The short answer
The most important e-liquid terms describe ingredients, proportions, nicotine concentration, bottle format, and intended hardware. PG and VG are carrier liquids. A 50:50 label describes their stated proportion. Mg/ml describes nicotine concentration, not the total nicotine absorbed by a person. Nic salts and freebase describe nicotine formulations. Shortfill and nic shot describe common bottle and mixing formats, not a guaranteed final strength.
Use this dictionary to read a label, then follow the e-liquid selection guide for an actual choice and the e-liquid ingredients guide for the evidence and inhalation-safety boundary. The live e-liquid category owns current products and commercial details.
Key points
- PG, VG, nicotine, flavourings, and other ingredients describe the liquid, while aerosol describes the heated output.
- Mg/ml is a concentration and does not predict the nicotine one person absorbs.
- Nic salt and freebase are formulation terms, not quality rankings.
- Shortfill, nic shot, 50:50, MTL, and sub-ohm describe different parts of the bottle and device decision.
- MHRA publication is a regulatory notification check, not a medicine approval or harmlessness certificate.
Vaping language mixes scientific terms, legal terms, engineering shorthand, and marketing. That creates avoidable mistakes. “Vapour” is commonly used, but the inhaled output is an aerosol. “2%” is often used for 20mg/ml, but neither figure predicts an individual’s absorbed dose. “Food grade” describes a context of use and does not prove repeated inhalation safety.
This glossary gives a practical plain-English meaning, the label detail to check, and the assumption to avoid. It applies to consumer products in the UK as reviewed on 8 August 2026. Exact labels, instructions, and current rules remain controlling.
Common e-liquid terms in plain English
| Comparison point | Plain-English meaning | Check on the exact product | Do not assume |
|---|---|---|---|
| E-liquid or vape liquid | Liquid intended for use in an e-cigarette or vape device | Ingredients, nicotine, volume, warnings, and compatible use | That every liquid suits every device |
| Aerosol | The mixture of droplets, particles, and gases produced when the device heats liquid | Device condition and intended operating range | That it is only harmless water vapour |
| PG | Propylene glycol, a common e-liquid carrier | The declared PG proportion and device guidance | That more PG is automatically better or safer |
| VG | Vegetable glycerine or glycerol, another common carrier | The declared VG proportion and coil compatibility | That high VG works in every small pod |
| 50:50 | A stated balance of PG and VG, normally read as 50 percent of each | The exact bottle label and whether other ingredients affect the full formulation | Identical viscosity or performance across brands |
| Mg/ml | Milligrams of nicotine per millilitre of liquid | The exact concentration and bottle volume | The amount an individual will absorb |
| 1% and 2% | Common label shorthand corresponding to about 10mg/ml and 20mg/ml nicotine | The printed mg/ml value and official label | That percentages describe personal dose |
| Nicotine salt | A nicotine formulation using nicotine with an acid to form a salt | Concentration, ingredients, and compatible setup | That salt is nicotine-free, harmless, or universally smoother |
| Freebase nicotine | A different nicotine formulation commonly used in e-liquids | Concentration and intended device use | That freebase strength can be chosen by a simple conversion from nic salts |
| Nicotine-free or 0mg | A product presented without nicotine | Exact ingredients, volume, warnings, and duty or product rules | That no other inhalation risk exists |
| 10ml refill container | The maximum presentation size for a nicotine refill container supplied to UK consumers under current rules | Seal, nozzle, warnings, nicotine concentration, and notification | That a 10ml bottle is automatically compliant or authentic |
| Shortfill | A common term for a larger nicotine-free bottle left with space for an addition | Bottle volume, fill volume, instructions, ratio, and intended final mixture | A universal bottle size or automatic final nicotine strength |
| Nic shot | A nicotine-containing refill used by some adults to add nicotine to a compatible larger liquid | Strength, volume, mixing instructions, and final total volume | That one shot always creates the same final strength |
| MTL | Mouth to lung, an inhale style that draws aerosol into the mouth before inhaling | Device, coil, airflow, liquid, and power guidance | That the label alone determines nicotine delivery |
| RDL and DTL | Restricted direct lung and direct to lung inhale styles | Airflow, power, coil resistance, liquid, and manufacturer guidance | That every liquid or nicotine strength suits higher-output use |
| Coil resistance | Electrical resistance of the heating coil, stated in ohms | Exact compatible coil and operating range | That resistance alone predicts power, vapour, flavour, or safety |
| Ice or cooling | A flavour-name cue that signals an intended cooling direction | Manufacturer description and exact ingredients where available | A measured temperature or universal cooling intensity |
| MHRA notified product | A relevant nicotine product whose notification has been published on the official list | Exact brand, product, flavour, strength, submitter, and identifier | Medicine approval, authenticity of every unit, or harmlessness |
| Puff count | A manufacturer result or estimate under particular conditions | Test method, mode, liquid volume, and up-to wording | A guaranteed number of personal draws or days |
| Best before and batch code | Traceability and product-condition information on the physical pack | Legibility, seal, storage instructions, and manufacturer route | That an in-date bottle is automatically authentic or uncontaminated |
Important context: Definitions are intentionally narrow. Use the exact physical label, manufacturer instructions, and current official guidance for the selected product.
