Will a Fire Extinguisher Kill Grass?

Lawns are often prized by their owners for their attractiveness and value they add to a home. However, some substances can harm a lawn, even kill it. Will a fire extinguisher kill grass? Find out below.

Do Fire Extinguishers Kill Grass?

Fire extinguishers that contain ammonium sulphate or sodium bicarbonate (or other salts) can kill grass. This substances are usually found in class B and C dry chemical fire extinguishers.

Fire extinguisher powder can also smother the grass, preventing it from getting enough sunlight. This is similar to leaving a tarp or camping tent on a lawn too long. Eventually, the grass underneath will die because it has been blocked from the sun’s rays.

Chemicals That Are Toxic To Grass

Grass can be killed or harmed by certain chemicals and substances, including:

  • Herbicide (glyphosate)
  • Dish detergent
  • White vinegar
  • Baking soda
  • Salt

Each of these work to kill and removin unwanted grass and weeds from a yard. But if you accidentally get them on your lawn it will kill or damage it fairly quickly.

If you want to kill grass don’t use a fire extinguisher! Instead use glyphosate herbicide — it will work fast! Here are some good grass killing herbicides to check out:

Killzall Weed and Grass Killer – 41% Glyphosate

Ragan And Massey 75322 Glyphosate Herbicide

Ranger Pro Glyphosate Herbicide Concentrate 2.5 gal

As an Amazon Associate, SelectSafety earns commissions from qualifying purchases made through links in this post.

Why Use a Fire Extinguisher On Grass?

A barbecue or backyard fire pit may get out of control, requiring the use of a fire extinguisher.

Even if you don’t spray directly on the grass, the spray can affect grass and plants nearby. If it is only a slight ammount of spray that gets onto the grass, it probably will not cause much if any harm.

Or, a parent could be showing their kids how to use a fire extinguisher safely, and end up spraying their lawn. However, having your kids know how to use a fire extinguisher can save your home — so forget your grass!

What To Do After Spraying a Lawn With a Fire Extinguisher

Unfortunately, there is no way to completely wash away fire extinguisher powder from a lawn. Some of the particles will seep into the dirt and stay there for an extended period of time. The only thing you can do is to flood the lawn with enough water to dilute the spray and have it wash away from the area as best as possible.

Do not leave fire extinguisher powder on grass without diluting it with water. This is especially important if you have small children and animals that play on the lawn regularly. Kids and animals like to run and roll around on the grass and will pick up the dust particles on their clothes and skin. Check out this article to learn how fire extinguisher spray can be toxic.

Is Spraying a Lawn With a Fire Extinguisher Dangerous?

Spraying a lawn with a fire extinguisher causes minimal health risks to humans and animals.

Spraying any chemical mixture onto a lawn or the ground will end up contaminating ground water to some extent. Fortunately, fire extinguisher chemicals have low toxiticy and are typically harmless to animals and humans in very tiny amounts.

In Closing

It is best to not use a fire extinguisher to try and kill grass or weeds, as there are better and safer options available. However, if a fire breaks out, do not hesitate to use a fire extinguisher. You can worry about your lawn after the fire is gone!

Did you find this useful? If yes please share!
Nick Klamecki, Author
About Nick Klamecki, Author

Nick Klamecki is a certified Fire and Workplace Safety expert with 15 years experience in product research and testing. He has a degree 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. Learn more about Nick here or connect with him on LinkedIn | Medium