The fire extinguisher has proven to be one of the most powerful fire retardants that man has invented. However, there are other alternatives that can also help put out fire, such as sand. Find out which one is better for putting out fires below.
Sand Chemical Formula
There are many types of sand, so no one chemical structure covers all of them. However, the most common material that makes up sand is silica, or silicon dioxide, which has a chemical formula of SiO₂. This is formed by a covalent bond between Silicon (Si) and Oxygen (O).
Quartz makes up most silicon dioxide used in sand. Other materials that make up sand include calcium carbonate (CaCO3) and aragonite (CaCO₃).
How Does Sand Put Out Fires?
Sand works to put out a fire by starving it of oxygen. Fire is an exothermic reaction (energy is released in the form of heat or light) that relies on fuel and an oxidiser, which is usually in the form of atmospheric oxygen. Once the oxidiser is cut off the fire goes out.
However, if you use sand to put out a fire, it will leave particles of sand leftover onto whatever object or area was burning. This will require additional cleanup. Sand particles are also bad to a person’s health when inhaled, so it must be removed.
Is Sand Flammable?
No, sand is not flammable or combustible.
The reason is the silicon dioxide that makes up sand is formed from burning silicon with oxygen, which removes any unoxidised silicon. The oxygen and silicon form strong bonds that are not susceptible to ignition. However, sand can be melted at extremely high temperatures, but this is unlikely to happen in any ordinary situation, even when poured onto a fire.
Sand Fire Extinguishers – Do They Exist?
No, sand fire exinguishers do not exist because propelling the sand out of the container would be too difficult. Sand is also heavy so the container would weigh a lot more making them harder to carry.
Is Sand Used In Fire Extinguishers?
Fire extinguishers do not contain sand as one of their fire-fighting agents. Today’s fire extinguishers have many ingredients that are very effective at supporessing fires, so sand is not needed.
Do Firefighters Use Sand?
Firefighters use what is most effective to put out fires. Most often this is fire hoses filled with water or foam. Even grease fires, which sand is effective at putting out, will be extinguished by firemen using large amounts of water sprayed on to it. This is done under high pressure and from a safe distance. And even though water is generally not good for putting out grease fires, the amount sprayed will subdue any flashes or flareups.
Fire departments are most often the first responders that arrive during chemical spills, such as petroleum. Sand, among other materials, is used by fire departments to control and contain these. Sand is also used to by fire departments to absorb dangerous waste material left on roadways, such those produced from automobile accidents.
Best Type Of Sand For Putting Out Fires
There are different types of sand, both man-made and found in nature. So which one is best for putting out fires? This does not have a clear answer, because most people do not have access to multiple types of sand when a fire breaks out.
Some types of sand include:
- Pit Sand
- River Sand
- Mason’s Sand
- Beach Sand
- Artificial Sand – made of crushed stone
- Desert Sand
- Volcanic Sand
- White Sand – Calcium carbonate
- Green sands – Glauconites
Organic sands, or those found in nature such as desert and beach sand may have impurities that can lend themselves to combustion.
So, the best sand would be that which is less likely to ignite due to its molecular structure. Sand made of predominantly silicon dioxide will not combust. Also, sand with smaller grain particles rather than large ones is more effective at smothering a fire.
Pouring Sand On A Fire
Is pouring sand on a fire the best way to put a fire out?
This depends. Pouring sand on fires is an ancient method for putting them out. Today, we have fire extinguishers specially designed to put out fires quickly. So, even though pouring sand on fire works, it may not be the best method.
A bucket full of sand is effective at smothering a fire, but comes with some limitations. These include:
- Not having enough sand available.
- Not putting out the fire completely and letting it smolder underneath to reignite later.
- The fire is too large for the sand to be effective.
- The fire is petroleum based and will not extinguish.
- Getting too close to the fire while attempting to pour the sand leading to burns.
However, sand is still effective at putting out small fires. So, having a bucket of sand in your garage, workshop, or campsite when needed is a good way to keep fires from getting out of control.
What Fires Cannot Be Put Out With Sand?
Sand may not be able to put out all types of fires.
Some fire cannot be put out with sand due to their ability to burn underneath the top layer. These types of fire include petroleum fires or large wood fires.
Other types of fires that cannot be put out with sand include:
- Natural gas that burns through the sand as it rises from the ground.
- Burning oil from a well or large spill (on land or at sea).
- Fires in space (zero-gravity)
- Fires above the floor level (wallpaper, ceiling, counter tops, etc.).
- Metal fires (Class D)
- Electrical fires (Class C)
- Rag or clothing fires soaked in oil or gasoline.
The biggest issues with using sand to put out a fire is not having enough, leaving embers to smolder undereath which ignite later, and the sand sinking to the bottom while the fire remains on top.
When using sand to put out a fire, always follow it up with a fire extinguisher or large quantities of water to make sure no embers are left buried deep down that could pose a fire risk.
Why Do We Use Sand To Extinguish Fire?
Sand does a good job of smothering fire and preventing it from getting oxygen. It’s a fire extinguisher that you do not need to recharge, its inexpensive, and it is generally available in most places. Throwing sand on a fire also does not require much skill or training.
Why Don’t Firefighters Use Sand Instead Of Water?
With sand being so good at putting out fires, one might ask why firefighters do not use it instead of water. It has been discovered by firefighting professionals and fire extinguisher companies that sand is not a very good firefighting agent.
Water is more available than sand, and can run through large fire hoses that propel mass quantities of it at safe distances. Large amounts of water is good for knocking down large fires, flare ups, and soaking embers quickly. It is also non-toxic and will not leave residue that can be inhaled.
