Does vaping cause popcorn lung?

  • E-cigarettes don’t cause the lung condition known as popcorn lung
  • There have been no confirmed cases of popcorn lung reported in people who use e-cigarettes
  • E-cigarettes are one of the tools that can help people who smoke to stop

What is popcorn lung?

Popcorn lung (bronchiolitis obliterans) is an uncommon type of lung disease, but it is not cancer.  It’s caused by a build-up of scar tissue in the lungs, which blocks the flow of air.

A possible link has been suggested between the disease and a chemical called diacetyl. More research is needed to find out if they’re connected.


What causes popcorn lung?

A group of popcorn factory workers developed the condition, leading to the name ‘popcorn lung’. They had breathed in diacetyl, as it was used as a flavouring in the popcorn. It was not related to use of e-cigarettes.

Although bronchiolitis obliterans is sometimes called ‘popcorn lung’, it can be caused by a number of different things. For example, it can happen after an infection, if it damages the lungs. Or after breathing in chemicals that irritate the lungs and cause damage.


What does the evidence really say about diacetyl and e-cigarettes?

Some of the liquids in e-cigarettes used to contain diacetyl. This led to the idea that e-cigarettes might cause popcorn lung. In the UK, diacetyl was banned in e-cigarette liquids under the EU Tobacco Products Directive (TPD) in 2016. So, e-liquids sold in the UK shouldn’t contain diacetyl. 

And there have been no confirmed cases of popcorn lung linked to e-cigarettes.


Are e-cigarettes harmful in other ways?

E-cigarettes are a relatively new product – they aren’t risk-free and we don’t yet know their long-term impact. Children and people who haven’t smoked shouldn’t use them.

But research so far shows that vaping with legal e-cigarettes is less harmful than smoking, and can help people to stop smoking. For the best chance of quitting, get support from a free, local stop smoking service, who can help you find the right tools for you.


We regularly review new research on the causes of cancer to make sure our information is up to date and based on the best quality evidence. We develop our information by looking at lots of research carried out over many years. So, although new research comes out all the time, it is unlikely that one new study would change our position on a topic.  

Some studies are better than others at telling us about how different factors affect cancer risk. These are some of the things we consider:

  • Did the study look at cells, animals or people?

Studies in animals and cells can help scientists understand how cancer works, but they can’t always tell us how it’s relevant to humans. So we focus on studies in people.

  • How big is the study and how long did it go on for?

Studies on small numbers of people aren’t as reliable, because results are more likely to happen by chance. And studies that only follow people for a short amount of time can miss long-term effects. So we mainly look at studies that follow thousands of people over many years.

  • Did the study account for other factors that could affect someone’s cancer risk?

There are lots of factors that can affect someone’s risk of cancer. Studies should take known risk factors into account. For example, if a study is looking at air pollution and lung cancer, it should also look at whether participants smoked.

  • Where is the study published and who funded it?

It’s important to see if a study is published in a peer-reviewed scientific journal. This means that other experts have checked the results. It’s also important to know who funded the study, as this can affect the findings. For example, Cancer Research UK disregards research funded by the tobacco industry.

How to find accurate information on cancer

Sometimes news outlets exaggerate stories about cancer. It’s helpful to think about some of the questions above to judge a news story. But the most important thing is to get information from a trusted source– for example our website and the NHS.

One way of knowing if you can trust health information is by checking if the Patient Information Forum (PIF) has accredited it. The PIF makes sure that information is based on up to date evidence and is high quality.

The Patient Information Forum tick looks like this.

Patient Information Tick

You can read more about spotting fake news on cancer on our blog.

Allen, J. G. et al. Flavoring Chemicals in E-Cigarettes: Diacetyl, 2,3-Pentanedione, and Acetoin in a Sample of 51 Products, Including Fruit-, Candy-, and Cocktail-Flavored E-Cigarettes. Environ. Health. Persp. 124, 733–739 (2016).

Centres for Disease Control and Prevention. Fixed obstructive lung disease in workers at a microwave popcorn factory--Missouri, 2000-2002. Morb. Moral. Wkly. Rep. 51, 345-347 (2002).

UK Health Security Agency. Clearing up some myths around e-cigarettes (2018).

The Tobacco and Related Products Regulations 2016, paragraph 36(5)(d) [Accessed November 2021]

UK Discussion Paper on Submission of Notifications Under Article 20 of Directive 2014/40/EU, Chapter 6 – Advice on Ingredients in Nicotine-Containing Liquids in Electronic Cigarettes and Refill Containers [Accessed November 2021]


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