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Popcorn Lung: A Dangerous Risk of Flavored E-Cigarettes

Outline of lungs over enlarged picture of a popcorn kernel

Over a decade ago, workers in a microwave popcorn factory were sickened by breathing in diacetyl—the buttery-flavored chemical in foods like popcorn, caramel and dairy products. While this flavoring may be tasty, it was linked to deaths and hundreds of cases of bronchiolitis obliterans, a serious and irreversible lung disease. As a result, the major popcorn manufacturers removed diacetyl from their products, but some people are still being exposed to diacetyl - not through food flavorings as a worksite hazard, but through e-cigarette vapor.

When inhaled, diacetyl causes bronchiolitis obliterans - more commonly referred to as "popcorn lung" - a scarring of the tiny air sacs in the lungs resulting in the thickening and narrowing of the airways. While the name "popcorn lung" may not sound like a threat, it's a serious lung disease that causes coughing, wheezing and shortness of breath, similar to the symptoms of chronic obstructive pulmonary disease (COPD).

Even though we know that diacetyl causes popcorn lung, this chemical is found in many e-cigarette flavors. It is added to "e-juice" liquid by some e-cigarette companies to complement flavorings such as vanilla, maple, coconut and more. So while diacetyl was swiftly removed from popcorn products since it could cause this devastating disease among factory workers, e-cigarette users are now directly inhaling this harmful chemical into their lungs. In fact, researchers at Harvard found that 39 of 51 e-cigarette brands contained diacetyl. The study also found two similarly harmful chemicals—2,3 pentanedione and acetoin—present in 23 and 46 of the 51 flavors it tested. And roughly 92 percent of the e-cigarettes had one of the three chemicals present.

Rows of amber glass bottles and vapor coming off of one in the corner

How is this possible that many Americans are unknowingly inhaling chemicals that can cause traumatic respiratory harm? Unfortunately, the Food and Drug Administration (FDA) announced in July 2017 that it would delay until 2022 the requirement that e-cigarette companies submit their products, including all ingredients, to FDA for review. The American Lung Association and our partners filed a lawsuit against the FDA for this delay, but for the meantime, these products remain on the market until FDA begins to enforce the provisions.

This is an urgent issue for public health, especially given the popularity of e-cigarettes among youth. The American Lung Association believes it's imperative that FDA act quickly to require that diacetyl and other harmful chemicals be removed from e-cigarettes.

Remember, the American Lung Association is here to save lives by improving lung health and preventing lung disease. Read our public education statement on E-cigarettes and Lung Health, and when you're ready to quit tobacco for good, we're here to help.

