Oxygen tanks do not explode from the oxygen within them, but they can rupture under extreme conditions. Oxygen is a powerful oxidizer that intensely fuels fires, significantly accelerating combustion. Understanding the associated risks and safety measures is important for preventing serious outcomes.
Understanding Oxygen and Its Storage
Oxygen is a chemical element essential for life, making up about 21% of the air we breathe. In its pure form, it acts as a potent oxidizing agent, readily combining with other elements. This property is fundamental to combustion, enabling rapid chemical reactions that release heat and light.
Medical and industrial oxygen is stored as a compressed gas in robust cylinders, typically made of steel or aluminum. These tanks contain oxygen under high pressure, often 2,000 to 2,200 pounds per square inch (PSI). While designed to safely contain this pressure, proper handling and maintenance are crucial for their integrity.
Why Oxygen Tanks Pose a Hazard
Incidents involving oxygen tanks, such as fires or ruptures, stem from oxygen’s role in intensifying combustion. For a fire to occur, three elements must be present: an oxidizer (oxygen), fuel, and an ignition source. Removing any one of these components can prevent or extinguish a fire.
In an oxygen-enriched environment, materials that might not easily burn in ambient air can ignite readily and burn with extreme intensity. This means nearly any combustible material can become a significant fuel source in the presence of concentrated oxygen.
Common fuels that react dangerously with oxygen include oils, greases, flammable liquids, dust, and even certain metals like stainless steel or aluminum. Hydrocarbon-based substances, such as petroleum products, are particularly hazardous and should never contact oxygen or oxygen-handling equipment. Contamination by small particles like metal shavings or dust can also act as fuel.
Various ignition sources can trigger an incident. These include open flames, sparks from electrical equipment or static electricity, and heat generated by friction or rapid pressurization. For instance, opening an oxygen cylinder valve too quickly can cause a sudden pressure increase (adiabatic compression), generating enough heat to ignite contaminants or regulator components. If an oxygen tank is exposed to extreme heat, such as from an external fire, internal pressure can rise significantly. This can exceed the tank’s structural limits or overwhelm its pressure relief mechanisms, leading to a catastrophic rupture.
Preventing Incidents with Oxygen Tanks
Preventing incidents with oxygen tanks involves strict safety protocols for handling and storage. Oxygen cylinders should always be stored upright and secured, such as with chains or straps, to prevent falls. They must be kept away from heat sources, direct sunlight, and flammable materials, ideally separated by at least 20 feet or a fire-rated barrier.
Proper handling is essential to avoid mechanical damage or contamination. Tanks should never be dropped, dragged, or subjected to impacts, as this can damage the valve, potentially turning the cylinder into a dangerous projectile. Hands and equipment must be clean and free of oils, greases, or other flammable substances before handling oxygen tanks, regulators, or fittings. Only equipment specifically designed and “cleaned for oxygen service” should be used, ensuring the absence of combustible contaminants.
Adequate ventilation is necessary where oxygen tanks are stored or used to prevent oxygen-enriched atmospheres, which increase fire risk. It is also important to “crack” the cylinder valve briefly before attaching a regulator to clear dust or debris that could act as an ignition source. Smoking and open flames must be strictly prohibited near oxygen tanks, with “No Smoking” signs clearly posted.
Responding to an Oxygen Tank Emergency
In an oxygen tank incident, such as a fire or leak, prioritize personal safety and immediately evacuate the area. Once at a safe distance, contact emergency services, providing clear details about the situation and location. Informing them about the presence of oxygen tanks is important for their response.
If safe to do so, and without putting oneself at risk, shut off the oxygen supply at the cylinder valve. This can help stop or reduce oxygen flow, potentially limiting fire intensity. However, never attempt this if it means entering a hazardous environment or if there is any doubt about safety.
Water is generally ineffective and potentially dangerous for extinguishing oxygen-fed fires, especially those involving flammable liquids, as it can spread burning material. Water primarily cools and smothers fires, but it does not remove the oxygen fueling combustion. For oxygen-related fires, specialized fire extinguishers or professional responders are needed. Any incident involving an oxygen tank should be reported to the supplier for investigation and proper equipment management.