Which type of fire extinguisher is NOT suitable for paper-based fires?

Type D fire extinguishers are specifically designed for combustible metal fires, which include metals such as magnesium, sodium, and potassium. These materials burn at very high temperatures and can react violently with water or other standard extinguishing agents. Therefore, using a Type D extinguisher would not be effective for fires involving paper, which primarily fall under the category of Class A fires, and are best extinguished with water or Type A fire extinguishers.

In contrast, Type A extinguishers are specifically designed for ordinary combustibles, such as paper, wood, and textiles. They effectively cool the burning material to extinguish the fire. Type B extinguishers are suitable for flammable liquid fires, while Type C extinguishers are meant for electrical fires. Since fire extinguishers are categorized based on the type of material they combat, each has a specific purpose, and using the wrong type can lead to ineffective fire suppression or even exacerbate the situation.