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? Until recently, there was no FDA oversight whatsoever of e-cigarettes. On May 5, the Food and Drug Administration (FDA) announced it will be extending its oversight authority to include e-cigarettes and other tobacco products. Starting in August, FDA will begin to apply and enforce key provisions of the Family Smoking Prevention and Tobacco Control Act as it relates to the sales, marketing and manufacturing of e-cigarettes. Unfortunately, e-cigarette manufacturers have essentially been given a temporary "free pass" and their products will be allowed to remain on the market for up to three years as manufacturers test their products and submit necessary applications to the FDA for review.

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 John at: November 12, 2017
This article should be updated or removed now that the FDA is regulating e-juice. Also, e-juice is made with vegetable glycerin which may not sound so different than vegetable oil but it is not the same thing and does not cause this disease. The article failed to mention this. It is a shame to see a site like this being so one-sided and vague, disseminating misinformation.
Submitted by BrightDayMiddleOfNight at: September 10, 2017
It's interesting how goofy the people in the comment section are here. Questionioning the authenticity of scholarly scientific journals from Harvard University, no less, our own governments research programs, and nonprofit health organizations. They put in all this hard work for free mostly, so we can be informed. Yet no, they're trials and hours of research means nothing because they believe otherwise. As if the commenters hold any factual counter studies which say this chemical is safe. Personally, thank you lung.org for letting us know about this important health notice. I will now seek organic e-cigarette "juice" for personal consumption.
Submitted by Investigator Charlie at: August 27, 2017
This article is absolute tripe! It is very deceptive to spread misinformation to the public under the guise of "urgent issue for public health" Think for yourself, do your own research, and don't be a sheep. According to snopes, Tobacco cigarettes have long been known to contain diacetyl, e-cigarettes have very little to none at all. Daily exposure to diacetyl from smoking is 750 times higher, on average, than exposure to diacetyl from vaping. In a 2014 study on tobacco consumption, diacetyl, and popcorn lung, the highest concentration in e-cigarettes is lower than the lowest concentration in tobacco cigarettes! Other earlier tobacco studies also found that even the highest levels in tobacco cigarettes were still NOT ENOUGH TO CAUSE POPCORN LUNG in smokers. Source: http://www.snopes.com/vaping-causes-popcorn-lung/
Submitted by Justin at: August 2, 2017
This article is nothing but false information. Ejuice company's have stopped using diacetyl in there juices for a while now. Before you guys right an article at least be educated about what your writing about.
Submitted by Jon at: July 31, 2017
I'm 42 and smoked at least 2 packs a day for the better part of 27 years. I have vaped HEAVILY and consistently for the last 4 years and have NEVER breathed better in my life since I started smoking at 12. Now I am sure there are health risks to any of it but cutting out the multitude of chemicals and carcinogens found in inhaling something that is literally on fire is a step in the right direction. Go on somewhere else with your propaganda...
Submitted by Pertn at: March 25, 2017
As someone working in the flavor industry, this article is pretty much a joke and it undermines the point they are trying to make. The entire flavor industry has stopped using diacetyl as an ingredient. Period. The Harvard study not only makes no distinction between naturally occurring diacetyl (you know, like in butter, cream, buttermilk, etc) and added diacetyl. I can assure you there is no added diacetyl in any of those flavors. Also, they only claim diacetyl is detected but they stop short of saying "at a harmful level". As usual in a lab, they have no way to say if that detectable level is even harmful. There is a much simpler, logical argument to be made here without a flimsy study. The flavoring for e-cigs are just that - flavoring. They are meant to be ingested not breathed in. This article focuses on diacetyl, because it's an easy scapegoat. However, what about benzaldehyde, a key ingredient for almond and cherry? At even a moderate level, it is an irritant. That has a strict legal limit in flavors used for beauty and healthcare, but not for breathing in. That's where your argument should be. The fact is we don't know what effect literally thousands of flavoring ingredients have on the lungs. E-cigs are a powder keg waiting to explode once people who vape start getting sick because of the multitude of flavor compounds being ingested into people's lungs that never should have been in the first place. My employer has walked away from serving e-cig manufacturers for this reason. We may indirectly supply them, through brokers (where we have no control of where the flavors end up), but we will never sell flavor to them directly. Regarding butter flavor, we do use acetyl methyl carbinol and acetyl propionyl because we have literally no other way to provide butter flavor. However, the article says they are harmful with no citation whatsoever, so good job, article author.
