Thanks to a widely published and hugely fear mongering paper by Harvard, Diacetyl is back in the headlines among the vaping press. I'm not going to attempt to tell you anything really new about Diacetyl (DA from here on in) but I would like to highlight some of the really glaring issues with both the vaping and anti-vaping community getting all worried about this chemical in their liquids (or not, as the case may be).
To date, the Wikipedia entry for DA points to one story with concerns about DA with regards to it being potentially harmful when inhaled (https://en.m.wikipedia.org/wiki/Diacetyl#Safety). The whole issue appears to be based on a single study: Kreiss et al, N Engl J Med 2002; 347:330-338 (http://www.nejm.org/doi/full/10.1056/NEJMoa020300#t=abstract). It's linked to the now infamous 'popcorn workers case', some of whom were found to have bronchiolitis obliterates (OB) which the press referred to as 'popcorn workers lung' in their reports for this case.
Popcorn Lung is, it turns out, an incredibly rare and hard to diagnose condition. In this instance, it was felt, the inhalation of a powder containing DA was the reason for these 'otherwise healthy'
workers contracting the condition. The study comprised medical tests (lung function etc) and an assessment of occupational exposure to respirable dust and volatile organic compounds.
The paper concludes: …” The excess rates of lung disease and lung-function abnormalities and the relation between exposure and outcomes in this working population indicate that they
probably had occupational bronchiolitis obliterans caused by the inhalation of volatile butter-flavoring ingredients.”
It should be noted that the authors state :“Analysis of air samples from the mixing room identified more than 100 volatile organic compounds. There were no known occupational causes of bronchiolitis obliterans identified among these compounds or in the plant at large. Diacetyl (2,3-butanedione), a ketone with butter-flavor characteristics, was the predominant compound isolated from air samples.”
Note: diacetyl is included in the list of compounds that are not known to cause OB
Simply put, there is not enough information about this case to really conclude any concrete details here. Remember this was not a scientific test under perfect lab conditions. What was the health history of the workers? How much of the chemical was inhaled? Did all or only some of the workers exposed contract the condition? How long and over what period did they inhale the substance? We have no idea, as the vital consensus of information is simply missing or not printed.
Interestingly, the study found that quality-control workers—a group of individuals showing higher rates of impaired lung function—may have been exposed to volatile flavouring ingredients which were qualitatively different from those to which the other workers were
exposed as a result of the very high temperatures used in the ‘popping ‘of microwave popcorn.
The study does not address the short-term/acute exposure to very high levels of volatile organic compounds in operations involving adding flavourings to heated tanks. The effects of acute exposure may be very significant in this case.
Popcorn production involves the use of flavouring and also food colouring. The use of artificial colouring agents in food is controversial, do they cause adverse health effects when inhaled?
Does anyone else find it slightly strange that this fairly common chemical, used to make a buttery flavour in foods, has only one loose-on-the-details case connected with it causing public health
worries? This cannot be the only popcorn factory that has ever existed which uses DA. If the connection between DA and Popcorn Lung was so clear cut, surely cases would be more abundant? We would be looking at a public health epidemic as the multitude of popcorn industry factories, the butter and margarine makers all desperately tried to explain why all their workers were getting sick with this fatal and incurable condition. Can I just remind readers that it was apparently the inhalation of a powder containing DA that caused Popcorn Lung in the Kreiss study? They are called e-liquids for a reason...
Respirable Dust is that fraction of inhaled airborne particles that can penetrate beyond the terminal bronchioles into the gas-exchange region of the lungs; it is a notorious and well documented occupational hazard.
Fibrous dusts have been shown to present special health problems primarily related to the shape of the particles. It’s a fairly safe bet that airborne dust from popcorn production will contain some sharp, fibrous material as it’s produced by physical rupturing of the hard (fibrous) corn husk. The effects of chronic exposure to relatively high levels of respirable dust hasn’t been considered—I think this omission represents a fundamental flaw in the study.
The shape, chemical composition and particle size distribution of the respirable dust fraction hasn’t been taken into consideration although it is known that hard, fibrous fine dusts (think
asbestos) are particularly injurious to health.It is also possible that respirable dust could also produce antagonistic effects in combination with other materials present, for example, volatile organic compounds.
There appears to be a correlation between inhalable dust levels and volatile organic compound concentrations—areas where highest DA levels were measured also show highest levels of respirable dust and vice versa. Organic compounds have been implicated as a possible causative agents for OB, yet no attempt has been made to correlate respirable dust level and incidents of the disease despite the pollutants well know adverse health effects.
We the vaping community need to hold our hands up a little here. We were the ones who really highlighted the issue of DA in e-liquid based on, well, not very much. The clear science behind DA and its possible harmful effects do not exist in sufficient quantity for any conclusion to be made.