Read an e-liquid label in five passes
Identify the exact product
Match brand, range, flavour, strength, volume, responsible person, and batch information.
Read nicotine in mg/ml
Treat it as liquid concentration, not as a prediction of absorbed dose or a flavour feature.
Check formulation and format
Note PG/VG information, nic salt or freebase wording, bottle size, and any mixing instructions.
Match the hardware
Confirm the device, pod, coil, resistance, airflow, and operating guidance support the liquid.
Check warnings and traceability
Inspect seal, label, batch, best-before information, storage instructions, and applicable MHRA record.
Use the glossary according to the task
If you are comparing two bottles
Match format, concentration, volume, ratio, and intended hardware first
Those are reproducible product facts.
Watch for: They do not establish taste or personal nicotine delivery.
If you are considering a shortfill and nic shot
Follow the exact manufacturer mixing instructions and calculate the final total volume
Bottle and shot sizes vary.
Watch for: Seek advice rather than guessing nicotine needs.
If you are checking legal supply
Match the exact product to the applicable MHRA published record and physical label
Generic brand matches are insufficient.
Watch for: Notification is not medicine approval or proof of every unit.
Labels do not replace compatibility, storage, or health advice
Use e-liquid only in equipment whose manufacturer instructions support it. Keep nicotine products away from children and pets, close bottles securely, follow storage directions, clean spills correctly, and never swallow or improvise ingredients. Do not refill a sealed component that was not designed for consumer refilling.
Adults using vaping to stop smoking can seek NHS or local stop smoking support. Non-smokers, children, and young people should not vape. Concerning symptoms need healthcare appropriate to severity. Suspected side effects and product defects can be reported through MHRA Yellow Card.
E-liquid terminology questions
Is vape liquid the same as vape juice?
They are commonly used for the same product category. The exact label and intended device use are more important than the informal name.
Does 20mg mean 20mg in the whole bottle?
On a UK e-liquid label it normally means 20mg of nicotine per millilitre. Check the printed mg/ml concentration and total bottle volume separately.
Is 50:50 suitable for every pod?
No. It is a formulation statement, not a compatibility guarantee. Follow the exact device and coil instructions.
Does food grade mean safe to inhale?
No. Suitability for food use does not establish safety for repeated inhalation or after heating.
Does MHRA notification mean approved?
It is a required publication check for relevant nicotine products, not a medicine licence, authenticity guarantee, or harmlessness certificate.
Live products, prices and stock
This article explains the question or review. Use the linked shop pages for current product options, prices and availability.
Related reading
Sources and verification
- E-cigarettes: regulations for consumer productsMedicines and Healthcare products Regulatory AgencyChecked: 8 August 2026
Supports: UK definitions and requirements for nicotine-containing e-cigarettes and refill containers, including concentration, volume, notification, ingredients, packaging, and reporting.
- Chapter 6: advice on ingredients in nicotine-containing liquidsMedicines and Healthcare products Regulatory AgencyPublished or updated: 16 August 2024Checked: 8 August 2026
Supports: Ingredient terminology, toxicological responsibilities, prohibited substances, emissions, and the limit of food-use status.
- Using e-cigarettes to stop smokingNHSChecked: 8 August 2026
Supports: Plain-language explanation of e-cigarettes, aerosol, typical e-liquid ingredients, nicotine, adult cessation context, and risk boundary.
- Nicotine vaping in England: 2022 evidence update summaryOffice for Health Improvement and DisparitiesPublished or updated: 29 September 2022Checked: 8 August 2026
Supports: Evidence on devices, formulations, flavours, emissions, nicotine delivery, exposure, and uncertainty.
- Introduction of Vaping Products Duty from 1 October 2026HM Revenue and CustomsPublished or updated: 26 November 2025Checked: 8 August 2026
Supports: Definition and scope of vaping liquid for the duty beginning 1 October 2026, including nicotine and non-nicotine liquid.
Editorial record
- Last reviewed
- 8 August 2026
- Next review due
- 8 December 2026
What changed
Rebuilt the legacy dictionary into a concise UK glossary covering ingredients, ratios, nicotine notation, bottle formats, device terms, notification, puff claims, storage, and explicit limits on what labels prove.
Disclosure
Vape Forest sells e-liquids and devices linked from this glossary. Definitions use official health and regulatory material. Product links are contextual, and no competitor retailer source or promotional ranking determines the content.