Submitted by Modbusters at: February 21, 2017
You know this report reminds of a friend of mine telling me how much more dangerous my E cig is over smoking .as he puts a nic patch in his mouth to tear it open to place the patch on his arm nothing happened he is fine but still smoking that was a year ago my lungs are shot due to smoking and my work history.I am 58 started smoking when I was 14 .but I have not had a cig in over two years . Vapeing can not undo what smoking has done to my lungs .but I have not had to do a breathing treatment every morning like before I have not done any and only used one refill on my inhaler.fact not fiction so all this can be documented from the doctors ecigs got me away from cigarettes and that's a fact it bothers me to see people still smoking and I can't say nothin with the new laws they wouldn't listen any how to me scare tactics going on mixed with denial so if you want facts get ahold of me I got plenty of them .
Submitted by Bob Nulph at: January 18, 2017
This IRKS the HECK out of me, you know why? I have what will eventually be a terminal lung disease or will require a double lung transplant and my disease is of the Idiopathic ("of no known origin") type. So I can't say I was dumb enough to use E-Cigs and poor me I am now sick and it's YOUR fault, not mine..... Sorry, you are still WILLINGLY inhaling and how can you be surprised to end up sick??
Submitted by Rhonda. at: January 12, 2017
Hi...im a emphacema alpha 1 patient. Ive had stopped smoking eventually at the age of 45 from 16 yrs old... i had a nasty infection at xmas which took me off my fee5. I have started usingy ecig... im a bit concerened qbout the popcorn lung tbh due to the alpha 1 ....
Submitted by Ltray at: November 25, 2016
My wife used e cigarettes and almost died getting a double lung transplant trying to help her quit ! They r killing n nobody cares!!!
Submitted by mike at: September 4, 2016
ok so you say flavors that has this toxin which flavors?
Submitted by TonicBoom at: July 8, 2016
As a manufacturer of e-liquids for electronic cigarettes I am very well versed in this issue. With just a small amount of research this entire article can easily be discredited. First off most every major flavor manufacturer that companies like mine use to manufacture e-liquids went through the process of reformulating their flavors concentrates to remove diacetyl last year and years prior. 99.9% of these flavor concentrates DO NOT CONTAIN DIACETYL! However conventional cigarettes do still contain diacetyl. These workers who contracted popcorn lung during their work were also exposed to pure concentrated diacetyl which no person in this country will ever be exposed to due to strict OSHA regulations. This entire article is propaganda used to scare people away from electronic cigarettes which CDC research and data clearly shows is much safer and saves lives. The Royal College of Physicians in the UK has backed the use and promotes the use of electronic cigarettes as a much safer and healthier alternative to traditional cigarettes and acknowledged the fact that these devices save lives. Unfortunately here in America corporate interests and lobby groups use articles like this push their own interests. Wake up America and realize that these entities don't have your best interest in mind.
