The short version
- Vaping is not water vapour and it is not harmless. The aerosol carries nicotine, ultrafine particles, carbonyls and flavour compounds that were tested for eating, not for breathing.
- If you have never smoked — and especially if you are under 18 — there is no upside. You are taking on an addiction and a risk for no offsetting gain.
- If you smoke, switching completely is a substantial improvement. Not neutral, not harmless, but clearly better than continuing to smoke.
- Doing both is the worst outcome. Dual users show respiratory risk close to smokers, not close to vapers.
- Second-hand aerosol is real but much smaller than second-hand smoke. It matters most in cars and small rooms, and most of all to children who cannot leave.
Why this page is careful about the comparison
Most writing on vaping picks a side. One camp says it is nearly harmless and a public health win; the other says it is a new epidemic. Both distort, and the distortion does measurable damage.
In 2026, 62% of young people in Great Britain believed vaping is as harmful as smoking or worse. That belief is wrong, and it is not harmless to hold: a smoker who thinks switching gains them nothing has no reason to switch. Overstating vaping harm keeps people smoking.
Understating it has its own cost, and it landed on a generation of children who took up nicotine because it came in mango. So this guide holds both: vaping is meaningfully harmful and meaningfully less harmful than smoking, and which of those matters more depends entirely on who is asking.
It depends who you are
You have never smoked
There is no case for starting. You would be taking on nicotine dependence and an inhaled exposure with no long-term safety record, in exchange for nothing.
You smoke and want to stop
Switching completely is a real improvement and the NHS supports it as a quit route. The word doing the work is completely.
You do both
This is the outcome to get out of. On respiratory measures dual users look far closer to smokers than to people who only vape.
You are a parent
The two things that matter are the car and the house. Smoke-free law does not cover vaping, so those are your call, not the law's.
Four things worth knowing
Nicotine salts are why it got so addictive so fast
They make high nicotine concentrations smooth enough to inhale deeply without the harshness that used to limit intake. A modern pod can deliver nicotine at a rate a cigarette never did.
The lung injury outbreak was a different thing
EVALI in 2019–20 was strongly linked to vitamin E acetate in illicit THC cartridges, not to regulated nicotine vaping. It is often cited as though it were the same subject. It is not.
Ventilation matters more than people expect
The same session in a sealed car and in a ventilated room produce bystander exposures that differ by an order of magnitude. The estimator shows the difference.
The UK market changed in June 2025
Single-use disposables are banned. Youth disposable use fell from 69% to 13% in three years — though how many young people vape has not fallen nearly as much. What changed, and what it did.
If you want to stop vaping
- Nicotine withdrawal is real: irritability, poor concentration, low mood and disturbed sleep, worst in the first week and easing over two to four.
- Local NHS stop smoking services support people quitting vaping too, and are free.
- Stepping down nicotine strength gradually tends to work better than going from a high-strength pod to nothing.
- If you switched from smoking and are struggling to come off vaping, staying on the vape is still the better of the two. Do not let a failed quit push you back to cigarettes.