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.
For the full kitchen walkthrough (why ABC fails on grease, the sizing math by fryer count, mounting heights, monthly checks, and the placard) see our Class K fire extinguisher guide.
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.
