Tag Archives: toxins

Burstyn comments at FDA workshop on ecig science

by Igor Burstyn

[Editor’s Note: As I mentioned previously, FDA refused CASAA’s application to have Igor appear on the agenda of the FDA workshop on e-cigarette chemistry and related science. After seeing who they did put on stage, it became doubly clear that they were intentionally avoiding Igor because he had the expertise and credibility to point out fundamental flaws in a solid majority of what was presented. Fortunately Greg Conley had three minutes on the agenda and gave it to Igor, so that he could present the following talk. It was not a lot of time, but it was enough for Igor to point out how absurd is most of what passes for science in this realm. His slides are here. I have inserted the slide advance marks in the text. –CVP]

[Slide 1] Good morning, folks. First, a small correction. Actually, my affiliations are on the slide now, not from the previous introduction.

[Slide 2] So what I’d like to talk to you about today very briefly is that there’s really not that much new under the Sun about e-cigarettes. I don’t come from the tobacco control world. I come from a very different area of academia and research. And I was surprised that so many things about electronic cigarettes were surprising to people. So that’s my story.

So we’re really not all that ignorant about toxicology of what comes out of electronic cigarettes. And I talk about it as somebody who’s trained in industrial hygiene, environmental health, who was taught to anticipate what would happen if my workplace had a source of environmental emission introduced to it that was very much like electronic cigarettes, and it was there, and it was exposing me. And I was trained through my undergraduate and my graduate training to recognize and deal with those situations and be able to make rational decisions about mitigating risks for myself, and my co-workers and my colleagues.

We have rich experimental experience from other areas of environmental and workplace emission controls and hazard assessments that are incredibly helpful and can be easily applied, and are portable to the world of electronic cigarettes and tobacco products. And there’s really no reason to assume this precautionary posture that really amounts to willful ignorance. We really know a lot more than we sometimes give ourselves credit for. And my claim to credibility, such as it is, is summarized in this paper, and if you’re really interested in what I have to say on this topic, it’s all published out there. You’re most welcome to contact me. I’m easily found.

[Slide 3] But this is my main point, which was made yesterday as well: The dose makes the poison. We have known that for a very, very long time, and it’s really not helpful for us to think otherwise because nothing really has changed in the truth of that statement since Paracelsus put it forward. And this is part of the story. [Slide 4] If we apply the standards that are admissible in workplaces to emissions from electronic cigarettes and look at about nine thousand chemical measurements that were available to me back last summer, we can see that across chemicals, we see individual exposures that are way below a threshold where we’d actually begin to worry about them. There’s really no reason to be concerned here. Most of them are in trace quantities. They’re present, but they’re not going to hurt you.

[Slide 5] And if you look at similar calculations based on emissions from vapers, you can reach the same conclusion. You can sit or stand near a vaper and experience emissions they generate, and you should not be worried or afraid for your life or health.

[Slide 6] So we do know a good deal about electronic cigarettes. If the word “cigarettes” was not in that title, we wouldn’t really be that worried about them because it’s just a name. And it’s not really appropriate to deal with these things as if we learned nothing since the 16th century. Scientists don’t try to avoid vials of chemicals; likewise, public should understand and treat chemicals with respect, but we should not be afraid of them.

Thank you very much for your attention.

[Slide 7 contains further observations that could not be fit in the limited time.]


The passive vaping fable

posted by Elaine Keller (with input from Carl V Phillips)

Mr. Smith was delivering a speech across town in front of 800 people when the murder occurred. He had no blood on his clothing. Police could find no trace evidence at the scene that leads to Mr. Smith, and were unable to come up with a motive for the crime. Mr. Smith is a prime suspect.

The last sentence is a confounding conclusion. Not confounding in the epidemiologic sense – I will leave that topic to Carl – but in the sense of being baffling. It causes surprise or confusion because it acts against the reader’s expectations. When such conclusions appear in a murder mystery or puzzler, they can be entertaining. When they appear in scientific journal articles, they are perplexing. Or, in the spirit of this blog, they are lies.

Take the case of the paper published by German researchers on the subject of chemicals in electronic cigarette (e-cigarette) vapor.

Schripp T, Markewitz D, Uhde E, Salthammer T. Does e-cigarette consumption cause passive vaping? Indoor Air. 2012 Jun 2.

The final paragraph of the Conclusions section states,

“Overall, the e-cigarette is a new source of VOCs and ultra-fine/fine particles in the indoor environment. Therefore, the question of “passive vaping” can be answered in the affirmative. However, with regard to a health related evaluation of e-cigarette consumption, the impact of vapor inhalation into the human lung should be of primary concern.”

