Popcorn Lung, Diacetyl and Authentic vs Counterfeit Vapes

Prepared by: Basta Vape Editorial Team

“Popcorn lung” is often mentioned in discussions about vaping, although the story began among food-flavouring workers. Which chemical raised concern, and does its detection in some older products mean it is present in every product today?

This article separates scientific findings, market-specific rules and reasonable economic inferences about authentic and counterfeit products.

Short answer

Bronchiolitis obliterans, also called constrictive bronchiolitis, affects the small airways, causing scarring and narrowing that may be permanent. Diacetyl is not its only cause; other settings include some infections, immune-related disease and transplant complications.

Possible symptoms include persistent dry cough, breathlessness especially with exertion, wheezing and fatigue. Cleveland Clinic explains that these overlap with other conditions. Neither coughing nor a history of vaping establishes the diagnosis; assessment may include lung-function tests, imaging and other clinician-selected investigations.

Persistent or worsening symptoms warrant medical assessment. Treatment may relieve symptoms and slow damage, but established scarring may not resolve.

In 2000, NIOSH was asked to investigate obliterative bronchiolitis in former workers at a microwave-popcorn plant. Research pointed to inhaled butter-flavouring vapours at work. The popular name refers to the workplace, not to eating popcorn.

Yes. A study in Environmental Health Perspectives tested emissions from 51 flavoured e-cigarette products and detected diacetyl in 39. Detection was not limited to butter-labelled flavours.

Evidence extends beyond the 2019 report. A 2022 NEJM Evidence case series described four patients with a history of e-cigarette use and biopsy findings of small-airway fibrosis and constrictive bronchiolitis. After assessing alternative causes, the authors considered e-cigarette use the most likely cause.

A 2024 clinical report also described vaping-associated constrictive bronchiolitis based on clinical findings, lung-function testing, imaging and assessment of other causes. Small airways were absent from that patient’s biopsy sample, which limits pathological confirmation in this case.

These clinical reports merit attention, but they cannot estimate population incidence or establish diacetyl as the specific causal agent in those cases. It would be inaccurate either to dismiss the published cases or to generalize the outcome to every user or product.

The 2019 EVALI outbreak is distinct. CDC findings strongly linked the outbreak to vitamin E acetate in some THC products. This does not identify the cause of every vaping-associated lung illness.

In Great Britain, MHRA ingredient guidance lists diacetyl and 2,3-pentanedione among substances not permitted as ingredients in e-liquids. UK rules also require product notification before sale.

An established company has an economic incentive to protect its reputation. Recalls, regulatory consequences and lost trust can be costly, giving it reasons to manage suppliers, formulations and production. Profit incentives can also encourage cost cutting. Effective oversight and accountability influence actual behaviour, so reputation remains an economic consideration rather than a laboratory finding.

When checked through a brand’s official channel, a valid code may support a claim that a package comes from that brand. Check the official website independently rather than relying only on an unknown link printed on packaging; retain the batch details and seller information.

Even an appropriate test reporting no detectable diacetyl applies to the tested sample and the method’s detection limit. It does not establish that the product or its emissions are free of all other risks.

The occupational evidence establishes concern about inhaled butter-flavouring vapours, and diacetyl was detected in some earlier vaping products. Some markets prohibit its addition to e-liquids. Those facts cannot certify every brand or identify the cause of every lung illness.