What happens when you leave e-liquid in the heat

It’s a summer morning and you’re driving to work, as usual. You head into work for the day – the sun is shining, temperatures are rising, it’s looking good! You finish your shift, go back to your car, and find you’ve left a bottle of e-liquid on the dash in the boiling hot sunlight… all day long.

Sound familiar?

This is something we’ve probably all done from time to time. Then, we’re left wondering if we can still vape the e-liquid or whether it’s been cooked to destruction. And of course, you’ve taken to the internet to find your answer!

The short answer is: throw the e-liquid away. It’s too late, sorry.

Leaving e-liquid in a hot place, whether it’s in the car on a warm day or on the windowsill in direct sunlight, is not a good idea. Exposure to heat and light essentially means the taste, texture, and strength of the e-liquid will all be affected.

Heat and sunlight exposure speeds up the ageing process of the molecules inside VG and PG – the two main components of all e-liquids. This means the molecules break down rapidly and cannot recombine, even when returned to cooler temperatures. This is known as oxidation.

The result of this is a very thin e-liquid with a pretty bland flavour. The e-liquid could leak from your device when it becomes this thin, plus, the nicotine strength will be affected. So, even if you aren’t worried about the spoiled flavour, we still wouldn’t recommend using it. 

These effects are even more apparent in nic salt e-liquids as the breakdown happens even quicker.

The good news is that your e-liquid will not be dangerous to use. Nothing in the juice can turn toxic just by heating up slightly, but it still won’t be very pleasant to use. 

The best thing to do is throw the e-liquid away and, if it’s your whole e-cigarette that’s been left in the heat, change the coil too. 

For future reference, it’s best to store e-liquids in a cool, dark place. More specifically, you should aim for temperatures between 10-20 degrees celsius – so you don’t want it to be too cold either.

In summary, storing your e-liquid in a hot car, direct sunlight, or in the fridge is a definite no-go, and you should probably just throw it away.