Submitted by NOTsmokeCharlie at: July 8, 2016
Wisegeek 1 gives this definition of diacetyl: A naturally occurring chemical that is produced as a byproduct of yeast during the fermentation process. Used in a wide variety of food products, it is best known as a flavoring in microwave buttered popcorn. Most recently, diacetyl has earned a bad name for being the probable cause of several popcorn factory workers developing what has been dubbed ‘popcorn lung’, or bronchiolitis. This is a rare and serious fixed obstructive lung disease. In the 1990’s, factory workers in a microwave popcorn plant contracted bronchiolitis, also known as ‘popcorn lung’. It was generally believed that this was the result of inhaling a powdered form of diacetyl, in very high concentrations, which is used in the butter flavoring for the popcorn. While it is generally believed that the cause of popcorn lung was inhalation of powdered diacetyl, this has yet to be proven, as we will see shortly in the information provided by the CDC. It is important to note that the FDA has posted the following statement about the consumption of diacetyl on their website 2, Diacetyl is added to some foods for flavoring purposes. It is metabolized in mammals, is of low acute toxicity, and the no-adverse-effect level is estimated to be less than .3mg. There is no evidence on the available information on diacetyl that demonstrates or suggests reasonable grounds to suspect a hazard to the public when they are used at levels that are now current or that may reasonably be expected in the future. The FDA has listed Diacetyl on their Generally Regarded as Safe (GRAS) list of food additive products, yet they have not made a statement regarding the safety of the inhalation of diacetyl in vapor form. As mentioned above, it hasn’t been proven that diacetyl was the cause of the popcorn-lung, as seen by the article published by the CDC 3 to address their views on diacetyl titled Flavorings-Related Lung Disease in which they state Diacetyl is a chemical that was found to be a prominent volatile constituent in butter flavoring and air at the microwave popcorn plant initially investigated. Workers in microwave popcorn manufacturing are exposed to many materials besides diacetyl. Thus, initial studies in a total of 6 microwave popcorn plants were not able to definitely determine if diacetyl exposure contributed to lung disease or was a marker for other hazardous substances that contributed to disease. Current evidence, however, points to diacetyl as one agent that can cause flavorings-related lung disease. While other flavoring ingredients may also play a role. Meaning, while they cannot prove that diacetyl was the cause of the disease, they do consider it a primary area of concern. The diacetyl inhaled by these factory workers was in powder form, used to add a buttery flavor to the microwave popcorn they were producing. However, when vaping there is obviously no powder being inhaled, so does this concern relate to vaping? It may not be common knowledge, but diacetyl is a common ingredient in tobacco, and has been for over 50 years. Meaning, those who have been smoking cigarettes, have been inhaling diacetyl this whole time. The Critical Reviews in Toxicology 4 group conducted a study simply titled Diacetyl where they concluded, Diacetyl exposures from cigarette smoking far exceeded occupational exposures for most food/flavoring workers. This suggests that previous claims of a significant exposure-response relationship between diacetyl inhalation and respiratory disease in food/flavoring workers were confounded. Further, smoking has not been shown to be a risk factor for bronchiolitis (popcorn lung). To summarize their findings, they found that the levels of diacetyl in tobacco were significantly higher than those found in the factories where the popcorn lung was contracted, bringing into question the diacetyl as the cause of the condition. Further, they found that smoking cigarettes, regardless of the higher levels of diacetyl has not been shown to cause popcorn lung. Looking at e-juice in relation to tobacco levels of diacetyl the Nicotine & Tobacco Research 5 group conducted a study Evaluation of Electronic Cigarette Liquids and published these results, “The purpose of this study was to evaluate sweet-flavoured electronic cigarette (EC) liquids for the presence of diacetyl (DA). DA was found in 74.2% of the samples. They were lower than the strict safety limits for occupational exposure and 110 times lower compared to smoking respectively.” This tells us first, that there is diacetyl in analog cigarettes at 110 times higher levels than those found in the e-juices they studied. Secondly this tells us the amounts they found in the e-juice were within the safety limits of exposure. To summarize, studies like those conducted above show that there is a significantly higher amount of diacetyl exposure from smoking than there is in the factories where the production workers got sick, presumably (but not proven to be) due to exposure to diacetyl inhalation. There are also no documented cases of popcorn-lung being developed from smoking. That being said, when you buy from Mt Baker Vapor we use the highest quality, finest ingredients from right here in the US, which means we can make sure that they are all diacetyl free. We choose not to purchase from suppliers that use it in their flavoring. As always, I encourage everyone to educate themselves. Read the studies and information listed in the references below, and learn more about the data surrounding the subject of diacetyl. Come back next week when we look at the subject of Nicotine absorption levels and how they are affected by what we use to vape, and the way we vape. Until then, we look forward to your questions and comments. Vape on! Written by: Michelle Harnden
Submitted by The Mad Vaper at: July 8, 2016
Unfortunately the author of this poorly researched yet regurgitated article neglected to tell us that the levels of diacetyl in e-liquids is thousands of times less than that which is present in traditional cigarettes. In fact, most responsible e-cig liquid manufacturers use flavorings that contain no diacetyl at all. This is yet another scare tactic used by an agency that is partially funded by donations from the tobacco and pharmaceutical industries who want the vaping industry to disappear so that they can once again corner the market to continue killing with cigarettes and offer ineffective methods to "quit" smoking. It's time to stand up to Big Tobacco and Big Pharma and tell the truth to the American public. Stop doing what those who hold the purse strings of your organization say and promote your mission you save lives.
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