Liquid hydrogen cold burns

Cold "Burns" (8). Direct contact of body tissue with liquid hydrogen for a short time may result in no damage because the boiling liquid will be separated from the skin by a layer of vapor and because hydrogen has a relatively low heat of vaporization. Cold gas jetting onto the skin can result in a high heat flux sufficient to cause freezing. The body can tolerate heat fluxes of 30 Btu/hr-ft without discomfort a flux of 740 Btu/hr-ft will freeze facial tissue in about 10 seconds. A... 

The product obtained is a colourless oil. This is washed with water, then drived over calcium chloride and fractionated. Tripropylsilicane distils between 170° and 175° C. the residue is tetrapropylsilicane. Tripropylsilicane is a colourless, pungent, fuming liquid, and burns with a luminous, sooty flame. It boils at 170° to 171° C., density 0 7723 at 4° C., 0 7621 at 15° C., and is difficult to free from the tetrapropyl body. To prevent decomposition it should be distilled in a stream of hydrogen. The compound is easily soluble in alcohol or ether, but insoluble in water or concentrated sulphuric acid. With the latter, however, feeble oxidation occurs in the cold, with evolution of sulphur dioxide, and on warming tripropylsilicon oxide is formed. 

Liquid hydrogen is a very cold material, -423°F (-252.8°C). Contact with human body tissue can result in severe burns, destroying tissue almost like the burn from a flame. 

Liquid hydrogen and the cold gas evolving from the liquid can produce severe cryogenic burns similar to thermal burns upon contact with the skin and other tissues. The eyes can be injured by exposure to the cold gas or splashed liquid that would otherwise be too brief to affect the skin of the hands or face. Contact between unprotected parts of the body with uninsulated piping or vessels containing liquid hydrogen can cause the flesh to stick and tear when an attempt is made to withdraw. 

Knowledge of the Hazards. Adequate knowledge of each of the hazards associated with handling hydrogen in any form allows all needed safety practices to be fully implemented. These hazards have been identified as related to flammability, expansion from liquid to gas in confined spaces, improper materials of construction, cold "burns," and breathing atmospheres con-... 

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