WHAT IS A SHORTFILL E-LIQUID?

WHAT IS A SHORTFILL E-LIQUID?

A ‘shortfill’ e-liquid is a mixture of propylene glycol, vegetable glycerine and flavourings just like normal e-liquid, except that shortfills do not contain nicotine. This allows the user to add nicotine to the shortfill e-liquid, creating an e-liquid tailored to the specific nicotine strength and type of nicotine desired by the user. This circumvents the legal maximum strength for retail e-liquids.

INTRODUCTION

*2022 Update - If you prefer the ease of pre-filled E-Cigarettes, check out the new SMOKO VAPE POD! It's small, discreet and uses our great-tasting UK-made liquids! 

What is a 'shortfill'?The variation of products available can make the vaping marketplace a little intimidating, from devices that look like a cigarette, to these box-looking units that people fill with their own e-liquid, or ‘vape juice’.

The vape market in the UK protects its customers by adhering to the Tobacco and Related Products Regulation (TRPR), which enforces everything from warnings on labels to the ingredients allowed in e-liquids. (1)

One of the regulations dictates the maximum nicotine strength allowed in products sold off the shelf, and this is a 2.0% mixture, or 20mg of nicotine per ml. Shortfill e-liquids allow consumers to mix their own liquids, and can therefore circumvent these regulations. Cunning, hey?

Mixing your own e-liquids requires using a device with a refillable tank. This gives the user more control with regard to flavours, nicotine strength, and the balance of vegetable glycerine to propylene glycol (VG PG), but there is such a thing as too much choice! 

Customers at SMOKO are looking for a simple device that is easy and simple to use, in a tobacco flavour to achieve a sensation close to smoking - do shortfills help to achieve this? Or do they make things a lot more complicated?

WHAT IS SHORTFILL E-LIQUID?

So, what is a shortfill? A shortfill e-liquid is an e-liquid without the nicotine. That means the flavouring, vegetable glycerine and propylene glycol are all there, ready to go - you just need to add nicotine. 

The key to shortfills is not just that they contain nicotine free e liquid - the name comes from the fact vape juice takes up most of the bottle, but not all of it. A little extra space is left in the bottle - it is ‘short filled’ so that an amount of nicotine can be added and mixed in the bottle. 

HOW DOES SHORTFILL E-LIQUID WORK?

When you buy a shortfill e-liquid, it typically comes in a 60ml or 120ml container, with only 50ml and 100ml of nicotine inside - leaving a 10ml or 20ml space for the nicotine to be added. 

The 50ml shortfills come in a 60ml bottle, so users will add 10ml nic shots to fill the bottle to the top, and then shake vigorously to thoroughly mix the nicotine in with the e-liquid. In the larger 100ml shortfills, the bottle is 120ml, which will leave space for 20ml of nicotine shots to be added.

And if that wasn’t complicated enough…

HOW DO YOU DETERMINE THE NICOTINE CONTENT THAT CAN BE ADDED?

In the UK, the strength of retail liquids range from 0% up to 2%, or 20mg/ml. For many heavy smokers this is fine, but there are people out there who increase the nicotine level beyond 2% when they mix their own e-liquids. 

No, don’t dig out the chemistry set just yet! Better grab a calculator though…

To use the shortfill as designed, you are limited to the volume of the extra space left - so in a 60ml bottle this will be 10ml. The strength of the final product will be determined by the strength of the nic shot added.

The most common strength nic shot appears to be 18mg strength, this allows for relatively easy mixing of 0.3%, 0.6%, 1.2% and 1.8% nicotine liquids. Adding a 10ml bottle of 18mg nicotine to a 50ml shortfill will give you a final product of 60ml of 3mg/0.3% e-liquid.

Stronger nic shots are available though, if you need a stronger liquid! The stronger forms of nicotine shots use a type of nicotine known as ‘nic salts’ as opposed to the traditional freebase nicotine, because it produces a smoother inhale. (2)

This form of nicotine produces a smoother inhale, which is important for super high strength liquids (above the 2% legal retail limit) as nicotine contributes to the throat hit. Using nic salt nicotine shots here should keep you from suffering coughing fits every time you vape!

*2024 Update - Studies on nic salt have found that the reason why nic salts produce a smoother inhale is due to the fact it isn't absorbed by the throat, like freebase nicotine is. This means that more nicotine reaches the lungs, however nic salts are charged particles, and so have a hard time crossing the barrier of the lungs into the blood (3). Nic salt particles are also larger than freebase nicotine particles, which means that nic salt is likely to produce a larger inflammatory response than freebase nicotine. (4) 

As you can see, this method of vaping is going to take a lot more of your time and effort, it requires more ingredients which means more storage space needed for all your vaping kit.

I bet the SMOKO E-cigarette is looking like a good choice right about now!

CAN YOU USE SHORTFILL E-LIQUID WITHOUT NICOTINE?

That shortfill bottles are ready mixed vape juice, just without the nicotine, means you can use shortfills without adding the nicotine in. Why would you do this? For the flavour! 

