Safety Rules for Cryopreparation

As is often the case in every day life, the main risk in the routine use of cryopreparation methods is frequently due to inadequate knowledge or underestimation of the hazards. Vapourization of larger quantities of nitrogen in badly ventilated, small rooms or cool rooms may be lethal (Sect. 2). The same applies to explosive propane/air mixtures (Sect. 3). Eyes and skin may be severely damaged by secondary cryogen splashing, e.g. liquid propane, ethane or halogenated hydrocarbons (Sect. 4). The problems presented by primary cryogen splashing, e.g. liquid nitrogen (LN2) or liquid helium (LHe) are completely different (Sect. 5). Finally, precautions should be taken when working with inflammable, secondary cryogens and when using glass containers or vessels of materials which become brittle at cryogenic temperatures (Sects. 6 and 7). Transport and removal of cryogens require particular safety measures (Sect. 8).