Will Antifreeze Kill Grass?

Antifreeze is used in vehicles to prevent overheating, especially in extreme weather. Sometimes antifreeze accidentally spills from engines and containers onto the lawn. Antifreeze spills can adversely affect grass depending on the type and the concentration of antifreeze.

The antifreeze spills on grass will stunt its growth. The alcohol-based chemicals will stunt the growth of the grass and or even kill it. The most severe effects will be from ethylene glycol-based antifreeze, but you can immediately neutralize the spill to salvage the grass and surrounding area. 

What happens if antifreeze gets on the grass?

There are two forms of antifreeze, and both are toxic to grass. However, ethylene glycol-based antifreeze will kill grass and any vegetation it touches. The deterioration starts days after the ethylene glycol antifreeze gets on the grass. In large doses, it will seep into the soil and contaminate water sources and decimate root systems. The Propylene glycol-based antifreeze is a less-lethal and milder on grass only in its diluted form. 

Uses of antifreeze?

Antifreeze is used to prevent overheating or freezing in car radiators and other automobiles. It’s also used in heating, conditioning, and ventilation systems to keep the pipes from freezing. It’s most common in winter since it clears ice on driveways.

Although antifreeze is an essential part of machines, it is toxic to plants such as turfgrass.

It contains glycol as either ethylene glycol or propylene glycol as the main ingredient. Antifreeze also contains other chemicals such as additives, dyes, and corrosion inhibitors. 

Ethylene glycol is toxic and hazardous to grass, while propylene glycol is not as harmful unless concentrated. Ethylene glycol eventually breaks down into non-toxic substances, carbon dioxide, and water.

Used antifreeze is still toxic because it contains additional chemicals. Lead and Benzene are products found in used antifreeze that are potentially harmful to turfgrass.

The extent to which antifreeze kills grass depends on the ingredients, the type, and the concentration of glycol. 

Impact of antifreeze on the grass?

While it’s toxic to grass, ethylene glycol is not persistent in the soil. It eventually breaks down. However, it will cause the following adverse effects on the grass in high concentrations.

  • The lawn will be patchy and discolored in the spill area.
  • Antifreeze inhibits turfgrass growth. In most cases, there will be an 80% reduced growth of grass. Reduced growth is caused by the low absorption of water by the roots. Ethylene glycol-based antifreeze stresses the roots, delaying or completely stopping their development.
  • The height of the grass reduces by around 30% per week. The antifreeze eventually kills the grass. 
  • Because Antifreeze affects all plants, it will inhibit the growth of weeds, shrubs, and trees on the lawn.
  • Ethylene and propylene glycol antifreeze cause adverse effects on beneficial microbes in the soil.
  • Antifreeze spills and disposal on the lawn can create runoff of the toxic chemicals to water streams and groundwater. 
  • Ethylene glycol and propylene glycol chemicals on the lawn are toxic to pets and humans and cause immune-response diseases.

Turf injury from antifreeze differs according to the concentration and extent of the spill.

Controlling Antifreeze on the lawn

Antifreeze has instructions on the label on how to contain and neutralize spills. Read the instructions and follow them if they are applicable on your lawn. 

  • Clean and neutralize the spill immediately. If you have antifreeze in your home, it is good to have sand, ash, cat litter, or sawdust somewhere in the compound specifically to handle antifreeze spills. 
  • Pour a generous amount of these substances on the spill and the surrounding area to prevent spreading. Wait for about 30 minutes before clearing the area. 

Place absorbent material such as rugs, pads, and old clothing on antifreeze spills. Allow the absorbent material to soak up the remaining liquid from the ground then dispose of it in trash bags. Do not hose the spill with water before first neutralizing it.

  • Avoid dousing the spill area with water. The antifreeze chemicals are harmful to underground water sources.

Observe these other tips to control antifreeze on the lawn. 

  • Because propylene glycol antifreeze is significantly non-toxic to grass compared to ethylene glycol, you should consider using it as an antifreeze in your vehicles. 
  • Drain antifreeze immediately from the radiator and heater core to prevent spills.
  • Recycle the antifreeze waste. Locate your local recycling center to direct you on how to dispose of used antifreeze. Ensure the disposal or reprocessing complies with government or local disposal regulations.
  • If you don’t recycle the antifreeze waste, you should treat it as a dangerous substance. 

Will Diluted Antifreeze Kill Grass?

Pure antifreeze does not contain water. If you add water to the antifreeze, it creates a coolant. Diluted antifreeze will still kill grass if it contains ethylene glycol. Ethylene glycol, even when diluted, is still toxic. It is not biodegradable and will cause problems to the grass. 

Ethylene glycol is toxic and will slowly kill the grass by first reducing its growth. 

Propylene glycol antifreeze isn’t as harmful as ethylene glycol. While it is not considered toxic or dangerous to grass or other plants, it can cause yellowing. Additionally, the contaminants such as copper, lead, zinc, and 1-4 dioxane found in antifreeze will prevent the grass from thriving.

How do you neutralize antifreeze on a lawn?

Antifreeze spills will kill the turfgrass if not cleaned and contained immediately. You’ll need to immediately neutralize the spill to salvage the grass and surrounding area.

  • The first step is to use an absorbent material like sand, clay, or cat litter to control the spill. Use baking soda for smaller spills. 
  • Layer towels, newspaper, and sponges on the absorbent material to contain it. The absorbent materials prevent the antifreeze from spreading further. Continue adding until all the liquid is absorbed.
  • Allow the material to absorb the antifreeze and wait for approximately 1-3 hours for the absorption.
  • Pick up the absorbent material and dispose of it together with the towels into the trash. Use a heavy-duty plastic bag to dispose of everything contaminated.
  • Wait for the dried antifreeze to break down before you hose down the remaining material with water. Let the affected spot air dry and check if there are any stains on the grass.
  •  If any stains remain, repeat the process as many times as necessary to ensure all the antifreeze is decontaminated and neutralized.

Tips for handling antifreeze spills on grass

  • Wear protective gear like gloves and a nose mask to prevent inhalation and skin contact. 
  • Keep children and pets away from the area. 
  • Clean all the equipment used thoroughly.
  • Antifreeze is dangerous if ingested by people or animals. Pets have reportedly died from antifreeze poisoning. 
  • Keep your antifreeze in a labeled container and away from children.

How long does antifreeze stay in the ground?

Ethylene glycol and propylene glycol are biodegradable and will be broken down into carbon dioxide and water. The breakdown takes several weeks or months in the ground, depending on soil temperature. 

The biodegradation rate is higher in soils with more organic matter and higher temperatures. In the air, it takes 10 days to dissipate entirely. 

When glycol is broken down in the soil, the acidic byproducts lower soil pH.

Ethylene glycol or ethanol-based antifreeze will take longer to break down in the soil than propylene glycol.

In conclusion, avoid pouring or disposing of antifreeze into the environment because of the dangers imposed on humans, plants, and water bodies. 


  1. Center for Disease Control(CDC): Toxicological profile for Ethylene Glycol.

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