You cannot make an assumption or guess based on a lack of evidence for something, this is simply not how science works. In theory, with provable cause and effect, you write your paper, show your workings and have it peer reviewed. To date, this hasn't happened with diacetyl at all let alone within e-liquids.
The Harvard paper found small amounts of DA in some of the e-liquids they tested the chemical for. They unhelpfully didn't highlight that cigarettes have far greater amounts of the chemical in
thereby skewing the results to look much worse for e-liquids than they actually are.
As I type this, there is an ongoing case (the first of its kind that I'm aware of) of an e-liquid company being taken to court for producing e-liquids with DA and AP in: http://legalnewsline.com/stories/510649694-five-pawns-sued-over-allegedly-false-claims-about-e-liquid-products
Now I am not affiliated with Five Pawns in any way, though I have vaped some of their liquids and enjoyed them in the past. To take a company to court for false advertising is one thing, but to take them to court on the grounds that either DA or AP is harmful to the consumer surely requires the burden of proof of such claims from the prosecution? Perhaps conclusive, comprehensive evidence can be produced out of this case which once and for all proves DA in an e-liquid does or does not pose a health risk.
Why You Shouldn’t Draw Conclusions from a single Scientific Study.
The papers I have read that attempt to link electronic cigarette use with lung disease use the
Kreiss study as their basis. Not only does the article contain an untested hypothesis, but it appears that it’s the only paper available on the subject. As it can be seen from the graphic
above, more often than not, single studies contradict one another. You could cherry-pick a study to support what ever point you’ve decided to ‘prove’, it’s patently obvious that no
scientifically robust conclusion can be drawn from a single study.
Articles like the Harvard paper (Joseph G. Allen et al) do not follow any stages of the scientific
method. They are fallacious because they are based on an assumption that is not proven (DA inhalation causes OB) and this renders them meaningless. Not even wrong.An alternate approach would be to turn the issue on its head: Examine any of the thousands of industrial processes where workers are exposed to diacetyl and do not suffer OB. The hypothesis: “Occupational exposure to DA is not related to obliterative bronchiolitis” would be easy to test and will likely have a mass of data in support of it.
To date, there has been zero cases of an ecig user contracting bronchiolitis obliterates. Diacetyl is recognised as safe both within Europe and America. There is no clear evidence the chemical is
harmful to public health and until further testing is done it is irresponsible to say otherwise. Bad
science used to support a biased position can have devastating effects on the community.
Bad Science and Scaremongering: Study links e-cigarettes to incurable disease called 'Popcorn Lung'
Predictably, widespread news articles refer to the Harvard study as ‘proof’ of a link between
diacetyl inhalation and obliterative bronchiolitis. This type of misinformed, sensationalistic, propaganda would be laughable if it wasn’t for the fact that some people do actually believe it and it’s in danger of being seen as received wisdom if repeated often enough.
Press articles which are so ill-informed, contrived and biased seem to be a deliberate attempt to mislead and discredit the use of ecigarettes. If this is the case, it begs the question: Cui Bono?: who benefits? Who would benefit by e-cigarettes being banned on health grounds and the subsequent collapse of the vaping industry? What industry has suffered most because of the rise in popularity of vaping? It appears sales of traditional nicotine replacement therapies have taken a bit of a dive recently…http://vaperanks.com/?p=708
These products are made by GlaxoSmithKline—quintessential Big Pharma —and they stand to lose millions in future as the popularity of vaping continues to grow.
What is Tokenvape's stance on Diacetyl?
From the start I wanted our e-liquids to be DA free and we have endeavoured to do that. A lot of
the flavour manufacturers know that ecig companies want their liquids free from this chemical, just in case. As a result most are reformulating their flavourings to suit the needs of their customers. Testing of e-liquids is available at some cost to the manufacturer. I support this in principle as it gives concerned customers peace of mind to see test results. This is something we have been looking into and will be doing with Tokenvape e-liquids moving forward. Though I should say, within e-liquids there is no agreed 'safe limit' of a chemical to aim for. Testing for DA, AP or acetion is fine, so long as we all agree how much is or is not a safe amount within an e-liquid.
At the risk of repeating myself a little, shouldn't we also be proving that these chemicals in any amount are actually a health concern in the first place? Agreed guidelines and standards need to be set at all levels for any of this stuff to really matter.
We need scientific, peer reviewed, tangible links with evidence before lambasting Diacetyl or any
other chemical within the vaping world before we raise the pitchforks and start taking legal action against companies. We need to work together as a community or we will not survive the coming fight against big tobacco companies and big pharmaceutical companies this year and beyond.
Legislation is coming, its impact will be enormous upon the entire industry, worldwide. We can bicker and fight each other or we can take a stand now in solidarity as vapers. Handing the 'ill-informed opinion stick' to our enemies in which to beat us with is as illogical as it gets.
Matt from Suck My Mod did a great little video about this subject on his YouTube page recently which echoes much of the same concerns we have around this. I strongly urge others to go have a watch: