Is de-icer bad for your car and the environment?

What is in de-icer

As part of our popular series of  winter car care articles today we focus on de-icers. There are a couple of different variations of de-icer on the market. However, the most common type of de-icer is the aerosol can/spray and the product you're most likely researching. The other type of de-icer for road surfaces is rock salt grit. The vast majority of the chemical composition of a aerosol/spray de-icer is:


A harsh and toxic chemical which helps with the vaporisation of de-icer. It accounts for less than 1% of the composition.

Butane/propane blend

A volatile gas blend commonly associated with lighter fluids which helps with melting the ice. Comprises between 1%-5% of the composition.


Ethanediol helps to depress the freezing point of aqueous mixtures - this is what stops antifreeze itself from freezing and also the materials it comes in contact with (windscreens, windows etc). Highly toxic and accounts for around 5%-10% of the composition. This is essential to make sure the melting solvents don't freeze such as the isopropanol (alcohol). 


Ethanol is a widely used solvent which has a low freezing point and an acidic/corrosive effect which melts ice. It is often used in making alcoholic beverages. Ethanol is the most common ingredient in de-icer and accounts for 10%-30% of antifreeze.  


Isopropanol is highly flammable liquid more commonly known as rubbing alcohol. The alcohol is a key component of the actual antifreeze and accounts for 1%-5% of the composition.


The rest of the composition is water which dilutes the rest of the solvents and makes it sprayable to come out as a liquid once it hits a surface. Without the water being added in de-icer would be even more harmful to humans, animals and the environment than it already is.

What is in rock salt grit

Rock salt is made of halite (posh word for salt) but has additives to make it more full bodied and reduce the concentration.

Is de-icer bad for your car

Modern de-icers do no harm to modern vehicle paintwork. That being said, it is not advisable to put de-icer into any other part of the vehicle including the interior and around the engines especially the engine coolant and motor oil reservoirs as the chemicals do not mix well and could cause irreversible damage.

Rock salt shouldn't come into contact with cars and won't do any damage to the tyres.

Is de-icer bad for the environment

Yes. There are no two ways about it - de-icer is bad for the environment. From the metals used to create the tin, to the methods to get the chemicals all the way to what the chemicals do to any vegetation around where it is applied. The toxic mixture can kill animals who ingest even a little bit of it and it can make any vegetation die and make the soil become infertile.

When using de-icer be extra mindful how much is used and where it is used, alternatively you can use some of the suggestions below.

Rock salt is also harmful to the environment and in particular to animals who may walk on it as it is very acidic, every winter there are several articles and new warnings of the dangers of rock salt to dog's paws, for example. 

What to use instead of de-icer?

Here are environmently friendly alternatives to de icers

  • Covering the windscreen overnight is a good way to prevent frost and ice build-up.
  • Keep your car away from the elements inside of a garage
  • Manual tools such as ice scrapers can help get the stubborn frost off
  • Make a hot water bottle and leave it inside the car to remove the ice from the inside out
  • Using warm (not hot!) water will meet all the ice in an instant. However, be sure not to overdo it and allow it to spill on to the roads as this can form black ice.
  • Regular salt could be a mildly better alternative to grit, however, your local council will use rock salt on public roads so you've got no choice with this one


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