A 2015 study by Harvard generated a lot of interest among vapers. The study found diacetyl and/or the two diacetyl analogs, acetoin and 2,3-pentanedione (also called acetyl propionyl), present in 47 out of 51 e-liquid flavors tested. Diacetyl and its analogues are naturally occurring compounds that, when heated and inhaled, have been linked to an extremely serious, irreversible and potentially fatal lung disease called bronchiolitis obliterans.
The connection was first discovered in workers at a microwave popcorn manufacturing plant who were exposed to large vats of boiling butter flavoring that contained significant amounts of diacetyl and since then, bronchiolitis obliterans has gone by the nick name “popcorn lung.”
It should be noted that diacetyl can also be found in cigarette smoke. Given the fact that vape juice can and should be crafted without this compound, electronic cigarettes now make this an avoidable risk. The Harvard study has been used to demonize vaping when, in fact, it shows yet again how vaping has the potential to reduce the harm of smoking.
As the owner of Kai's Virgin Vapor since 2010, I have learned a lot about diacetyl. We established all of our laboratory and testing protocols with the help of a Ph.D. chemist who worked for us for several years creating the processes and protocols we have in place. We also have an in-house GCMS machine in our lab. GCMS stands for gas chromatography–mass spectrometry, a sophisticated analytical method for analyzing compounds present in a given sample. GCMS machines are commonly used in forensic science as well as at airport security check points and are known for their extreme accuracy in detecting even trace elements in a given sample.
Our GCMS testing equipment. The doodle on the whiteboard is the chemical composition of nicotine. : )
We have tested all of our flavors for the presence of diacetyl, acetoin and pentanedione. Even though we have our own GCMS machine for testing on the fly, we prefer to use an outside laboratory that specializes in e-liquid analytics to perform our testing in order to give our customers the assurance that our results are completely trustworthy and transparent. We continue to perform regular, ongoing testing of our flavors to ensure our flavor manufacturers have not changed their formulations and to ensure our test results from batch to batch since organic flavors will naturally have some variation because they are derived from real foods.
We have Certificates of Analysis showing all of our flavors do not contain these compounds with a detection limit of a fraction of a part per million. We are very proud of these results and invite you to take a look for yourself!
We also know that it can be confusing to read a lab test result without a little help so we wrote an article to help you understand exactly what you are looking at. As we said, we're proud of our results and we want to make sure you can understand just how clean our vape juices are!
Our GCMS machine in action.
While I am proud of the steps that we have taken to ensure we eliminate this risk for our customers, I am also disturbed by the large number of vape juice companies that are still including these compounds in their e-liquids. Fortunately, consumers are becoming more educated and are starting to ask vape juice manufacturers if their e-liquids contain these compounds. However, asking may not be enough.
Many e-juice companies will claim their products are diacetyl free because their flavor manufacturer told them that. We do not take our flavor supplier's word for it, we test it ourselves. Why? Our testing has shown that many flavor manufacturers who specifically claim and label their flavorings as "diacetyl free" may be greatly misleading their vaping customers. A product that contains less than 1% diacetyl can be labeled "diacetyl free" under U.S. food labeling laws. That may be fine in a food product, but 1% diacetyl translates to a whopping 10,000 parts per million, an absolutely unacceptable level even when diluted in an e-liquid.
To make matters worse, even when I have confronted some of these flavor manufacturers with a laboratory test from an independent lab showing their flavors were full of diacetyl, they refused to accept a return of their product despite their misrepresentation, refused to discontinue selling the flavor with the label “diacetyl free” and continued to actively promote their product to other e-juice manufacturers with the assurance that the flavors did not contain diacetyl.
Whether intentional or not, our findings have clearly shown that a flavor manufacturer cannot be trusted to accurately represent the content of these compounds in their products. So when you ask your e-juice manufacturer if their flavors contain diacetyl, you also have to ask them how they know. Always insist on laboratory testing rather than relying on a flavor manufacturer’s word.
Also, don’t forget to ask about the two diacetyl analogues, acetoin and pentanedione. Not long ago, I asked a senior executive at one of the major e-juice manufacturing companies in the United States if their e-liquids contained diacetyl. He told me no. When I asked about pentanedione, I saw a cloud pass behind his eyes and I could tell that he didn’t know what I was talking about but he still answered no. When I took the sample he gave me back to our lab, my suspicions were confirmed. He was right about there being no diacetyl, but I found massive, unsafe levels of pentanedione instead. There’s not much point beyond a marketing gimmick in removing diacetyl if you fail to make sure you don’t have a pentanedione or acetoin problem as well.
Why do e-juice manufacturers include these compounds to begin with? The simple answer is, they taste good! A diacetyl-free caramel is just not going to have that ooey-gooey mouth feel that a caramel flavor loaded with diacetyl is going to have. It gives vape juice manufacturers a competitive advantage to include diacetyl because most consumers won’t know to ask and will prefer the taste.
As a vaper, you should also be aware that while a lot of people know that diacetyl can be present in buttery or creamy or custard type flavors, it can also be present in many other flavors that you may not suspect. We have found high levels of diacetyl in everything from coffee to candy to bakery and even quite a few fruit flavors. Avoiding “creamy” type flavors is simply not enough to avoid diacetyl.
Since the Harvard study, many people began calling for regulation to keep diacetyl, acetoin and pentanedione out of vape juice and the FDA is finally moving in that direction although it has yet to set exact limits on these compounds. I strongly support regulation but I also feel it is sad that the vape juice industry as a whole did not take the steps to police itself. While I haven't done an exhaustive search myself recently, our customers tell us that we are one of only about a half a dozen vape juice manufacturers who publicly post test results for diacetyl.
The dangers of diacetyl have long been known in the industry. The Harvard study isn’t anything new. Every e-juice manufacturer should already be testing for these things. It’s ethically, morally, legally and professionally the only right thing to do. Until regulation does make this issue a thing of the past, be sure to demand your vape juice manufacturer test for these compounds, publicly post their test results in a way that you can understand them and take the necessary steps to eliminate these compounds.