Part of a group of extinguishers known as "clean agent" extinguishers, CO2 (or Carbon Dioxide) extinguishers are another common extinguisher. They are called "clean agent" because, unlike dry chemical, when you use a clean agent extinguisher, the fire extinguishant evaporates on its own. This process leaves little-to-no extra cleanup for the operator.
CO2 extinguishers cover Class B and Class C fires. They typically come in 5 lbs, 10 lbs, 15 lbs, or 20 lbs sizes, but can be purchased at sizes up to 100 lbs. Extinguishers at 50 lbs or heavier are typically on wheels.
CO2 extinguishers are non-corrosive and non-conductive. CO2 extinguishers are not recommended for open-air locations, as the chemical will disperse in the wind. Additionally, caution is advised when using CO2 in small, enclosed spaces, as carbon dioxide can start replacing the oxygen in a room. After extinguishing the fire, ventilate the area well to prevent suffocation.