Additionally, even most 0mg nicotine liquids come in 10ml bottles, so grabbing the larger bottles will give you 50ml in each single container, which may reduce the number of e-liquid bottles you need to carry around!

CAN SHORTFILLS BE USED FOR ANY VAPE KIT?

Mixing your own bottles of e liquid should allow you to tailor your liquid for your device. The important part here is the balance of VG to PG that the shortfill is composed of. Vegetable glycerine is thicker than propylene glycol, so the high VG liquid range needs to be used in a more powerful device.

It is worth knowing that the vaping process uses the PG faster than VG (5), which results in a higher VG ratio the more you vape, so choosing a liquid that is skewed toward PG should keep the flavour and throat hit for longer. 

Even assuming you mix the right balance of liquid, your homemade mixture is not designed for use in any device that uses pre-filled cartridges, like the SMOKO E-cigarette. These refills are sealed units, tested and guaranteed to work with the liquid contained therein; opening them up to put in your own liquid will void any manufacturer’s guarantee, and likely deliver a sub-standard vaping experience.

WHAT ARE THE BENEFITS OF SHORTFILL E-LIQUIDS?

The advantage of using shortfill e-liquids is that you can control the nicotine content of your preferred flavour of liquid. For the experimenters among you, you can mix flavours without having to worry about nicotine levels; the only nicotine going into the liquid is that which you decide to add!

There are plenty of drawbacks to using shortfills - you need to have the constituent parts to mix, so if you forget to pick up either your nic shots or shortfill you don’t have everything you need to carry on vaping! Then there’s the time spent mixing, potential spills leading to wasted liquid, and cleaning that may be necessary. 

There are a lot of manufacturers with offerings in this corner of the market, where the e-liquid in SMOKO’s e-cigarette refills are made here in the UK, shorfills are available from all over the world, so not all of them will be subject to a good degree of regulation, and could contain harmful ingredients. You may save a few pennies going with cheap liquids, but is it really worth the risk to your health?

ARE SHORTFILLS THE RIGHT CHOICE FOR YOU?

The control that shortfill e-liquids give to the vaper is to be lauded; it gives the consumer all the power to make a bespoke product for themselves. As great as that is, for many consumers looking to quit tobacco, a simple and stress-free tobacco flavoured option is preferable to this degree of effort and choice. 

To use shortfill e-liquids, you are going to need a device with sufficient power, which translates to a more complex vape device with replaceable parts - so using your own shortfill mixed liquids not only means time spent making the liquids, but also time spent maintaining your device.

There is potential to get your mix wrong, which may incur some effort to save the liquid, or might see it all go to waste if you aren’t willing to compromise your vaping experience! 

You need to make sure you are paying attention when purchasing, too - because of the huge variety in the strength and composition of nic shots, there is more potential to order the wrong one! This could lead to a different VG PG balance than you normally use, and a different nicotine level. 

The last thing to keep in mind when mixing your own liquids is that there is some evidence that more flavourings results in a stronger inflammatory response in cells exposed to vape aerosol, suggesting that mixing flavours increases the risks from vaping. (6)

WHAT IS A SHORTFILL E-LIQUID - CONCLUSION

Hopefully we have answered the question of 'what is a shortfill' and how you use them! Being able to mix e-liquids to taste is advantageous if you are chasing the perfect nicotine level, the perfect flavour, or the perfect inhale experience. 

However, the bottom line is that as you increase the number of variables, so, too, do you increase the number of things that can go wrong. For the more meticulous vapers with lots of time on their hands, this may not be a problem, but many smokers are looking for a simple, easy vaping experience to help them quit smoking, and do it cost effectively. 

If this sounds like you, then check out SMOKO’s E-cigarette starter kit deals for a look at some simple, no mess vaping options, where all you need to worry about is having a battery and refills!

*2022 Update - Now you can get a FREE E-Cigarette Starter Kit when you buy a box of SMOKO E-Cigarette refills! (One per customer)

REFERENCES

(1) E-cigarettes: regulations for consumer products

(2) Comprehensive Dutch market data analysis shows that e-liquids with nicotine salts have both higher nicotine and flavour concentrations than those with free-base nicotine

(3) Pod-mod vs. conventional e-cigarettes: nicotine chemistry, pH, and health effects

(4) In vitro toxicological evaluation of aerosols generated by a 4th generation vaping device using nicotine salts in an air-liquid interface system

(5) Impact of e-Liquid Composition, Coil Temperature, and Puff Topography on the Aerosol Chemistry of Electronic Cigarettes

(6) Inflammatory and Oxidative Responses Induced by Exposure to Commonly Used e-Cigarette Flavoring Chemicals and Flavored e-Liquids without Nicotine

ABOUT THE AUTHOR

Written by Dan Overgage

Dan Overgage is a former smoker of 10 years until he became a client of SMOKO E-Cigarettes.  Dan started working with SMOKO 5 years ago after successfully quitting using our e-cigarettes and works across our Customer Service and heads up our content creation and research with a strong focus on all things quitting smoking.  During his tenure with SMOKO, Dan has written countless blogs and consults with countless clients every day to help them to stay smoke-free.