Extinguishers3 min read
The Class K fire extinguisher in a commercial kitchen
Where the Class K fire extinguisher goes, how many a kitchen needs, and how it works alongside the hood system over your cooking line.
A Class K fire extinguisher is the hand-held extinguisher made for fires in cooking oil and grease. In a commercial kitchen it hangs near the cooking line as the backup to the hood system over the appliances. Where the cooking uses oil or fat, the fire code calls for one.
What a Class K extinguisher is for
Class K units are wet chemical fire extinguishers, built for one kind of fire: cooking oil and fat in fryers and other commercial cooking equipment. They put out and cool that kind of fire better than other types of extinguisher.
An ordinary dry chemical extinguisher is not enough for a fire in vegetable cooking oil, because that kind of fire can flare up again.
How it works with the hood system
The hood system is the first line of protection. It sits over the appliances and goes off automatically. When it does, it shuts off the gas or electric supply to the cooking equipment underneath.
The Class K extinguisher is the backup. If there is a fire on the cooking line, the order is:
- Activate the hood system. If it has not gone off on its own, use its manual release.
- Then use the Class K extinguisher.
The fire code calls for a sign beside each Class K extinguisher that gives the same instruction.
The hood system has its own service schedule: a full maintenance inspection every six months, and a pressure test of its cylinder (a hydrostatic test) every twelve years. We cover that under commercial kitchen fire suppression system service. We also cover fire protection for restaurants and hospitality.
Where it goes and how many you need
A Class K extinguisher has to be within a 30-foot walk of the cooking equipment it protects.
How many you need depends on the fryers. Under the International Fire Code, one Class K extinguisher of at least 1.5 gallons covers up to four fryers holding up to 80 pounds of oil each, with one more for every additional group of four. For a single fryer larger than six square feet in surface area, the extinguisher maker's recommendations set the number instead.
Where each extinguisher hangs, and whether it is the right type for what it protects, are part of what we check when we service the extinguishers in a building.
Keeping it in service
A Class K extinguisher is checked and serviced on these intervals:
- Every month. A quick visual check that it is in place, nothing is blocking it, the pressure is in range and the seal is intact. Your own staff can do this. Keep a record that it happened.
- Every year. Hands-on maintenance by a technician, and a new tag.
- Every five years. A hydrostatic test, where the cylinder is pressure-tested. Wet chemical cylinders are on a five-year cycle. Dry chemical cylinders are on a twelve-year one.
- After any use. It is recharged, checked and re-tagged before it goes back on the wall.
The tag on the extinguisher records the yearly service and any recharge. If you have not looked at one closely, here is how to read a fire extinguisher inspection tag.
If you are not sure whether the kitchen has the right extinguisher in the right place, tell us what is installed and we will confirm what applies. We handle Class K and other portable fire extinguisher service and the hood system, and both sit alongside everything else in the building on one inspection calendar.
Q&A
What is a Class K fire extinguisher used for?
Fires in cooking oils and fats, the kind that start in fryers and other commercial cooking equipment. It uses a wet chemical agent made for that kind of fire. In a commercial kitchen it is the backup to the hood system over the cooking line.
What fire extinguisher do I need for a commercial kitchen?
At the cooking line, a Class K extinguisher, wherever the cooking uses oil or fat. An ordinary dry chemical extinguisher is not enough for a fire in vegetable cooking oil, because that kind of fire can flare up again.
Do I still need a Class K extinguisher if the kitchen has a hood system?
Yes. Where the cooking uses oil or fat, the fire code calls for a Class K extinguisher in addition to the hood system. The hood system is the first line of protection, and the extinguisher is the backup.
When should you use a Class K fire extinguisher?
After the hood system. If it has not gone off on its own, activate it with its manual release, then use the Class K extinguisher. The fire code calls for a sign beside each Class K extinguisher that gives the same instruction.
Where should a Class K fire extinguisher be placed?
Within a 30-foot walk of the cooking equipment it protects. Where each extinguisher hangs, and whether it is the right type for what it protects, are part of what we check when we service the extinguishers in a building.
How many Class K extinguishers do I need for my fryers?
Under the International Fire Code, one Class K extinguisher of at least 1.5 gallons covers up to four fryers holding up to 80 pounds of oil each, with one more for every additional group of four. For a single fryer larger than six square feet in surface area, the extinguisher maker's recommendations set the number.
How often is a Class K extinguisher serviced?
It gets a visual check every month, hands-on maintenance and a new tag once a year, and a pressure test of the cylinder (a hydrostatic test) every five years. It is also recharged and re-tagged after any use.