LCSS: HYDRAZINE

Substance

Hydrazine

(Diamide, diamine)

CAS 302-01-2

Formula

Physical Properties

Colorless oily liquid that fumes in air

bp 113.5 °C, mp 1.4 °C

Miscible with water

Odor

Fishy or ammonia-like odor detectable at 3 to 4 ppm (mean = 3.7 ppm)

Vapor Density

1.04 (air = 1.0)

Vapor Pressure

14.4 mmHg at 25 °C

Flash Point

38 °C

Autoignition Temperature

24 °C on iron rust surface; 270 °C on glass surface

Toxicity Data

LD [50] oral (rat)

60 mg/kg

LD [50] skin (rabbit)

91 mg/kg

LC [50] inhal (rat)

570 ppm (744 mg/m [^3]

; 4 h)

PEL (OSHA)

1 ppm (1.3 mg/m [^3]

)--skin

TLV-TWA (ACGIH)

0.1 ppm (0.13 mg/m [^3]

)--skin--suspected human carcinogen

_(proposed)

0.01 ppm (0.013 mg/m [^3]

)

Major Hazards

Possible human carcinogen (OSHA "select carcinogen"); corrosive to eyes, skin, and mucous membranes; highly flammable and reactive.

Toxicity

Hydrazine is extremely destructive to the tissues of the mucous membranes and upper respiratory tract, eyes, and skin. Skin contact with the liquid can result in severe burns; hydrazine is readily absorbed through the skin, leading to systemic effects, which may include damage to the liver, kidney, nervous system, and red blood cells. Hydrazine vapor is irritating to the nose, throat, and respiratory tract, and inhalation of high concentrations may be fatal as a result of spasm, inflammation, chemical pneumonitis, and pulmonary edema. Symptoms of exposure may include a burning sensation, coughing, wheezing, laryngitis, shortness of breath, headache, nausea, and vomiting. Hydrazine vapor is extremely irritating to the eyes and can cause temporary blindness. Eye contact with the liquid can result in severe burns and permanent damage. Hydrazine is not considered to have adequate warning properties.

Hydrazine is listed by IARC in Group 2B "possible human carcinogen" and is classified as a "select carcinogen" according to the criteria of the OSHA Laboratory Standard. Chronic exposure to subacute levels of hydrazine can cause lethargy, vomiting, tremors, itching and burning of the eyes and skin, conjunctivitis, and contact dermatitis. Hydrazine has been found to exhibit reproductive and developmental toxicity in animal tests.

Flammability and Explosibility

Hydrazine is a flammable liquid (NFPA rating = 3) over a very broad range of vapor concentrations (4.7 to 100%). Hydrazine may undergo autoxidation and ignite spontaneously when brought in contact with porous substances such as rusty surfaces, earth, wood, or cloth. Fires should be extinguished with water spray, carbon dioxide, or dry chemical extinguishers.

Reactivity and Incompatibility

Hydrazine is a highly reactive reducing agent that forms shock-sensitive, explosive mixtures with many compounds. It explodes on contact with barium oxide, calcium oxide, chromate salts, and many other substances. On contact with metal catalysts (platinum black, Raney nickel, etc.), hydrazine decomposes to ammonia, hydrogen, and nitrogen gases, which may ignite or explode.

Storage and Handling

Because of its carcinogenicity, reactivity, and flammability, hydrazine should be handled using the "basic prudent practices" of Chapter 5.C, supplemented by the additional precautions for work with compounds of high chronic toxicity (Chapter 5.D), flammability (Chapter 5.F), and reactivity (Chapter 5.G). In particular, work with hydrazine should be conducted in a fume hood to prevent exposure by inhalation, and splash goggles and impermeable gloves should be worn at all times to prevent eye and skin contact. Hydrazine should be used only in areas free of ignition sources. Hydrazine should be stored under nitrogen in containers placed in secondary containers in areas separate from oxidizers and acids.

Accidents

In the event of skin contact, immediately wash with soap and water and remove contaminated clothing. In case of eye contact, promptly wash with copious amounts of water for 15 min (lifting upper and lower lids occasionally) and obtain medical attention. If hydrazine is ingested, obtain medical attention immediately. If significant quantities of this compound are inhaled, move the person to fresh air and seek medical attention at once.

In the event of a spill, remove all ignition sources, soak up the hydrazine with a spill pillow or absorbent material, place in an appropriate container, and dispose of properly. Evacuation and cleanup using respiratory protection may be necessary in the event of a large spill or release in a confined area.

Disposal

Excess hydrazine and waste material containing this substance should be placed in an appropriate container, clearly labeled, and handled according to your institution's waste disposal guidelines. For more information on disposal procedures, see Chapter 7 of this volume.

The information in this LCSS has been compiled by a committee of the National Research Council from literature sources and Material Safety Data Sheets and is believed to be accurate as of July 1994. This summary is intended for use by trained laboratory personnel in conjunction with the NRC report Prudent Practices in the Laboratory: Handling and Disposal of Chemicals. This LCSS presents a concise summary of safety information that should be adequate for most laboratory uses of the title substance, but in some cases it may be advisable to consult more comprehensive references. This information should not be used as a guide to the nonlaboratory use of this chemical.