will remain a liquid under-normal atmospheric pressure. Once converted into a liquid, oxygen will remain in its liquid state as long as the temperature is maintained below -297°F. The liquid has an expansion ratio of about 862 to 1, which means that one volume of LOX will expand about 862 times when converted to a gas at atmospheric pressure. Thus, 1 liter of LOX produces about 862 liters of gaseous oxygen. SAFETY PRECAUTIONS As already mentioned, the main dangers of LOX are the extremely low temperature of the liquid, its expansion ratio, and its support of violent combustion. The liquid is nontoxic, but will freeze (burn) the skin severely upon contact. Use extreme caution not to touch implements containing LOX unless gloves are worn. Without gloves, bare skin would immediately stick and freeze to the metal surface. Personnel that could be exposed to accidental spillage of LOX must wear a face shield, coveralls, gloves, and oxygen safety shoes to prevent skin and vision damage. Open gloves, low cut shoes, trousers with cuffs, and similar improper clothing that can form pockets capable of holding a quantity of LOX in contact with the skin present a severe hazard. All personnel handling LOX must wear the protective clothing specified in the protective clothing section of NAVAIR 13-1-6.4. A greater danger than freezing is the combustion supporting potential of oxygen. When LOX is used, it is possible to build up high concentrations of oxygen quickly. Many materials such as cloth, wood, grease, oil, paint, or tar will burn violently when saturated with oxygen, provided an ignition source is supplied. A static electric discharge or spark can serve as an igniter. Once an oxygen-enriched fire is started, it is virtually impossible to extinguish until the oxygen supply is cut off. An added danger exists if a combustible material is saturated with oxygen at low temperatures. Many materials, especially hydro- carbons, tar, etc., will burn with explosive violence when so saturated or subjected to very mild shock or impact. Extreme care must be taken not to splash or spill LOX on clothing. When LOX come in contact with cloth, an ideal and deadly situation for a fire exists—a fire that cannot be put out. LOX by itself will not burn, but mixed with the smallest amount of almost any material will 4-12 cause the liquid to boil and splash violently, making combustion possible. If splashed out of a container, LOX will break into many parts upon contact with the floor\deck. It must be poured slowly from one container to another to avoid splashing, and to allow the gaining receptacle to cool sufficiently without thermal breakage. NEVER seal or cap the vent port of a liquid oxygen system because liquid oxygen at atmospheric pressure will generate up to 12,000 pounds of pressure if allowed to evaporate in a sealed container or system that has no relief provisions. Access to oxygen supply/storage areas should be limited only to personnel familiar with proper handling procedures. The area should be adequately ventilated and free of any materials that could present a fire hazard. All pressure-type containers, plumbing, and pressure-relief devices should conform to the applicable maintenance manual and be kept in good repair. The vents on LOX containers are designed to have a sufficient flow capacity to carry away any oxygen that may boil off in case of accidental loss of insulation. Do NOT cap such vents or cause the opening to be restricted in any way. The pressure relief assembly in LOX system storage vessels consists of a reseatable relief valve and a rupture disc in parallel. The assembly is designed so that the relief valve relieves first, with the rupture disc acting as a safety backup in the event the relief valve malfunctions or its relieving capacity is exceeded. LOX converters and servicing trailers should be stowed or parked so that they are protected from excessive heat and the direct rays of sunlight as much as is practical. All LOX should be segregated from containers of other gases or liquids and all flammable materials. Hydrocarbons such as oil and grease in the xygen handling area could result in death, serious injury, and property damage. Smoking, open flames, or sparks are not ermitted in any oxygen handling area. When transferring oxygen, provide adequate ventilation to prevent the formation of an oxygen enriched atmosphere. Avoid spilling LOX on floors or deck areas. In case of accidental spillage, ventilate the area. Intentional drainage of LOX from a system or container must be caught in a clean drain pan and allowed to evaporate in a suitable open area that will not present a hazard. In the event that LOX is spilled on clothing, separate clothing from skin contact immediately,