New studies find carcinogens in vg and pg at high temps, even in tootle puffers

[DaveP]

Responsible use of e-cigarettes constitutes a much safer alternative to smoking, IMO. Even cloud attys can be safe as long as the airflow is high enough to keep the vapor cool.

I'm confident, especially with MikePetro's tests, that vaping is safe at my 10W level in a Kayfun. I get a vapor stream that's parallel to the smoke from my old ultra light tobacco cigarettes, but without the tar and nasty chemicals that were in cigarette smoke. I've had several X-rays and a CT scan that showed clear lungs without the slight haze that cigarettes create from residual tars. My lungs look good these days after 8+ years of vaping and NO smoking.

I think I can say that vaping has extended my life over the path that I was on with cigarettes. ANTZ can concoct all the skewed data they want to, but my personal results show that I'm a healthier guy after 8 years of vaping and no smoking. My doctor agrees.

 

[mikepetro]

Looks like BP is fighting back.

"The incidence of major cardiovascular events was low over a year of follow-up in users of varenicline (Chantix), bupropion hydrochloride (Zyban), nicotine-replacement therapy (NRT), and placebo, and adverse events did not differ by treatment.

There was also no evidence of an effect of any active drug versus placebo on time to cardiovascular event, blood pressure, or heart rate over 12 weeks of treatment, 30 days post-treatment, and up to 52 weeks of follow-up."

"The study was funded by Pfizer, which markets Chantix, and GlaxoSmithKline, which markets Zyban and the NRTs Nicorette and NicoDermCQ."

Study: No Heart Risk with Smoking-Cessation Meds

I think the Big-X players are starting to get their ducks in a row to fill the big vacuum that reduced nic cigarettes will create.

But now they are after our caffeine.
FDA Warns on Bulk Caffeine

Watch what they do with caffeine, they will treat nic even harsher.

 

[DaveP]

Looks like BP is fighting back.

"The incidence of major cardiovascular events was low over a year of follow-up in users of varenicline (Chantix), bupropion hydrochloride (Zyban), nicotine-replacement therapy (NRT), and placebo, and adverse events did not differ by treatment.

There was also no evidence of an effect of any active drug versus placebo on time to cardiovascular event, blood pressure, or heart rate over 12 weeks of treatment, 30 days post-treatment, and up to 52 weeks of follow-up."

"The study was funded by Pfizer, which markets Chantix, and GlaxoSmithKline, which markets Zyban and the NRTs Nicorette and NicoDermCQ."

Study: No Heart Risk with Smoking-Cessation Meds

I think the Big-X players are starting to get their ducks in a row to fill the big vacuum that reduced nic cigarettes will create.

But now they are after our caffeine.
FDA Warns on Bulk Caffeine

Watch what they do with caffeine, they will treat nic even harsher.

Funny that they didn't include electronic cigarettes in that article. They are obviously touting their own industry's products.

 

[ScottP]

Funny that they didn't include electronic cigarettes in that article. They are obviously touting their own industry's products.

Of course. You can't expect them to be completely honest.

 

[Rossum]

But now they are after our caffeine.
FDA Warns on Bulk Caffeine

Watch what they do with caffeine, they will treat nic even harsher.

Yep, the way they're justifying this does not bode well.
FDA Bans Pure and Highly Concentrated Caffeine

 

[DaveP]

Everyone's happy with Starbucks ... Have a cup and an intense sugar shot on your way to work. Except California, who says it's a carcinogen.

In California Coffee May Soon Be Listed As A Carcinogen

World Health Organization (WHO) is out to get your air.
World Health Organization: Outdoor Air Pollution Causes Cancer

I'm not particularly worried about 10W vape dangers.

 

[ScottP]

Everyone's happy with Starbucks ... Have a cup and an intense sugar shot on your way to work. Except California, who says it's a carcinogen.

In California Coffee May Soon Be Listed As A Carcinogen

Wow California is scared of everything. "The sky is falling".

World Health Organization (WHO) is out to get your air.
World Health Organization: Outdoor Air Pollution Causes Cancer

I'm not particularly worried about 10W vape dangers.

Breaking news: no matter what you do, you will, at some point, die.

 

[untar]

no matter what you do, you will, at some point, die.

