Class K Extinguishers
Class K fire extinguishers use a wet chemical agent, typically a potassium acetate, potassium carbonate, and/or potassium citrate solution, designed for cooking oil, vegetable fat, and animal fat fires in commercial kitchens. The agent saponifies hot oil into a soap-like foam blanket that smothers vapors and cools the surface below auto-ignition. NFPA 96 (2024 edition) Chapter 10, Fire-Extinguishing Equipment, requires Class K portables wherever solid-fuel, vegetable-oil, or animal-fat cooking operations exist. The portable works alongside a pre-engineered hood suppression system over the cookline.
The portable unit is listed to UL 711 (Rating and Fire Testing of Fire Extinguishers) and ANSI/UL 8 (the wet chemical extinguisher standard). The UL 300 hood suppression system has its own separate listing. The hood is the primary defense: it discharges automatically when its fusible link releases. The portable gives a crew member a backup tool to finish the job or handle a fire that escapes the hood's coverage. Pre-engineered wet chemical hood systems are governed by NFPA 17A.
Never substitute an ABC or CO2 extinguisher on a grease fire. ABC dry chemical lacks the cooling capacity to drop oil below auto-ignition and can spray flaming oil out of the appliance, and no dry-chemical agent has passed UL 300 testing. CO2 cools the surface but allows re-ignition once the oil warms back up.
Placement and signage
NFPA 10 (2022 edition) Chapter 6, section 6.6 (Installations for Class K Hazards) sets a maximum 30-foot travel distance from any cooking appliance producing grease-laden vapors to the nearest Class K portable. NFPA 10 section 5.5.4.5.3 requires a placard near the extinguisher noting that the fixed suppression system must be activated before the portable is used.
Which Buckeye Class K for your kitchen
| Model | UL Rating | Best for | Discharge |
|---|---|---|---|
| 6 L Wet Chemical (1.59 gal) | 1-A:K | Single-cookline, food truck, small restaurant | ~54 sec |
| 2.5 Gal Wet Chemical (9.6 L) | 1-A:K | Multi-station commercial, banquet, institutional | ~73 sec |
Both units share the 1-A:K UL rating. The larger 2.5 gallon model buys more discharge time and a wider effective area, not a higher numeric rating. Both are manufactured by Buckeye Fire Equipment in Kings Mountain, NC.
