Oxygen gas is a powerful oxidizer that dramatically changes how other materials burn. While not flammable itself, oxygen can accelerate combustion and turn a minor spark into an intense fire. Safe storage requires controlling the physical environment, preventing contact with incompatible substances, securing cylinders, and performing regular checks for leaks. Since compressed oxygen is stored under high pressure, often exceeding 2,000 pounds per square inch, any breach can result in catastrophic failure.
Establishing a Safe Storage Environment
Oxygen storage locations must be carefully controlled to minimize environmental risks. Cylinders should be kept in a well-ventilated area, allowing potential gas leaks to dissipate quickly. Placing cylinders in confined spaces, such as closets or car trunks, is hazardous because a leak rapidly creates an oxygen-enriched atmosphere.
Temperature regulation is necessary for safe storage, as excessive heat increases the internal pressure of the cylinder. Oxygen cylinders must never be exposed to temperatures exceeding 125 degrees Fahrenheit (52 degrees Celsius). If stored outdoors, cylinders require protection from direct sunlight and the elements to prevent corrosion and temperature fluctuations.
Cylinders must be stored in designated locations that do not interfere with building safety or movement. Storage areas should not obstruct exit routes, stairways, or gangways, ensuring they do not impede emergency evacuation. Racks or supports used in the storage area should be constructed of noncombustible materials to prevent them from contributing to a fire.
Protecting Against Ignition and Contamination
The primary chemical risk comes from oxygen’s ability to react violently with common organic materials. Oil, grease, and petroleum-based products are highly incompatible with high-pressure oxygen and can spontaneously ignite or explode upon contact. Therefore, all equipment, including valves, regulators, and fittings, must be kept scrupulously clean and free of hydrocarbon residue.
A minimum separation distance must be maintained between oxygen and potential ignition sources. Smoking, open flames, and electrical heating elements should be prohibited within at least 20 feet of the storage location. This rule applies to oxygen stored both indoors and in exterior enclosures.
As an oxidizer, oxygen must be separated from flammable gases and other combustible materials, such as solvents, paints, and fuel tanks. Separation is achieved by maintaining a minimum distance of 20 feet between the oxygen and combustible items. Alternatively, a noncombustible barrier at least five feet high with a fire-resistance rating of at least a half-hour can segregate the storage areas.
Physical Security and Proper Handling of Cylinders
Physical security of high-pressure cylinders is paramount because a falling tank can shear off its valve, turning the cylinder into an unguided projectile. All oxygen cylinders, whether full or empty, must be secured upright using chains, straps, or a purpose-built stand. Cylinders should be placed where they cannot be damaged by passing equipment or falling objects.
When a cylinder is not connected for use, the valve protection cap must remain securely in place. This cap protects the valve assembly from physical damage that could result in a dangerous release of gas. When moving cylinders, they should never be rolled, dragged, or slid across the floor.
Cylinder movement should be performed using a cart, hand truck, or trolley specifically designed for transporting compressed gas cylinders. Even empty cylinders must be handled with caution, as they still contain residual pressure and pose a mechanical hazard. Lifting a cylinder by its valve cap should be strictly avoided.
Routine Inspection and Leak Detection
Ongoing maintenance and routine inspection are necessary to ensure the integrity of oxygen equipment and connections. This involves regularly checking for leaks at the valve and regulator connections. Leaks are detected by applying a leak test solution to all joints and looking for the formation of bubbles, which indicates escaping gas.
While mild soap solution has been traditionally used, it is not recommended for oxygen service because some soaps contain animal fats or petroleum-based ingredients. These residues can remain on fittings and react explosively in a high-pressure oxygen environment. Users should employ a commercial leak detection solution specifically certified as safe for use with oxygen.
Beyond leak checks, the cylinder requires a visual inspection for signs of damage, such as deep dents, rust, or gouges in the metal. Regulator gauges should be checked to ensure they function correctly and that cylinder pressure is maintained when the main valve is closed. Liquid oxygen (LOX) containers, which store the gas at cryogenic temperatures, must be stored upright to allow for necessary venting of vapor to maintain safe internal pressure.