a chain extender in urethane polymerizations, and heat stabilizers.
Hydrazine a toxic, flammable caustic liquid and a strong reducing agent. Its odour is similar that of ammonia, though less strong. It is slightly soluble in ammonia and methyl-amine. It is soluble in water, methanol, ethanol, UDMH, and ethylenediamine. Hydrazine is manufactured by the Raschig process, which involves the oxidation of ammonia to chloramine, either indirectly with aqueous sodium hypochlorite or directly with chlorine, and subsequent reaction of chloramine with excess ammonia. Raw materials include caustic, ammonia, and chlorine; these are high-tonnage, heavy chemicals.


Hydrazine is highly toxic and dangerously unstable, especially in the anhydrous form. According to the U.S. Environmental Protection Agency:
Symptoms of acute (short-term) exposure to high levels of hydrazine may include irritation of the eyes, nose, and throat, dizziness, headache, nausea, pulmonary edema, seizures, coma in humans. Acute exposure can also damage the liver, kidneys, and central nervous system. The liquid is corrosive and may produce dermatitis from skin contact in humans and animals. Effects to the lungs, liver, spleen, and thyroid have been reported in animals chronically exposed to hydrazine via inhalation. Increased incidences of lung, nasal cavity, and liver tumors have been observed in rodents exposed to hydrazine

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