- Helium, compressed
A colorless, odorless, tasteless gas. It is chemically inert. When shipped as a liquid it is very cold and will solidify all other gases. UN(DOT) number and guide are for the cryogenic liquid.
Diluent for gases, liquid helium is used for production of low temperature, inert, nonflammable gas used for balloons & airships, in lasers, nucleonics & rocket research.
Registry Numbers and Inventories.
Swiss Giftliste 1
Melting point, °C
Boiling point, °C
Vapor pressure, mmHg
1560 (-268 C)
Vapor density (air=1)
0.176 g/L (25 C)
Solubility in water
0.096 erg/cm2 (-268 C)
1.035 - 1.1811 (25 C) pressure dependent
0.00366/K at 0 C
Heat of vaporization
Hazards and Protection.
Cylinders should be stored and used in dry, well ventilated areas, away from heat sources.
Handle in accordance with all current regulations and standards.
Wear appropriate protective gloves, clothing and goggles. Always wear thermal protective clothing when handling refrigerated/cryogenic liquids.
Wear positive pressure self-contained breathing apparatus (SCBA).
Attempt to stop leak if without undue personnel hazard.
Stable at room temperature and pressure.
Extinguish fire using agent suitable for type of surrounding fire. (Material itself does not burn.) Cool all affected containers with flooding quantities of water. Apply water from as far a distance as possible.
Containers may explode when heated. Ruptured cylinders may rocket.
Rapid breathing and rapid heart rate are common. In severe cases abnormally low blood pressure, apnea, and cardiac arrest develop. Various disturbances including headache, dizziness, mood disturbances, numbness of the extremities, sleepiness, mental confusion, poor judgement and coordination, and memory loss may occur. Prolonged or severe hypoxia results in unconsciousness. Prolonged asphyxia may produce CNS injury.
Unlikely route of exposure.
Hyperventilation may develop. Vapors may cause dizziness or asphyxiation without warning.
Contact with gas is not expected to cause problems unless at low temperature. At low temperature, frostbite may be observed.
Decreases in night vision, visual acuity, and visual fields (tunnel vision) may occur. Frothy mucous may be seen.
Seek medical assistance.
Administer 100% humidified supplemental oxygen with assisted ventilation as required. If hypoxia has been severe or prolonged, carefully evaluate for neurologic sequelae and provide supportive treatment as indicated.
Rewarming and a variety of topical treatments are indicated for frostbite injury. See main section for more information.
Irrigate exposed eyes with copious amounts of tepid water for at least 15 minutes. If irritation, pain, swelling, lacrimation, or photophobia persist, the patient should be seen in a health care facility.
Std. Transport #