Sand For Fire Pit
Sand is so good at preventing fire, it is often used to make fire pits. It is fireproof and will not help a fire spread. Sand is also easy to dig and shape to make a circular contained area.
Sand Around Fire Pit
Sand can be used to encircle a fire pit and build up the sides. The sand around fire pit is used to collect embers that may shoot out of the fire pit. It also keeps the fire contained in the fire pit, allowing for fire pits with screens or grates to be used safely.
Why Put Sand In The Bottom Of A Fire Pit?
The bottom of a fire pit will get extremely hot, and nothing burnable will survive. Covering it with sand will allow you to make sure no tree roots in the ground ignite when you have finished with your campsite.
Sand is also good at absorbing heat, and this is distributed throughout the entire base of the fire pit. If your backyard fire pit has a metal liner in its base, sand will help prevent it from deteriorating over time. One or two inches of sand is usually enough.
However, if you like to use fire pit ash as soil fertilizer, this will be more difficult if it is mixed with the sand. Sand also retains moisture, which could cause corrosion to the metal or brick layer underneath.
Why Does Sand Not Catch On Fire?
Sand does not catch on fire because it is fireproof, as discussed earlier in this article.
Can Fire Burn On Sand?
If fire burns on sand, will it ignite? Is this safe?
Fire may burn on sand, but it is suitable fire safety practice to extinguish fire on sand. If fire burns on sand, it can still spread quickly and become difficult to extinguish. Sand by itself is not a fire extinguishing agent: fire will stay active as long as there is fuel and oxygen available.
Bucket of Sand to Put Out a Fire
Is a bucket of sand enough to put out a fire? Yes, as long as it is small. Keeping a bucket of sand stored nearby in a workshop or garage can come in handy when you need it. In fact, buckets of sand are a traditional way of putting out fires, along with buckets of water.
What Type Of Fire Is Sand Used For?
Sand is best for putting out small fires, such as a fire in a barbecue grill, campfires, or those on the floor of a garage or workshop.
Sand may also be successful at putting out fire that is burning within an engine compartment or other confined space.
Regardless, fire can easily spread out of control. So, using a proper fire extinguisher or calling the fire department may be the best choice after you exit the building.
Can Sand Be Used On Class D Fires?
Class D fires are some of the most dangerous fires faced by fire fighters. A fire involving combustible metals can be incredibly hot and almost impossible to put out. If a metal fire is small enough, a bucket of sand may be able to completely smother it. However, the fire can easily flare up again. That is why it is recommended to use a proper Class D fire extinguisher for these types of fires.
Can Sand Be Used To Stop Electrical Fire?
Like metal fires, electrical fires can be difficult to extinguish. One major issue is that electrical fires often do not start at floor level. They can be from wall outlets, broken plugs, lighting fixtures, appliances in upstairs bedrooms, or workshop ceiling and wall wiring. In these cases, sand is not practical as an extinguisher.
Pouring sand on a burning appliance will also not work very well, even when it is sitting on the floor. The sand will simply fall through small openings and out on to the floor.
Electrical fires should be put out using an ABC fire extinguisher. It is also good to cut the power to the house or building so the fire cannot reignite from the same source.
Will Sand Put Out A Grease Fire?
Grease fires are some of the most common sources of home fires. Sand can put out grease fires, but not the way you might think.
Grease fires usually start when something hot like cooking oil is left unattended on the stove causing it to ignite. This fire spreads quickly and can reach up to 575 degrees Fahrenheit according to fire experts. The biggest mistake people make in this situation is pouring water onto it. This will only make the grease fire worse as it can cause busts of flame to spread throughout the kitchen.
Is Sand Better Than Water To Put Out Fire?
The answer to this is not so straightforward. If the fire is on solid material, sand would be better than water. On the other hand, if the fire is on liquid fuel such as diesel or gasoline fire, fire extinguisher with water should be used instead of sand. Water is also better for wood fires where it will soak through any remaining embers so they cannot reignite.
Sand Vs Fire Extinguisher Cost
A 50 lb. bag of sand will cost between $5-10 USD. A fire extinguisher will cost between $30 – 100+ USD. So, sand is much cheaper to buy than a standard fire extinguisher.
Sand can be found at local home improvement stores or anywhere sand products are sold. Whereas, specialized fire extinguishers may be harder to find.
Which is Better: Fire Extinguishers Or Sand?
Both fire extinguishers and sand can put out fires. Overall, when used properly, fire extinguishers are more effective than sand. However, fire extinguisher users must be trained in their proper use.
Fire extinguishers have been specifically designed to fight fires, while sand is regarded as a general purpose building material. Although sand is much cheaper than fire extinguishers, it is not a specialized fire suppressant.
Fire extinguishers contain fire retardants that are made specifically to fight flames by cutting off oxygen and absorbing heat. Sand is really only good at smothering fires and is limited to certain sizes and types of fires.
When considering your home or building safety, betting that sand will help save you in the case of a fire may not be wise. Instead, having proper fire extinguishers and planned escape routes is the safest way to go.
When a fire breaks out, having the right fire suppressant available can mean the difference between staying safe or being caught in severe danger. Fire can be very dangerous when it gets out of control. Regardless of which fire suppressant you use, make sure to keep your safety and those around you in mind and always follow recommended fire safety procedures.
Nick Klamecki is a certified Fire and Workplace Safety expert with 15 years experience in product research and testing. He has a degree in Economics from U.C. Davis, is an active outdoorsman and spent years ensuring the safety of special needs children. Nick researches and tests workplace, industrial and safety products and provides advice on their safe use.