Dr Farsolino - diacetyl and acetyl propionyl in e-liquids study report

NIOSH submits letter to the editor concerning our diacetyl study


By Dr Farsalinos

The National Institute of Occupational Safety and Health (NIOSH) submitted a letter to the editor of Nicotine and Tobacco Research journal concerning our diacetyl-acetyl propionyl study. As you may remember, that was a chemical analysis study evaluating 159 e-liquids from Europe and the US for the presence of diacetyl and acetyl propionyl. We found that 74.2% of the samples were positive for the presence of these chemicals. To assess the level of exposure, we used the NIOSH-established safety limits of occupational exposure and determined that the average daily exposure from the liquids tested was 100 and 10 times lower than NIOSH-set limits. The letter and our response were published by the journal today, but since they are not open-access, I will present the main points of the NIOSH letter and our response herein.

The main purpose of the NIOSH letter was to clarify that the limits set by the institute refer to occupational exposure and not to consumers or the general public and that the comparison between smokers (or vapers) and occupational exposure is not widely accepted. The authors of the letter supported that their Occupational Exposure Limits are not applicable to sensitive population subgroups but to people healthy enough to work. They added that the NIOSH-established safety limit is not a measure of absolute safety but a level of exposure that would result in less than 1 in 1000 workers developing lung dysfunction after 45 years of exposure. Moreover, they expressed concern about the accuracy of the cigarette smoke content of diacetyl as measured by Pierce et al, implying that the levels in smoke are lower than what they measured. However, they provide no justification for this. Finally, they mentioned that in our calculations we underestimated the breathing volume of workers by considering that they have a basic resting ventilation rate. They argued that workers conduct manual activity during their working hours, resulting in significant elevation on breathing rate and volume.

In our response, we used the NIOSH arguments to further support the appropriateness of our approach. In particular, we mentioned that the targeted population for e-cigarette use is the smoking population. Whether sensitive or not, these people are exposed to a large number of toxicants on a daily basis for many years. Additionally, we emphasized that a risk level of 1 in 1000 developing lung dysfunction represents a tremendous benefit for smokers who have a 1 in 3-4 risk of developing chronic obstructive lung disease in their lifetime. Additionally, we provided further evidence from the literature on the levels of diacetyl in tobacco cigarette smoke. Studies by Fujioka and Shibamoto and by Moree-Testa and Saint-Jalm found diacetyl in smoke at levels similar to the study by Pierce et al. Finally, we accepted the argument by NIOSH that we underestimated the ventilation rate of workers. That was a conscious decision, because we wanted to use the most stringent criteria in the comparison. Thus, we used the worst-case scenario of resting ventilation rate, which underestimated the safety-limit exposure set by NIOSH. Based on mild and moderate activity, the NIOSH-estimated safety exposure limit would be 86micrograms/day (mild activity) and 302micrograms/day (moderate activity) for diacetyl, and 132micrograms/day (mild activity) and 638micrograms/day (moderate activity) for acetyl propionyl. Our initial calculations considering resting ventilation rate was 65micrograms/day for diacetyl and 137micrograms/day for acetyl propionyl. Thus, the NIOSH-set limits are approximately 50-400% higher than what we considered in our original study, using the worst case scenario.

In conclusion, it is important to provide a comparative measure of exposure to diacetyl and acetyl propionyl from e-cigarette use, considering that the targeted population is smokers who have a high risk of developing disease and are continuously exposed to several toxins (including diacetyl and acetyl propionyl). In any case, we made clear that diacetyl and acetyl propionyl represent an avoidable risk and every effort should be made to remove them from e-liquids. In our opinion, the major impact of our study is that it alerted the industry to take care of this issue. Anecdotal evidence suggests that there is a lot of improvement in this area, and we believe that a future study is needed to evaluate and verify whether diacetyl and acetyl propionyl have been removed from e-liquids.

 

Thanks for sharing BuzzSamui. I am very happy that Dr. Farsalinos already notice that there are liquid makers who already are trying to remove the 2 chemicals, and I also noticed that some e-liquid shops have stop selling liquid with these to components. Good if the vaping community and the makers can manage this without the need of governmental control.

 

Some makers will report how much they have in them but refuse to remove it. Some of the new flavours im working on are not easy because of this, and I have to find work arounds. Everything I supply is diacetyl and acetyl propionyl free, but you cant be sure if there other things that could be found harmful in the future. As these are removed from flavours they are replaced and the replacemnets have not had vaping studys done on them. Unfortunatly this is something we will have to live with for a long time and will evolve as does vaping. Hopefully in a positive and heathier way. One thing is sure, vapings better than smoking.

 

I totally agree on this. But it is a lot better that the community together with the producers address this than risking governmental restrictions.

 

Government restrictions? can't hear this anymore because other than tax and a few others which are implemented on Vaping as well what restrictions does tobacco has. Just lock at us, tobacco is easier to get than e-liquid. The world knows how much impact tobacco has to a human for quite a wile now but has tobacco be band in any country in the world yet? No! and thats for several good reasons.If it's about health concerns, well than i recommend anybody not to visit any big city in the world just to stay away from toxins and if we are that far already, make sure you never eat cooked or processed food with food flavoring.
How many times have you read an article about smoking tobacco in which were about 4 more potential dangerous chemicals found in a recent study and no one gave a f... because everyone already knows how dangerous tobacco smoking is? Ok, so whats the problem, tell everyone Vaping is not much better than smoking, let the government tax the sales and bring in the gear for us to buy with our own choices of what is best for us. I would pay 10$ more on gear if i could choose from a variety of gear in a shop were i can see and try stuff, no problem at all. Juice, well go ahead and tax it because you are able to DIY which might be a better option anyhow if you don't want to pay for hype and packaging.

What it comes down to is, i rather Vape than smoke tobacco at the moment and we all know i am not alone and becoming more and more company and that is the real problem for some institutions and what is even scarier is that the masses either don't care about Vaping or support it.