does vaping cause popcorn lung

July 7, 2026

Does Vaping Cause Popcorn Lung?

The facts about diacetyl, bronchiolitis obliterans and whether UK vapers need to be concerned.

Quick answer: Popcorn lung is not a risk from TPD-compliant UK e-liquids. The chemical responsible: diacetyl: was banned from UK e-liquids in 2016. There have been no confirmed cases of popcorn lung from regulated UK vaping products. The concern was identified early and acted upon before it became a public health problem here.

Popcorn lung is one of the most frequently raised concerns about vaping. Understanding what it is, where the concern came from and why it does not apply to regulated UK products is straightforward once the facts are laid out clearly.

What Is Popcorn Lung?

Popcorn lung is the informal name for bronchiolitis obliterans, a serious and irreversible lung disease. It causes scarring of the tiny air sacs in the lungs, leading to obstruction that cannot be reversed. Symptoms include coughing, wheezing and shortness of breath.

The name comes from an outbreak among workers at a microwave popcorn factory in Missouri in the early 2000s, where prolonged exposure to diacetyl: a butter-flavoured compound used in the product: caused the disease at unusually high rates. The occupational exposure levels involved were far higher than those in everyday consumer use.

What Is the Link to Vaping?

Diacetyl was used in some e-liquid flavourings to create a buttery or creamy taste. A Harvard study published in 2015 detected diacetyl in a significant proportion of flavoured e-liquid samples tested, raising concern that vapers could be exposed to the same compound that had caused occupational lung disease.

This was a legitimate and important finding. The UK responded through the EU Tobacco Products Directive, which came into force in 2016 and banned diacetyl (and the related compound acetyl propionyl) from e-liquids sold in the UK and EU.

UK Regulatory Status

Compound	Linked to popcorn lung?	Permitted in UK e-liquids?	Status
Diacetyl	Yes: direct occupational link	No: banned under TPD since 2016	Prohibited
Acetyl propionyl (2,3-pentanedione)	Yes: similar chemical mechanism	No: banned under TPD since 2016	Prohibited
Acetoin	Lower concern: no direct link to disease at normal levels	Yes: permitted	Allowed; low risk at e-liquid concentrations

Why the UK Risk Is Different from Historical US Cases

The diacetyl cases that prompted the popcorn lung concern were in the US, where regulatory action came later and less completely. In the UK, TPD regulations implemented a proactive ban before any confirmed consumer vaping cases of popcorn lung were established. The regulatory framework here is substantially more protective than in unregulated markets.

Diacetyl exposure level comparison (approximate, relative)

Longer bar = higher diacetyl exposure. Occupational levels caused confirmed disease; UK e-liquids now contain none.

Factory occupational exposure

Disease causing

Pre-2016 some e-liquids

Detectable

UK TPD e-liquids post-2016

Banned: none

Buy from reputable UK retailers. The popcorn lung risk applies specifically to non-compliant products from unregulated sources. Counterfeit or unverified imports may not meet TPD ingredient requirements. All products sold at Celtic Vapours are TPD-compliant and diacetyl-free.

Frequently Asked Questions

There are no confirmed cases of bronchiolitis obliterans attributed to TPD-compliant UK e-liquid use. The regulatory action taken in 2016 preempted what could have been a problem had diacetyl continued to be used in e-liquids. The UK public health community monitors adverse respiratory events from vaping and no cases matching popcorn lung have been confirmed from regulated products.

Ironically, cigarette smoke also contains diacetyl at levels significantly higher than those found in pre-ban e-liquids. Yet smoking is not associated with popcorn lung as a primary outcome (it is associated with COPD, emphysema and lung cancer instead). The 2015 Harvard research made this point: vapers may have been concerned about diacetyl in e-liquids while smokers were simultaneously exposed to far more of it without the same concern being raised.

Prior to 2016, buttery and custard flavours were more likely to contain diacetyl because they used it for authentic taste replication. Since the TPD ban, these flavours must use diacetyl-free alternatives. Reputable UK manufacturers reformulated their products before or at the point of the ban. When buying from trusted UK retailers, custard and butter flavours are as safe from a diacetyl perspective as any other flavour.

Any persistent respiratory symptoms: ongoing cough, unexplained breathlessness, wheezing or chest tightness: should be assessed by a GP. Do not self-diagnose or attribute respiratory symptoms to vaping without medical assessment, as they may reflect a separate condition. If you have been using unregulated or imported vaping products, mention this to your GP as part of the consultation.

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