Liquid carbon dioxide (CO2) is not commonly used as a firefighting agent to extinguish forest fires due to several reasons:
Availability and logistics: Liquid CO2 is not readily available in large quantities and is not typically stored or transported for firefighting purposes. It is primarily used in industrial applications, such as food freezing, carbonation of beverages, or as a coolant in certain processes. The infrastructure and logistics required to deploy and distribute liquid CO2 for firefighting would be impractical for most firefighting scenarios.
Evaporation and limited range: Liquid CO2 has a low boiling point of -78.5 degrees Celsius (-109.3 degrees Fahrenheit). When exposed to ambient temperatures, liquid CO2 rapidly evaporates and converts into a gaseous state, which limits its range and effectiveness as a firefighting agent. The gaseous CO2 produced by the evaporation may not have sufficient reach to cool the burning material or block the fire from oxygen.
Lack of smothering effect: While CO2 is known as an extinguishing agent for certain types of fires, such as flammable liquid fires or electrical fires, it is not as effective for controlling or extinguishing large-scale forest fires. Forest fires involve burning vegetation and other organic materials, which can continue to produce flammable gases and embers. The limited range and rapid evaporation of CO2 may not effectively smother the fire or block the necessary oxygen supply.
Safety concerns: The use of liquid CO2 in firefighting operations can introduce safety concerns. The extreme cold temperature of liquid CO2 can cause thermal shock and damage to living organisms or delicate ecosystems. Additionally, the release of large quantities of CO2 into the environment can displace oxygen and create an asphyxiation hazard for humans and wildlife.
Instead of liquid CO2, firefighting agencies typically employ other methods and materials specifically designed for forest fire suppression. These may include techniques such as water application, fire retardants, foam, or specialized firefighting equipment like helicopters or firebreak construction. These methods are more practical, readily available, and suitable for controlling and extinguishing forest fires.