Normally, air contains 21 per cent oxygen and oxygen is essentially nontoxic. No health effects have been observed in people exposed to concentrations up to 50 per cent liquid oxygen at one atmosphere pressure for 24 hours or longer. Inhalation of 80 per cent oxygen at one atmosphere for more than 12 hours can cause irritation of the respiratory tract, nausea, dizziness, muscle twitching, vision loss, coughing, nasal stuffiness, sore throat and chest pain. A characteristic neurological syndrome can be observed when pure oxygen is inhaled at pressures greater than two or three atmospheres.
Characteristic epilepsy-like convulsions, which may be preceded by visual disturbances such as loss of peripheral vision, also occur. Continued exposure can cause severe convulsions, leading to death. The effects are reversible after reduction of oxygen pressure. Some common materials like asphalt, kerosene, cloth, wood, paint, tar and dirt containing oil or grease can react violently with liquid oxygen at certain pressures and temperatures. Personnel must be thoroughly familiar with properties and safety considerations before being allowed to handle liquid oxygen and its associated equipment.
We are a voice to you; you have been a support to us. It is usually stored in large tanks that are kept well insulated from heat in order to keep the oxygen from evaporating. The primary use of liquid oxygen is in rocket propulsion systems; however, many hospitals and other health care facilities store oxygen in liquid form and convert it to gas as needed. Liquid oxygen is an extremely concentrated substance. While it is not flammable, it accelerates combustion.
Its volatility requires it to be mixed with ozone or other gases to stabilize it before it can be used for propulsion. Liquid oxygen is especially dangerous when it comes in contact with organic substances.
The chances of an explosion are high if liquid oxygen spills on asphalt. Liquid oxygen will accelerate combustion if it comes in contact with oil or grease. This presents an additional hazard if it is spilled on asphalt; vehicles passing over the asphalt may leak oil or grease and contribute to a fire. When liquid oxygen spills, it vaporizes into the air, as the atmosphere is far too warm to support it in liquid form. As it vaporizes, it creates a dense cloud of concentrated oxygen.
The cloud will infect the clothes of anyone passing through it with concentrated oxygen. Many organic materials can react explosively, especially if a flammable mixture is produced. Clothing splashed or soaked with liquid oxygen can remain highly flammable for hours.
Without adequate venting or pressure-relief devices on the containers, enormous pressures can build up. Unusual or accidental conditions such as an external fire, or a break in the vacuum which provides thermal insulation, may cause a very rapid pressure rise. The pressure relief valve may not be able to handle this increased pressure.
Therefore, the containers must also have another backup device such as a frangible bursting disc. Add a badge to your website or intranet so your workers can quickly find answers to their health and safety questions. Although every effort is made to ensure the accuracy, currency and completeness of the information, CCOHS does not guarantee, warrant, represent or undertake that the information provided is correct, accurate or current. CCOHS is not liable for any loss, claim, or demand arising directly or indirectly from any use or reliance upon the information.
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Search all fact sheets: Search. Type a word, a phrase, or ask a question. Each cryogenic liquid has its own specific properties but most cryogenic liquids can be placed into one of three groups: Inert Gases : Inert gases do not react chemically to any great extent. They do not burn or support combustion. Examples of this group are nitrogen, helium, neon, argon and krypton.
Flammable Gases : Some cryogenic liquids produce a gas that can burn in air. The most common examples are hydrogen, methane and liquefied natural gas. Oxygen : Many materials considered as non-combustible can burn in the presence of liquid oxygen.
Organic materials can react explosively with liquid oxygen. The hazards and handling precautions of liquid oxygen must therefore be considered separately from other cryogenic liquids. Liquid Dewar Flasks Liquid dewar flasks are non-pressurized, vacuum-jacketed vessels, somewhat like a "Thermos bottle".
Laboratory Liquid Dewar Flasks Laboratory liquid dewars have wide-mouthed openings and do not have lids or covers. Liquid Cylinders Liquid cylinders are pressurized containers specifically designed for cryogenic liquids. There are three major types of liquid cylinders which are designed for dispensing: liquid or gas only gas only liquid. Extreme Cold Hazard Cryogenic liquids and their associated cold vapours and gases can produce effects on the skin similar to a thermal burn.
Asphyxiation Hazard When cryogenic liquids form a gas, the gas is very cold and usually heavier than air. Toxic Hazards Each gas can cause specific health effects. Fire Hazard Flammable gases such as hydrogen, methane, liquefied natural gas and carbon monoxide can burn or explode.
Oxygen-Enriched Air Liquid hydrogen and liquid helium are both so cold that they can liquefy the air they contact.
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