Which of the following materials is NOT typically found in Class K fires?

Class K fires are specifically associated with combustible cooking oils and fats commonly found in commercial kitchens. This classification includes materials like oils, fats, and greases, which are more prevalent in cooking processes and can ignite under certain conditions, leading to hazardous fire situations.

Wood, while flammable, does not fall under the Class K category, as it is typically associated with Class A fires, which involve ordinary combustibles like wood, paper, and cloth. Class K focuses on the unique nature of fires involving cooking materials that require specialized extinguishing agents, such as wet chemical fire extinguishers, which are designed to cool and emulsify the burning oils and fats, preventing re-ignition.

Thus, the presence of wood, while it can catch fire, is not a typical component of Class K fires, making it the correct answer.