Recent studies indicate the substitutes being used have the same health dangers as diacetyl.
Link to abstract of late-2013 study:
Evaluation of the hypersensitivity potenti... [Food Chem Toxicol. 2013] - PubMed - NCBI
and the text:
Concern has been raised over the association of diacetyl with lung disease clinically resembling bronchiolitis obliterans in food manufacturing workers. This has resulted in the need for identification of alternative chemicals to be used in the manufacturing process. Structurally similar chemicals,
2,3-pentanedione, 2,3-hexanedione, 3,4-hexanedione and 2,3-heptanedione, used as constituents of synthetic flavoring agents have been suggested as potential alternatives for diacetyl, however, immunotoxicity data on these chemicals are limited. The present study evaluated the dermal irritation and sensitization potential of diacetyl alternatives using a murine model. None of the chemicals were identified as dermal irritants when tested at concentrations up to 50%. Similar to diacetyl (EC3=17.9%), concentration-dependent increases in lymphocyte proliferation were observed following exposure to all four chemicals, with calculated EC3 values of 15.4% (2,3-pentanedione), 18.2% (2,3-hexanedione), 15.5% (3,4-hexanedione) and 14.1% (2,3-heptanedione). No biologically significant elevations in local or total serum IgE were identified after exposure to 25-50% concentrations of these chemicals. These results demonstrate the potential for development of hypersensitivity responses to these proposed alternative butter flavorings and raise concern about the use of structurally similar replacement chemicals. Additionally, a contaminant with strong sensitization potential was found in varying concentrations in diacetyl obtained from different producers.
'Hadn't had any time to do any research and check this out until now...
>From here:
CDC - Flavorings-Related Lung Disease: Exposures to Flavoring Chemicals - NIOSH Workplace Safety and Health Topic
2,3-Pentanedione
The alpha-diketone, 2,3-pentanedione, has received attention as a flavoring substitute for diacetyl.
It is also known as acetyl propionyl or by CAS number 600-14-6. It is structurally very similar to diacetyl since 2,3-pentanedione is a 5-carbon alpha-diketone and diacetyl is a 4-carbon alpha-diketone. Published reports on the toxicity of 2,3-pentanedione were first published in abstract form in 2010 (Hubbset al. 2010b; Morgan et al. 2010). A recent NIOSH peer-reviewed publication documents that acute inhalation exposures to 2,3-pentanedione cause airway epithelial damage that is similar to diacetyl in laboratory studies (Hubbset al. 2012)....
>From here:
Popcorn flavoring effects on reac... [J Toxicol Environ Health A. 2013] - PubMed - NCBI
Data suggest that the effects of 2,3-pentanedione on airway reactivity are greater than those of diacetyl, and that flavorings are airway smooth muscle relaxants and constrictors, thus indicating a complex mechanism.
>From here:
https://www.osha.gov/SLTC/flavoringlung/diacetyl_worker_alert.html
Examples of Flavors That May Contain Diacetyl and Substitutes
Dairy flavors (e.g., butter, cheese, yogurt flavors).
"Brown" flavors (e.g., caramel, butterscotch, brown sugar).
Other flavors (e.g., butter pecan, some fruit flavors).
***
Diacetyl substitutes that have not been proven to be safe include diacetyl trimer, 2,3 hexanedione, 2,3 heptanedione, and 2,3 pentanedione.
So how much is too much? From here:
CDC - NIOSH Update - Diacetyl and 2,3-pentanedione: NIOSH Seeks Comment On Draft Criteria Document
For Diacetyl, a recommended exposure limit (REL) of 5 parts per billion (ppb) as an eight-hour, time-weighted average, (TWA) during a 40-hour work week. To further protect against effects of short-term exposures, NIOSH recommends in the draft document a short-term exposure limit (STEL) for diacetyl of 25 ppb for a 15-minute time period.
For 2,3-pentanedione, a recommended exposure limit (REL) of 9.3 parts per billion (ppb) as an eight-hour, time-weighted average, (TWA) during a 40-hour work week. The REL for 2,3-pentanedione in the draft document is based upon the lowest level at which the substance reliably can be detected using the existing analytical method, and should not be misconstrued to imply that 2,3-pentanedione is of lower toxicity than diacetyl. Further, NIOSH recommends a STEL of 31 ppb to limit peak exposures for 2,3-pentanedione on the same basis of analytic method limitation.
What "percentage" is "parts per billion"?
