The air we breathe contains by volume 78% nitrogen, 21% oxygen and approximately 1% argon. Oxygen concentrations as high as 23% are considered acceptable by OSHA. However, in many areas of industry and medicine where technical or high-purity oxygen is used, oxygen concentrations can exceed 23% and create what is known as “flammable atmosphere,” leading to serious accidents and the inability for workers to self-rescue from hazardous situations when proper care is not taken.
Oxygen is non-flammable, but it is a fire promoter and can accelerate combustion and thus is a hazardous substance. Ignition may be caused by sparking, welding or using electric tools when concentrations rise above 23%. Materials of construction, education and testing go far to prevent these hazards in industrial settings.
Click here to read more.