Oxygen Hazards: Never Use Oxygen as Air
Oxygen doesn’t burn by itself, but it makes everything else burn much faster and hotter. Clothing, hair and even steel can ignite in oxygen-enriched air. Workers have been killed by using oxygen from a torch outfit to cool off, blow off dust or “freshen” the air in a tank.
- Welders & fabricators
- Maintenance
- Confined space workers
Photo: oxygen cylinder with a warning label: “Use no oil. Never use oxygen as compressed air.”
Never use oxygen to
- Blow dust off clothing, skin or equipment
- Ventilate or “sweeten” a tank, trench or confined space
- Run pneumatic tools or inflate tires
- Cool yourself off
- Start engines or purge lines
Oxygen-enriched air
- Normal air is about 21% oxygen. Above about 23.5% is considered oxygen-enriched and a serious fire hazard.
- Leaking torch hoses or a torch left on in a tank can enrich the air quickly.
- Clothing soaked with oxygen can stay dangerous for a while after you leave the area; air it out before going near a flame or spark.
- Test for oxygen both low and high before and during confined space work. See Confined Spaces.
Oil, grease and oxygen
Oil and grease can explode on contact with high-pressure oxygen. Keep oxygen cylinders, valves, regulators and fittings free of oil and grease. Don’t handle them with oily gloves or hands, and never lubricate oxygen equipment unless with products made for oxygen service.
Safe practices
- Leak-test torch outfits with leak-test solution before use. See Oxy-Fuel Setup.
- Take torches out of confined spaces during breaks, or shut off gas at the cylinders.
- Ventilate confined spaces with clean air from a blower, never with oxygen.
- Store oxygen cylinders at least 20 feet from fuel gas cylinders and combustibles, or separated by a fire-resistant barrier. See Compressed Gas Cylinders.
Standards & references
- 29 CFR 1926.350: Gas welding and cutting, including oxygen
- 29 CFR 1910.146: Permit-required confined spaces (oxygen-enriched atmospheres)
- See also: Inert Gas Asphyxiation
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