What is the most common gas used for plasma cutters in the fire service?

The most common gas used for plasma cutters in the fire service is air. Plasma cutting involves creating an electrical arc between an electrode and workpiece that ionizes the gas, turning it into plasma. Air is often preferred because it is readily available, cost-effective, and provides good cutting capabilities for various metals.

Using air as the gas helps to achieve a high-temperature arc that can quickly melt through materials. While other gases like argon, oxygen, and nitrogen can also be utilized in specialized applications, they are typically more expensive or may not provide as efficient cutting characteristics as air for general use in the fire service.