Parts Per Billion Conversion Chart (Fractions and Percent Converter, Percentages And Parts)
5 ppb = 0.0000005%
9 ppb = 0.0000009%
25 ppb = 0.0000025%
31 ppb = 0.0000031%
Yet the recently posted "good news" (???)
http://www.e-cigarette-forum.com/forum/diy-e-liquid/530906-good-news-coming-capellas-flavoring-direct-tom.html :
1). For those worried about whether or not Diacetyl is in their flavors, he said he would be more than happy to provide a signed statement confirming that Diacetyl is in fact not present in any of their flavors. They have done GC/MS testing on their flavors and can provide a report showcasing this on request for those concerned (similar to the one I posted for their Vanilla Custard). He said he was more than happy to do this as he understands the cause for concern.
2). Acetyl Proprionyl is in certain flavors, like the Vanilla Custard flavoring, but for those concerned, they are doing testing on % mixes at 5%, 10%, 15%, 20% and 30% to confirm the levels in the final product (i.e. meaning, a mixed e-liquid using PG and VG) and they plan on reporting said information. This means we'll be able to make a truly informed decision and we'll have a general idea of how much of the chemical will be present. I don't have a finite date on when it'll be done, but he said very soon - so I'd imagine a few months at most, a few weeks at the least. Since these flavors are used in other industries, they won't be removing it from the existing line, but.....
So the "good news" is...
...that they use Acetyl Proprionyl instead of diacetyl - but that ingredient isn't disclosed anywhere on sales sites (that we can find after doing domain searches)
...that the GC/MS that showed "less than .4% diacetyl" (upon which they base their claim for "diacetyl free"?) is the same test they'll be using for the Acetyl Proprionyl (when we need testing that can reveal parts per billion)? EDIT - oops, I see that Capella is going to test for parts per billion. END EDIT
...people continue to defend vendors & manufacturers who continue to add, create, and profit from selling these known harmful chemicals (UNDISCLOSED) to flavors they sell.
We see acetyl propionyl is "2,3 pentanedione" (which appears to be as dangerous as diacetyl)...but what the heck are the others? (
Structurally similar chemicals, 2,3-pentanedione, 2,3-hexanedione, 3,4-hexanedione and 2,3-heptanedione). And are we sucking them into our lungs when vaping diacetyl-free, acetoin-free, acetyl propionyl-free flavors? And why aren't we all concerned - and doing our best to find out, research & share? We certainly have no problem with discussing the health-damaging chemicals in cigarettes (and bashing the companies that add them).
Certainly we can't be silly enough to think that when going from inhaling scorching smoke, tar, and the chemicals in cigarettes, that we'd be able to discern the harm being done when inhaling a 'cooler-softer vapor' that reduces the symptoms from the scorching smoke & tar. And double-certainly, we cannot rely upon chemicals that've been 'certified' as GRAS by the 'authority agency gods' even being safe to ingest...let alone be mainlined into our bloodstream via inhalation.
It's definitely
not "anti vaping" to want to vape in the safest way possible! And after going from one or two brands (flavors) of cigarettes, it's not like it would be some kind of 'major sacrifice' to eliminate the chemicals/flavors that are damaging. Good heavens, we'd only have hundreds/thousands of options for flavors leftover!
I like the way "mrwizard" put it here:
Which One Is Right/Wrong?? Acetoin/Diacetyl
As Linda states on the TPA link you have, it's possible for Acetoin to create trace amounts of Diacetyl.
One research paper I read on analysing Acetoin and Diacetyl in bacterial cultures mentioned that the researchers converted Acetoin into Diacetyl by a simple oxidation process involving ferric (iron) chloride.
Bottomline is this means that even though a flavoring company does not use Diacetyl directly, it's still possible for their flavoring to end up containing Diacetyl if they use Acetoin.
Is that trace amount going to be enough to create a health hazard or increase your risk of developing bronchiolitis obliterans (popcorn lung) in the average vaper?
Is the amount of Diacetyl absorbed when vaping Custard flavors still made with Diacetyl enough to reach that threshold of increased risk?
Are Acetoin or Acetyl propionyl themselves going to be found to be as much of a health risk as Diacetyl?
We can't know for sure as OSHA is still gathering the data to determine that, but they are concerned enough that they've already told us they ARE going to be changing the workplace regs regarding exposure.
What I do know is we have a very large, real-world experiment going on involving vaping guinea pigs, and I'm betting in the next decade or two we'll have those answers.
Personally, I'm vaping to get away from known health hazards, and since I have literally millions of flavor combinations to choose from that don't contain Diacetyl or Diacetyl-related compounds, I've got no desire or need to be a guinea pig for this particular experiment.
Wethinks it's essential to learn & share as much knowledge as possible. Parts. Per. BILLION.
.