The reader is left with the impression that Schripp et al. found chemicals in e-cigarette vapor that would definitely endanger the health of users. The most likely way readers will interpret the phrase “passive vaping” is that the researchers found chemicals in the exhaled vapor that would be hazardous to the health of bystanders as well, given the fact that the CDC attributes 49,000 deaths each year to “passive smoking.”

The first rule of toxicology is “the dose makes the poison.” This means that it is important to know not only what chemicals are involved, but also the quantity of chemicals that are present. Almost any substance (even water) is toxic in large enough quantities and many “toxic” chemicals are harmless, or even helpful in some cases, in smaller quantities.

Fluoride is a good example of the first rule of toxicology. In concentrations of less than 0.5 percent in toothpaste, stannous fluoride and sodium fluoride helps strengthen teeth and prevent cavities. However, toothpaste overdose may cause stomach pain and possible intestinal blockage.

So what experiments did Schripp and his colleagues perform? There were two parts. The “large scale vaping/smoking experiment” was performed in an 8 cubic meter stainless-steel emission test chamber (about the size of the interior of American family SUV or minivan – with the windows up and the vents closed). A volunteer sat in the chamber and air quality was sampled after 20 minutes to establish a baseline. Then the volunteer was given an e-cigarette with one of three liquids: apple-flavored with no nicotine; apple-flavored with a nicotine concentration of 1.8%; and tobacco flavored with 1.8% nicotine. This was followed by a last trial, in which the volunteer smoked a cigarette.

For the large scale stainless steel chamber experiment, the researchers reported on the 20 compounds with the highest concentrations, comparing them to the concentrations at baseline. Fourteen of the 20 compounds that increased for the cigarette smoke showed no increase over baseline for the vapor of any of the three e-cigarette samples. The six compounds that did increase for vapor samples were 2-butanone (MEK), acetic acid, acetone, isoprene, formaldehyde, and acetaldehyde.

In their conclusions, the researchers failed to point out that many more compounds were found in smoke than in vapor, and they did not compare the quantities of compounds measured in vapor to those measured in smoke. The quantities measured in vapor ranged from 1/10th to 1/40th those generated by cigarette smoke.

Just how hazardous are the compounds in vapor? The Occupational Safety and Health Administration publishes permissible exposure limits (PELs) for hundreds of chemicals that might be present in the air at workplaces. Five of the six compounds were present in quantities that are less than 1% of the PEL. The sixth compound, formaldehyde, is produced naturally by the human body, and it was present at 2.4% of the PEL. If the researchers had provided this comparison in their data, it would have been obvious that their conclusions did not fit the facts.

Apparently the researchers were surprised at what they did not find. “Although 1,2-propanediol [propylene glycol] was detected in traces only within the 8 m³ chamber during the consumption of e-cigarettes, this compound must be released due to the visible fume in the exhaled breath. To determine the VOC composition in the breath gas directly, an e-cigarette smoker exhaled into a 10 L glass chamber.”  (Interestingly, this could be interpreted as them saying, “we changed our methodology on the fly because we did not like the results we were getting.”)

Perhaps they also were surprised that nicotine did not show up in their list of the 20 compounds with the highest concentration in smoke. Analysis of the immediately captured breath in the glass chamber resulted in a different list of chemicals than the stainless steel chamber experiment. The abstract states, “Prominent components in the gas phase are 1,2-propanediol, 1,2,3-propanetriol, diacetine, flavourings and traces of nicotine. As a consequence, ‘passive vaping’ must be expected from the consumption of e-cigarettes.”

The sequence of these sentences would lead the reader to believe that the chemicals specified in the first sentence lead to a condition they call “passive vaping” implying that it is similar in risk to “passive smoking.”

The extremely low quantities in the stainless-steel chamber experiment indicate that most of the chemicals found in concentrated captured exhalation disappear in the ambient air. For example, although nicotine was present (at 1.4% of the exposure limit) in the glass chamber experiment, no nicotine at all was detected in the stainless-steel chamber experiment. A bystander would need to lock lips with an exhaling e-cigarette user to be exposed to all the “prominent components of the gas phase” measured in the glass container experiment.

Even with the lip-lock, the highest level of chemical exposure in the second experiment (glycerin) is only 9.5% of the PEL. Two of the chemicals are not considered harmful at all. Not surprisingly, the highest concentration was for 1,2-propanediol, aka the non-toxic carrier, propylene glycol. If passive vaping is supposed to mean that bystanders are exposed to harmful levels of chemicals, then neither experiment in the study proved the existence of passive vaping.

Nothing in the perplexing conclusion to this article informs the reader about the extremely low level of danger represented by the quantities of chemicals detected. An accurate conclusion might have stated, “The consumption of e-cigarettes causes emissions of aerosols and VOCs, such as 1,2-propanediol, flavoring substances and nicotine, into indoor air; however the quantities of these substances are so low that they do not present a health hazard to bystanders or to the users themselves.”