How does moisture content affect fire risk?

Higher moisture content in materials can significantly reduce their combustibility and fire risk because moisture acts as a barrier to ignition and slows the spread of fire. When materials contain a higher percentage of water, the energy from the fire must first evaporate the water before increasing the temperature of the material sufficiently for combustion to occur. This process can delay ignition and decrease the intensity of a fire, making it less likely for the material to catch fire easily.

Additionally, wet or moisture-laden materials tend to require more energy (heat) to ignite compared to their dry counterparts. In various scenarios, especially in residential or industrial settings, moisture can absorb heat and limit the amount of thermal energy that can effectively raise the material's temperature to its ignition point. Thus, by understanding the relationship between moisture content and fire behavior, one can better assess and manage fire risks in different environments.