Grease Vapors and Accumulation: How Dangerous are They Really?

Kitchen hood cleaning services from grease buildup

There is more than one way for a kitchen fire to erupt. When you heat cooking oil in a pan on the stove, it has to reach a specific high temperature before it can possibly ignite and catch fire. This is because the cooking oil itself does not burn, it is the vapor it emits that has reached its boiling point and can now ignite.

Properties of Grease Vapors

The flash point of a flammable liquid is the lowest temperature at which it can form an ignitable mixture in the air. There must still be an ignition source in order for a fire to happen, but usually, this ignition source is the source of heat that is heating the oil, which is the gas burner, electric stove or deep fryer.

This ignition source has to be hotter than the oil to reach the fire point. The fire point is the temperature that must be reached for a vapor to continue to burn after ignition. The oil vapor will need a continued source of heat at a certain temperature to continue burning. For the fire to be self-sustaining, the temperature must be a little hotter than the initial flash point.

When a fire starts on a stovetop and then reaches the kitchen exhaust system vents, vents that have not been cleaned in some time, this fire has all the fuel it needs to keep burning. Grease residue is combustible at approximately 700 degrees Fahrenheit. Flare-ups from grills or deep fryer malfunctions can reach these temperatures easily. If the cook line catches fire and the ductwork in your kitchen exhaust system hasn’t been properly maintained, this could present an incredible fire hazard.

Grease Accumulation in Your Vents

When you neglect to have your kitchen exhaust system cleaned on a regular basis, you’re allowing grease vapors to collect and solidify in your exhaust vents. Grease vapor accumulation is a natural outcome for kitchen exhaust systems. But it is the responsibility of the commercial kitchen owner to limit and manage this grease buildup. Hood filters are an important component, helping to limit the amount of grease that makes it into the ductwork and exhaust fan, but deposits do collect over time regardless.

These grease deposits must be removed to prevent this potential fire hazard. The only way to guarantee an entirely safe and operable kitchen exhaust system is through complete removal of all grease buildup. Most vendors in the industry today can’t provide the thorough cleaning necessary for a completely safe system. Current fire code allows for the tagging of “inaccessible areas” by vendors that cannot reach certain corners or areas of the ductwork. This leaves room for ignitable grease to pool in these areas, increasing your risk of fire. Bare Metal Standard refuses to allow inaccessible areas by our cleaning technicians and provides a bare metal clean every time, guaranteed. We do this because we care about fire safety and the livelihood of commercial kitchen owners and operators.

The picture below shows a code compliant “inaccessible area.” All that grease could absolutely result in a very destructive structure fire for a restaurant or other commercial kitchen. It would extremely difficult to contain a grease fire with that much fuel at its disposal.

An air duct system caked in solidified grease.

We at Bare Metal Standard never cut corners. We truly believe in the safety of our communities and businesses and work to ensure that our proprietary cleaning methods ALWAYS clean to 100% of your kitchen exhaust system. You will never see ductwork like that shown above after a routine kitchen exhaust cleaning by a Bare Metal Standard cleaning technician. Rest assured that when you partner with your local Bare Metal Standard, you’re making the best decision for the maintenance and safety of your commercial kitchen exhaust system.