With schools starting up again, classes may be on your mind. But did you know that fires also have classes? Of a different kind than in academia, of course. When we talk about classes of fire, we’re talking about classifications. Fires are classified into different categories based on the type of material that’s burning.
Why Do Fire Classifications Matter?
Understanding what class a fire belongs to is a huge help in fire safety and effective firefighting. For example, if a homeowner or business owner evaluates what types of fire he or she is more at risk for, the right kinds of fire extinguisher can be purchased and at the ready in case of an emergency. Responding to a fire incorrectly – for instance, putting water on a grease fire – can be disastrous.
The 5 Classes of Fires
There are the five main classes of fire. Some are more likely to impact the average person than others, but all are worth knowing about.
Class A
Class A fires are the most common. They involve ordinary combustible, solid materials like wood, cloth, paper, and plastics. When burning, these types of materials produce embers, which can accelerate the fire’s spread. Class A fire extinguishers use water or dry chemicals to cool the fire or interrupt the combustion process.
Class B
Class B fires involve flammable liquids and gases. Some of the ones you’re likely to have in your household are oil, gasoline, propane, or paint. Flammable liquids have intense flames and spread quickly if not effectively smothered by an extinguishing agent such as those expelled by a foam, dry chemical, or carbon dioxide extinguisher. These quell the flames and cut off the oxygen supply that keeps combustion going.
Class C
Class C fires are linked to electrical equipment. Wiring, appliances, circuit breakers, and computers can overheat due to faulty wiring, overloaded circuits, defects, or improper use, or inadequate maintenance. Class C fires present the risk of electrical shock. The solution? Dry chemical or carbon dioxide extinguishers, which do not conduct electricity.
Class D
This class of fires involves combustible metals: magnesium, titanium, sodium, or others. Using water on Class D fires is dangerous, as they can react violently. Instead, they require a special dry powder designed for metal fires, which smothers the flame and separates the metal from oxygen.
Class K
Class K fires involve cooking oils and fats, which is why they’re often associated with kitchens. Oil can burn at high temperatures, so Class K extinguishers contain a wet chemical solution that cools fats and oils and forms a layer that helps prevent re-ignition.
Where Do Chimney Fires Fit?
For those with home fireplaces, chimney fires can be a concern. Knowing how to respond to – and better yet, prevent – chimney fires is important if you want to enjoy using your fireplace safely.
A chimney fire is usually classified as a Class A fire. It meets the markers, as it involves the combustion of solid materials like wood, creosote, and other residues produced by combustion that can accumulate in the chimney. Creosote is highly flammable, and can cause intense fires in a chimney flue if it gets too hot or meets a wayward spark. Chimney fires can also be fueled by nesting materials, leaves, or twigs if a chimney isn’t properly capped.
How Do Chimney Fires Happen?
While other combustibles can enter your chimney, creosote is often a factor. When wood is burned incompletely, creosote is produced. Over time, this tarry substance accumulates on the interior walls of a chimney and becomes a fire hazard.
There are a number of factors that can impact creosote production. For instance, if your chimney is blocked and airflow is restricted, incomplete combustion can result. Burning firewood that’s wet or unseasoned can also lead to increased creosote production. And a chimney that hasn’t been swept for a while is more likely to have higher levels of creosote since chimney sweep technicians carefully remove creosote and obstructions when sweeping a chimney.
What Are the Effects of a Chimney Fire?
Chimney fires have the potential to be quite dangerous. The heat from a chimney fire can cause cracking or structural damage to the chimney itself or surrounding parts of the home. Chimney fires can also spread to the rest of the home, with the potential to cause a full-blown house fire. This risk is amplified if the chimney isn’t lined properly or if combustible materials (such as furniture, curtains, or decor) are too near the chimney.
Chimney fires can also cause carbon monoxide to be released into a home. Carbon monoxide is a colorless, odorless gas that can cause headaches, dizziness, nausea, fatigue, loss of consciousness, or even death.
How Can I Prevent Chimney Fires?
Obviously, no uncontrolled fire in a home is desirable! This includes chimney fires. But just because they occur in a hidden space doesn’t mean they’re entirely out of your control. Following recommended maintenance and burning practices will go a long way in keeping your home and family safe without compromising the use of your cozy home hearth.
- Annual chimney inspections by a certified chimney professional help us identify and respond to potential issues before they become serious problems. This includes identifying ventilation issues, creosote build up, and other issues that may pose risks.
- Routine chimney sweeping will take care of creosote buildup and any other debris that may have found its way into your chimney.
- Burning well seasoned firewood in wood burning appliances will slow the accumulation of creosote – and is simply the only safe fuel to burn.
- Have a chimney cap installed if yours is damaged or missing to keep out animals and debris that could become combustible obstructions.
- Make good ventilation a priority so you have better combustion and hot, clean fires.
- Consider an upgrade to a fireplace insert to improve the efficiency of your fireplace’s burn – and therefore reduce creosote build up.
Reach Out Today
We have a rigorous commitment to fireplace and chimney safety, so if you’re looking for a partner in helping your fireplace perform optimally, look no further! Our experienced technicians are ready to help. Call or reach out online today!