What Is In A Vape
What Is
in a Vape
Four ingredient families. Propylene glycol carries flavour. Vegetable glycerin produces vapour. Food-grade flavourings give each liquid its identity. Nicotine is optional plus capped at 20mg/ml under UK rules. That is the complete list.
Every UK TPD compliant vape e-liquid contains four ingredient families. Propylene glycol (PG) carries flavour plus produces throat hit. Vegetable glycerin (VG) produces vapour cloud. Food-grade flavourings give each liquid its taste. Nicotine at 0mg/ml to 20mg/ml. Every ingredient is disclosed to the MHRA via the UK notification system before the product can be sold. UK vape e-liquid does not contain tar, carbon monoxide, ash or combustion by-products because nothing burns. Schedule 1 of the UK TPD regulations bans specific substances including vitamins, caffeine, colourants and CMR-listed compounds. The ingredient list is deliberately short by design.
Three numbers behind
UK vape e-liquid composition
Ingredient families, nicotine ceiling plus the disclosure requirement.
Ingredient groups
PG, VG, flavourings plus nicotine. The complete ingredient picture for every UK TPD compliant vape e-liquid.
Maximum nicotine
The UK legal ceiling for nicotine strength in any e-liquid. Every ingredient disclosed through MHRA.
Disclosure required
MHRA notification requires full ingredient disclosure on every UK vape SKU before it can legally be sold.
The five things inside every UK TPD vape e-liquid
UK vape e-liquid is one of the most disclosed-ingredient consumer products on the market. Every SKU is registered with the MHRA plus every ingredient is documented by CAS number. Five parts cover the full picture of what goes in a UK vape.
Ingredient 1: propylene glycol (PG)
PG is a clear odourless liquid commonly used across food, medicines plus cosmetics. In vape e-liquid it serves two functions:
- Carries flavour. Most flavour compounds dissolve more readily in PG than in VG.
- Produces throat hit. The slight kick at the back of the throat that mouth-to-lung vapers expect.
- Generally recognised as safe by the US FDA plus approved under UK plus EU food safety rules.
- Also found in asthma inhalers, toothpaste, processed foods plus many medicines.
- Typical UK e-liquid PG content. 50% for nic salts. 30% for shortfills. 20% for cloud-chasing shortfills.
Ingredient 2: vegetable glycerin (VG)
VG is a thicker sweeter liquid derived from plant oils. In vape e-liquid:
- Produces vapour. Higher VG equals more visible cloud.
- Adds mild sweetness. Slightly rounds out the flavour profile.
- Plant-derived. Typically from palm, coconut or soy.
- Also food-grade. Used in countless foods, cosmetics plus medicines.
- Typical UK e-liquid VG content. 50% for nic salts. 70% for shortfills. 80% for cloud-chasing shortfills.
Ingredient 3: flavourings
Food-grade plus cosmetic-grade aroma compounds give each e-liquid its identity:
- Sourced from regulated flavour suppliers. Typically the same companies supplying food plus drinks industries.
- Natural plus nature-identical. Most flavourings mimic fruits, tobacco, menthol, desserts plus drinks.
- Disclosed by CAS number. Every single compound in the flavour mix is listed to the MHRA.
- Banned flavour compounds excluded. Diacetyl plus a small list of others are not permitted in UK e-liquid.
- Typical proportion. 2% to 10% of total liquid volume.
Ingredient 4: nicotine
Optional in every UK e-liquid. Where present:
- Strength range 0mg/ml to 20mg/ml. The UK legal maximum is 20mg/ml.
- Two forms. Freebase nicotine (traditional) or nicotine salt (newer, smoother at high strength).
- Plant origin. Pharmaceutical-grade nicotine extracted from tobacco plants.
- Same nicotine as in NRT patches, gum plus sprays.
- Addictive but not itself the main cause of smoking harm. Combustion is the primary harm driver in smoking.
Ingredient 5: what UK TPD rules ban
Schedule 1 of the Tobacco and Related Products Regulations 2016 prohibits specific substances from UK vape e-liquid:
- Vitamins plus anything suggesting a health or wellness benefit.
- Caffeine, taurine and other stimulants beyond nicotine itself.
- Compounds on the CMR (carcinogenic, mutagenic, reprotoxic) list at exposure-relevant levels.
- Colourants that alter vapour appearance.
- Diacetyl plus a small list of restricted flavour chemicals with inhalation safety concerns.
- Anything that would be illegal outside vape including controlled substances.
Four things UK vape
e-liquid does not contain
No tar
Tar comes from burning plant material. Vape e-liquid is heated not burned so no tar is produced. No sticky lung residue.
No carbon monoxide
CO is the gas that causes much of smoking’s cardiovascular damage. Vaping produces none of it because there is no combustion.
No tobacco leaf
UK vape e-liquid contains no tobacco. The nicotine is pharmaceutical-grade extract. No plant material.
No 7,000+ smoke chemicals
Cigarette smoke contains over 7,000 chemicals plus at least 70 known carcinogens. Vape vapour does not.
UK vape e-liquid ingredients vs
cigarette smoke chemistry
A side-by-side on what the two different products actually put into the user. The contrast is why PHE estimates 95% less harm for vaping.
4 ingredient families
- ✓PG (food-grade). Flavour carrier.
- ✓VG (food-grade). Vapour producer.
- ✓Flavourings (food-grade). Disclosed to MHRA.
- ✓Nicotine 0-20mg/ml. Optional.
- ✓Full disclosure. Every compound listed by CAS number.
- ✓Heated not burned. No combustion by-products.
7,000+ compounds
- ✗Tar. Sticky residue in lungs.
- ✗Carbon monoxide. Cardiovascular toxin.
- ✗Formaldehyde plus acetaldehyde. Aldehydes from combustion.
- ✗Ammonia. Respiratory irritant.
- ✗70+ known carcinogens. Identified in smoke analysis.
- ✗Nicotine (also present). But delivered alongside all the above.
E-liquid ingredients sit inside the wider UK vape knowledge base. For the full picture visit our vaping FAQs hub. Every major UK vape question sits inside.
Back to the Vaping FAQs hub
This article sits inside our complete FAQs knowledge base. Head back to the hub for the full index covering MHRA rules, TPD, the 2025 disposable ban, the 2026 vape tax plus retailer compliance.
More UK vape knowledge basics
Ingredients are part of the wider vaping picture. Our overview on what is vaping covers the full basics from device mechanics to UK regulation. For the strength context our piece on why nicotine strength is capped at 20mg in the UK explains the legal ceiling that shapes every e-liquid recipe. For the MHRA disclosure side our guide on what it means if a vape product is MHRA compliant walks through the notification stamp that every UK product carries.