What is one reason oxygen must be handled with care in welding applications?

Oxygen must be handled with care in welding applications primarily because it can react violently with organic oils. When oxygen is present in high concentrations and comes into contact with oils, greases, or other organic materials, it can promote rapid combustion or even an explosion. This is particularly pertinent in welding environments, where equipment and surfaces may be contaminated with such substances. The high reactivity of oxygen with flammable materials poses significant safety hazards, making it crucial for welders to ensure that work areas and equipment are free from oils and other potential fire hazards prior to using pressurized oxygen. Proper training and safety protocols help to mitigate these risks, ensuring a safer welding environment.