Technically, an explosion can occur without oxygen. For example, in outer space, exploding stars (“supernovas”) are caused by nuclear and gravitational forces.
Our explosion injury lawyers have also handled gas pressure explosions, which occur in things like boiler explosions and pressurized loading arm explosions. Those do not necessarily require outside oxygen either.
Most work injury explosion cases, however, involve a chemical reaction and burning. Those generally require outside oxygen or an oxidizer, and sometimes both.
An oxidizer accepts or “strips” electrons from another substance. This can release energy and cause ignition in and of itself. More frequently, oxidizers accelerate combustion—making the combustion event worse, more expansive, faster, or all of the above.
As is discussed above, generally, if any of the three legs of the “fire triangle” are broken, a fire or explosion typically cannot occur. A properly planned work operation typically involves eliminating as many of the three legs as is possible. Many people are surprised to learn that, oftentimes, oxygen is the easiest of the three legs to eliminate. For example, in a petroleum service operation, sometimes there will necessarily be a fuel source (the oil or gas product) present. A well-planned and safe operation may require oxygen to be eliminated from the process, as well as the ignition source. For example, a vacuum truck offloading operation or a refinery tank cleaning operation may be conducted safely through the use of a nitrogen blanket, which removes oxygen from the process.