The primary hazard during Class K fire suppression is:

• A. Electrical shock
• B. Toxic gas release
• C. Smoke inhalation
• D. Re-ignition of fats and oils

Answer: (D)

Fats and oils in a Class K fire store a lot of heat, so even after the flames are knocked down, hot oil can remain ready to reignite if cooling isn’t thorough. The wet chemical extinguishing agent used for Class K fires works by saponifying the fats and forming a soapy layer that cools the surface and helps separate the oil from oxygen. This greatly reduces the chance of re-ignition, but it isn’t a guarantee—if pockets of hot oil persist or cooling is incomplete, a flare‑up can occur once the initial flames appear to be out.

Electrical shock and toxic gas release can occur in some fires, but they aren’t the specific ongoing hazard being addressed during suppressing a grease fire. Smoke inhalation is a general risk in fires, but the most critical suppression-specific hazard here is the potential for the hot fats and oils to reignite.