What is the foam proportioning percentage for Class D fires?

The foam proportioning percentage for Class D fires is essential for effectively extinguishing fires involving combustible metals, such as magnesium, titanium, and sodium. In the context of Class D fires, the correct proportioning percentage is critical for ensuring that the foam blanket effectively inhibits the combustion reactions that occur with these metals.

Class D fires require specific suppression techniques due to the unique behaviors of combustible metals when they come into contact with water and other forms of conventional firefighting methods. The use of specialized foam, which is proportioned correctly, helps to smother the fire and prevent the release of flammable metal oxides, thus reducing the risk of re-ignition.

The percentage range of 3% to 6% for foam proportioning indicates that a stronger concentration is necessary compared to some other fire classes. This higher proportion of foam allows for the creation of a thicker foam blanket that can effectively cover the burning metals and exclude oxygen, which is crucial for extinguishing the fire without exacerbating the situation.

In summary, the correct answer reflects the need for a higher concentration of foam for Class D fires to effectively manage the risks presented by combustible metals, ensuring firefighter safety and fire control.