Related Topics: Tobacco & Smoking, Health & Wellness,

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Submitted by Anonymous at: March 6, 2020
E-cigarettes will not cause popcorn lung there is more diacetyl in a cigarette then e-cigarette juice
Submitted by jj at: January 29, 2020
Hi, I'm Jermel from Blue Springs School District and liked this article and for an assignment i am supposed to contact someone for help on why vaping is detrimental to health. We are writing a script as if we are talking to a young patient vaping and trying to get him to stop. If you could contact me back that will be greatly appreciated my email is
Submitted by Vapes4eva at: January 20, 2020
This was debunked back in 2015, please update your information. First off, e liquid manufacturers stopped using diacetyl, the chemical in question, second: even the brands that did had in concentrations so low that you have to vape 60ml a day for 1.5 million years to be at risk, and finally, cigarettes contain 750x more diacetyl than any e cigarette ever did and there have been no reports of popcorn lung from smoking
Submitted by Arom at: January 19, 2020
If your organization was truly for lung health you wouldn't want to kill something that has huge benefits by switching adults to a better alternative. Look at the research in the UK, they have vape shops in hospitals Popcorn lung is a myth, there is 100 times more diacetyl in combustible cigarettes than there is in E Juice. It's annoying that such organizations are spreading misinformation this willfully. Makes one wonder what their alterior motive is
Submitted by @MichelleHughes_ at: January 19, 2020
I can't seriously believe you are sharing this information on twitter today when it has been debunked scientifically. Seriously, whomever is control of your media on twitter should be fired. Not a single smoker has been diagnosed with popcorn lung and cigarettes have about 98% more diacetyl than eliquid.
Submitted by DaveMan50 at: October 3, 2019
Thanks for watching out!
Submitted by Mike at: September 10, 2019
The truth that's not told here is that in order to be exposed to the levels of diacetyl that caused the disease in the factory workers, one would have to vape 2oz(A LOT) every day for...1.5million years. Yeah, you read that right. ALSO what's not told is that cigarettes contain roughly 750times MORE diacetyl than any vape liquid. There has not been a smoke related case of 'popcorn lung'. EVER! In the HISTORY OF THE PLANET! This is mainstream media using half-truths and misleading 'facts' to manipulate the public. Get your crap together and print some truth...
Submitted by Chanimal at: December 6, 2018
As a Christian I believe that We should treat our bodies like a temple and we shouldn't do things that could put us at a risk of harm.
Submitted by xQueenAryaStark at: December 6, 2018
Did Big Tobacco pay you to write this?
Submitted by Jake at: November 27, 2018
I would just like to point out that Harvard tested 51 flavors of vape but only from 8 different brands. Also there are NO know cases of vaping causing popcorn lung. Check medical reports people.
Submitted by Brandon at: November 21, 2018
Then the problem should be solved. Just remove the diacetyl. I'm a vaper myself and nicotine itself should not cause popcorn lung or cancer. 😎👍✌
Submitted by Butterflies 2018 at: September 18, 2018
Is cigarettes safer than vaping?
Submitted by Rey at: August 20, 2018
The article written about diacetyl is so flawed that it's laughable. 1) They focus on one chemical that caused brochilitis obliterans on a few popcorn factory workers, who are exposed to many other chemicals, than narrowing it down to diacetyl is ridiculous. 2) Throughout the entire article, no diacetyl content per cigarette was ever mentioned, ( average ecig per volume was 9mcg, average cigarette 335.9mcg (Fujioka and Shibamoto study) ...750 times more than ecig. Now, it doesn't take a genius to figure out that if cigarettes contains 750 times more diacetyl, then why aren't there more popcorn lung cases as they postulate? Vey flawed study designed to scare converts to a safer alternative.
Submitted by wazzuno1 at: August 6, 2018
After reading this article and all of the responses. I found one individuals response worthy of re posting because it was like reading my own thoughts. I will re-post only the phrase that pretty much says it all. There is no argument to it. Submitted by Transform2fit at: February 27, 2018 It is really quite simple. The ONLY thing that belongs in your lungs is fresh clean air. Everything else is going to have some negative effects on your lungs and your overall health. Wake up! Get healthy!
Submitted by lh at: July 30, 2018
I would like the references for your statement "Over a decade ago, workers in a microwave popcorn factory were sickened by breathing in diacetyl—deaths and hundreds of cases of bronchiolitis obliterans". I have found information for 8 cases with this factory.
Submitted by Nicole at: July 11, 2018
Okay, I have to say this. Not that I want "popcorn lungs" BUT I don't want 4,000PLUS poisons like rat poison, ohhh & others like COPD-emphysema and chronic bronchitis, Lung Cancer, plus other cancers, Coughs, colds, wheezing & asthma, shortness of breath from a flight of stairs. Yeah, I'll vape until I am finished lowering my nicotine & will be 100% smoke free from either! It's definitely the lesser of two evils...
Submitted by DanCRT at: July 5, 2018
Read these posts by person that have no medical training. Hope to see them in hospital as they will keep me working for years to come.
Submitted by Bkibbey at: June 2, 2018
How is this direct assault on science still up? Continuing to promote this puts you in the reasoning camp of anti-vaxers and the like. OK, fine, what you are doing is leaving out information on dosage, not outright lying. For instance, as you have to know if you ever looked into this to any degree, that cigarette smoke also contains this same chemical, and that anyone who has smoked has inhaled MASSIVELY higher quantities of it than they ever could in a lifetime of heavy vain of only vapes flavored with this chemical. Yet, no smoker in all of history has ever been diagnosed with popcorn lung. The level of exposure from vaping is so low its beneath negligible. But, hey, who cares that some of us for the first time in our lives are completely free of cigarettes because we now vape (going on six years for me, though I never kicked smoking before for more than a few months). Who cares if there are others like me who'd cease exposure to the 200 plus toxic chemicals in tobacco smoke to vape and expose themselves to know actual health risks outside of those related to nicotine, and that in SIGNIFICANTLY lower doses than they get from smoking. Because that is not acceptable. That does not fit your personal religious faith under which any form of dependence is a sin that must be exterminated, either through giving it up or dying. Better the sinners suffer with cancer if they refuse to convert to your faith. The fact that the American Lung Association still hosts this assault on evidence-based science is simply shameful.
Submitted by mattshel420 at: April 4, 2018
i think some form of good vg or pg should be made based on what we know. then it needs to be dispensed for cheap or people are just going to keep getting harmful vapors
Submitted by Transform2fit at: February 27, 2018
I find it ridiculous how anyone would want to justify vaping. It is really quite simple. The ONLY thing that belongs in your lungs is fresh clean air. Everything else is going to have some negative effects on your lungs and your overall health. Stop trying to justify this ridiculous habit. This comment is not for the writers of the original article but all of those trying to poke holes in the article. Vaping is not healthy, vaping is not safe, vaping will have a negative effect on your life and you are not just effecting yourself but all those around you. Wake up! Get healthy!
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