Hydrogen, liquified

Formula
H2
Structure
Description
A colorless, odorless cryogenic liquid.
Uses
Oxyhydrogen flame is used in processing of quartz, in production of several metals which resist fusion, such as molybdenum, bismuth.

Registry Numbers and Inventories.
CAS
1333-74-0
EC (EINECS/ELINCS)
215-605-7
EC Index Number
001-001-00-9
EC Class
Extremely flammable
RTECS
MW8900000
RTECS class
Other
UN (DOT)
1049
Merck
12,4833
Beilstein/Gmelin
2 (G)
Swiss Giftliste 1
G-6842
Canada DSL/NDSL
DSL
US TSCA
Listed
Austrailia AICS
Listed
New Zealand
Listed
Korea ECL
Listed

Properties.
Formula
H2
Formula mass
2.02
Melting point, °C
-258.9
Boiling point, °C
-252.8
Vapor density (air=1)
0.07
Critical temperature
-239.9
Critical pressure
12.8
Density
0.071 g/cm3 (liquid, 20 C)
Solubility in water
0.17 mg/100 mL
Viscosity
8.6E-5 P (0 C)
Surface tension
2.126 erg/cm2 (-252.7 C)
Refractive index
1.98
Dielectric constant
1.00 (16.5 C)
Heat of fusion
0.14 kJ/mol
Heat of vaporization
0.98 kj/mol

Hazards and Protection.
Storage
Keep in a cool, dry, dark location in a tightly sealed container or cylinder. Keep away from incompatible materials, ignition sources and untrained individuals. Secure and label area. Protect containers/cylinders from physical damage.
Handling
Containers of this material may be hazardous when emptied. Since emptied containers retain product residues (vapor, liquid, and/or solid), all hazard precautions given in the data sheet must be observed.
Protection
Wear appropriate protective gloves, clothing and goggles. Always wear thermal protective clothing when handling refrigerated/cryogenic liquids.
Respirators
Wear positive pressure self-contained breathing apparatus (SCBA).
Small spills/leaks
Keep sparks, flames, and other sources of ignition away. Keep material out of water sources and sewers. Attempt to stop leak if without undue personnel hazard. Use water spray to knock-down vapors. Do not use water on material itself.
Stability
Stable.
Incompatibilities
Reacts violently with air, oxygen, chlorine, fluorine, strong oxidizers causing fire and explosion hazard. Metal catalysts, such as platinum and nickel, greatly enhance these reactions.
Decomposition
None.

Fire.
Autoignition, °C
500-571
Upper exp. limit, %
76
Lower exp. limit, %
4
Fire fighting
Wear NIOSH/MSHA approved SCBA, flame and chemical resistant clothing. If it can be done without rist, remove material from fire area. Do not extinguish fire unless flow can be stopped. Use water in flooding quantities as fog. Cool all affected containers with flooding quantities of water. Apply water from as far a distance as possible. Do not use water on material itself.
Fire potential
Extremely flammable gas.
Hazards
Burns with an almost invisible flame.
Health
3
 
Flammability
4
 
 
Reactivity
0
 

Health.
Poison_Class
-
Exposure effects
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. Hemiparesis has been reported with volatile substance abuse. Cerebral edema with brainstem herniation may occur. Seizures have been reported following intentional inhalation.
   Ingestion
Frostbite of the lips and mouth may result from contact with the liquid.
   Inhalation
Asphyxiant, headache, drowsiness, dizziness, excitation, salibation, vomiting, unconscious and death.
   Skin
Dermal exposure may cause frostbite injury. Severe tissue burns have been reported.
   Eyes
Decreases in night vision, visual acuity, and visual fields (tunnel vision) may occur. Frothy mucous may be seen.

First aid
 
   Ingestion
Seek medical assistance.
   Inhalation
If victim is unconscious (due to oxygen deficiency), move him to fresh air and apply resuscitation methods; call physician.
   Skin
Rewarming and a variety of topical treatments are indicated for frostbite injury. See main section for more information.
   Eyes
Treat for frostbite.

Transport.
UN number
1049
Response guide
Hazard class
2.1
USCG CHRIS Code
HXX
 
Std. Transport #
4905745