Safety hazards, inert gases

Hazards attendant on use of ethylene oxide in steriliser chambers arise from difficulties in its subsequent removal by evacuation procedures, owing to its ready absorption or adsorption by the treated material. Even after 2 evacuation cycles the oxide may still be present. Safety is ensured by using the oxide diluted with up to 90% of Freon or carbon dioxide. If high concentrations of oxide are used, an inert gas purge between cycles is essential [7], The main factors in safe handling... 

Caution. Tetrahydrofuran is extremely flammable and forms explosive peroxides only freshly distilled, peroxide-free material should be used. Lithium-dispersion is a hazardous material and must be handled in dry conditions and under an inert gas atmosphere. Trimethylchlorosilane and trichloromethylsilane can cause severe skin and eye burns. All manipulations should be carried out in a well-ventilated fume hood protective gloves and safety glasses should be worn. 

Check valves are infrequent on inert gas lines since there is no inherent safety risk if a hydrocarbon (or oxygen) were to flow back to the regulator. Backflow of hydrocarbon to an oxygen cylinder—or vice versa— presents a serious hazard. 

Coauthor Shannon warned that the safety hazard from fire or explosion with hydrogen requires that a hydrogen-inert gas mix be used only below the lower limit of flammability. The lower explosive limit is 4% hydrogen in a hydrogen-air mix. The upper limit is 74.2% hydrogen in an H2-air mix. 

Hence the conditions for the occurrence of an explosion are at times fulfilled in a coal grinding plant. As it is not possible to eliminate deposits of combustible dust inside the plant, the required degree of safety is attainable only by using inert gas for drying and conveying the pulverized coal. In the event of failure of the supply of inert gas a potentially hazardous condition may still arise, so that, theoretically at least, it would be necessary to provide a separate and independent source of inert gas for immediate availability in an emergency. 

DOT CLASSIFICATION 2.2 Label Nonflammable Gas, Oxidizer SAFETY PROFILE A poison. Mildly toxic by inhalation. Prolonged absorption may cause mottling of teeth, skeletal changes. Severe explosion hazard by chemical reaction with reducing agents, particularly when under pressure. A ver dangerous fire hazard a very powerful oxidizer otherwise inert at normal temperamres and pressures. 

---