Final answer:
Confined spaces should be ventilated using helium, which is a safe, non-flammable gas that does not support combustion or cause narcotic effects at high pressures like nitrogen.
Step-by-step explanation:
When ventilating a confined space, oxygen should not be used as it presents an increased hazard for flammability. The area should be ventilated with helium. Helium is a non-flammable gas that does not support combustion and is used for filling balloons and lighter-than-air craft. In addition, helium is not a narcotic at high pressures, unlike nitrogen, and is used in oxygen-helium mixtures for deep-sea divers to avoid nitrogen narcosis. It also serves as an inert atmosphere for high-temperature processes like welding, where easily oxidizable metals or sensitive chemical processes are involved. Therefore, helium is a safe and appropriate choice for ventilating confined spaces without introducing additional fire risks.