How do you Stop your Mask from Fogging Up?

When you’re snorkelling, nothing is more annoying than having to always de-fog your facemask. How do you stop this happening?

From regular toothpaste to good old fashioned spit, we’ll run through how to prepare your new mask and what you can use to have a fog free snorkel.

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Snorkel Mask

Treating a New Mask

The first thing you need to do to stop your mask fogging up is give it a good clean when you take it out of the box.

If you have bought a tempered glass facemask, there will still be residue on the glass from the manufacturing process. You need to remove this residue otherwise you will have a very foggy time of it.

Use toothpaste to clean your new mask

Believe it or not, the most effective way to clean a new mask is to smear a dab of standard white toothpaste (not whitening, gel or mint) over the inside glass. You can do the outside glass too if you want to be thorough.

Leave the toothpaste there for a couple of hours to dry, then rinse it off with water.

To check you have got all the residue off, breathe onto the inside of facemask. If you notice any areas stay fogged up, you might need to repeat the process.

Avoid mint toothpaste. The residue of this can affect your eyes when you wear the mask.

Don’t use gel or whitening toothpaste, they either don’t have the right ingredients or could scratch the glass.

Standard white toothpaste is all you need. We use a soft toothbrush to get it right into the corners of the glass.

Using a lighter – not recommended

You can also burn off the residue in the mask using a stove or cigarette lighter. By holding the flame up to the glass of your mask, you will see a halo as the residue burns off. It might leave a black soot on the glass which you just rinse off.

Why we would never use a lighter

There are a couple of reasons I stay away from using a lighter. First, you can damage the glass if you leave the flame too close to it for too long.

The next issue is that if the flame gets too close to the edge of the mask, you could damage the silicone seal.

We can’t see how you clean the whole glass surface without getting close to the silicone so scrubbing toothpaste in with a toothbrush or your finger is a much better option.

Best Ways to Stop your Mask Fogging Up

While there are different ways to de-fog your mask, they all work the same way. Something that prevents fog forming is called a surfactant. They are both naturally occurring and commercially produced and all make it harder for water vapour to form fog.

With your new facemask prepared for use, it might still fog up if water gets inside or you exhale through your nose. There are several ways to stop your mask fogging while you snorkel.


You won’t find a more naturally occurring surfactant than our own saliva. Dribbling a bit of saliva or spit into your mask, swishing it around and giving your mask a rinse has been a commonly used de-fogging method for years. If it does not gross you out, it is an easy, cheap and effective method.

It has the advantage of always being available to you but, on the downside, a lot of people don’t like doing it and it isn’t a method you would use with someone else’s mask!

However, if you are in the water and your mask is fogging up, using a bit of spit can really rescue your snorkel.

Defog and Mask
Defog & Mask

Baby Shampoo

This is our go to fog control method, and it works brilliantly. Just put a tiny drop of baby shampoo into your mask and work it around with your finger. Give your mask a rinse and you are good to go.

We use a drip of undiluted baby shampoo, but you can also dilute it and keep it in a spray bottle. Anything from a 50:50 to 25:75 shampoo to water mix will get the job done. It is a staple in our bag of snorkelling gear.

We haven’t tried it, but friends use dish washing liquid in the same way.

The only downside to using one of these is making sure you do not apply too much as you don’t want the extra to make its way into your eyes.

Defog Sprays

There are also a number of anti-fog spays that you can buy. Their application is similar to using your own bottle of diluted shampoo.

They involve spraying or adding a couple of drops to the inside of your mask. Some require a quick rinse, others you wait for them dry and away you go.

Like the other two methods, these can be used on glass or plastic masks. They come in handy compact bottles.

Derek Schroeder

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