You better not die from cancer though or they'll have your body put in a salt mine for final storage.

 

[mikepetro]

Interesting reading. Confirms what I felt like I was observing myself.
Also accounts for why that last 20% of a tank of 50/50 PG/VG gets so thick, it is mostly VG by that point.


4.1 Aerosol composition
A key observation in this regard was the fact that for a given liquid, electrical power affected
not only the amount of aerosol emitted, but also its composition. In particular, as shown in
Figure 6, at low power the aerosol produced by a 50/50 PG/VG liquid solution is composed
almost entirely of PG, the more volatile component of the solution. This result is consistent
with evaporative partitioning theory for ideal solutions (i.e. Raoult’s Law), which states that
the evaporation rate of each species is proportional to the product of its intrinsic vapor
pressure and its mole fraction in the liquid phase. Because the vapor pressure of PG is much
greater than that of VG, vapors evaporating from a 50/50 PG/VG solution must be composed
mainly of PG. However, as power was increased, Figure 6 shows that the composition
shifted towards that of the parent liquid, i.e., towards a 50/50 PG/VG composition.
Application of Raoult’s law shows that a liquid composed of 7/93 PG/VG is required to
produce an aerosol of 50/50 PG/VG composition. In other words, at the higher power
conditions, the local liquid composition in vicinity of the coil must differ greatly from the
50/50 PG/VG parent liquid found in the tank reservoir. These observations point to the
conclusion that resistance to species transport by diffusion within the wick gives rise to a
concentration gradient between the tank and heated zone. As a result, accurate prediction of
nicotine flux over a range of ECIG operating conditions requires a model that allows the
composition of the liquid near the heating coil to vary in time, even if the parent liquid
composition in the tank remains unchanged.

The above dynamics are observable in the model simulation of a single puff at low and high
power, shown in Figure 8. For both conditions, at the start of the puff the mass fractions of
liquid PG and VG (Figure 8b) correspond to those of a 50/50 PG/VG liquid (by volume).
Once the puff starts, the temperature of the heated zone begins to rise (Figure 8a), and
evaporation commences. During the early phase of the puff the more volatile PG is driven
off the liquid at a far higher rate than is the less volatile VG (Figure 8c), and as a result the
vapors are almost exclusively composed of PG (Figure 8b). As the puff proceeds, the
temperature continues to rise, causing the vaporization rate to accelerate (Figure 8c), and the
liquid composition in the wick to shift towards VG. Eventually, this shift is sufficient to
increase the VG presence in the vapors as well. This shift occurs far more rapidly in the high
power condition, resulting in a vapor composition that more rapidly approaches that of the
parent liquid

(While they are using POWER as the variable, I would be willing to wager that the true Metric is temperature.)

(15) Transport phenomena governing nicotine emissions from electronic cigarettes: Model formulation and experimental investigation. Available from: Transport phenomena governing nicotine... (PDF Download Available) [accessed Apr 20 2018].

 

[untar]

I assume there's next to zero people actually vaping at what they classify as "low power". While interesting it tells us little about real world vaping. As you said a temperature reading would have been much more useful.

 

[mikepetro]

I think it does confirm that in a mixture, PG will vaporize long before the VG does. Which makes sense based on boiling points etc.

Juice Boiling Point and Vaping Temperatures (includes BP Charts)

 

[Rossum]

Also accounts for why that last 20% of a tank of 50/50 PG/VG gets so thick, it is mostly VG by that point.

Yet another reason to use a squonker rather that a tank!

 

[untar]

it does confirm that in a mixture, PG will vaporize long before the VG does

Yes it does that, but who vapes at those power levels? I'd say below 7-8W you'd be hard pressed to find anyone. With the right wire I think I'd be able to exceed 300°C with only 3-4W anyways so just the power seems quite a weak analysis (like you already pointed out).
The ex-chairperson of the German cancer research center wanted to limit all vapes to 2W (and thankfully failed)

I'm fairly confident most people vape around 180-240°C so an analysis of that range with different juice compositions would be much more interesting to us.

A cherry on top would be an analysis of flavor compound profiles over a temperature curve but that'd be an enormous undertaking so not expecting that in the near future.

 

[mikepetro]

I am just dumbfounded.

How is it that all of these truly brilliant scientist dont see that power is only a process variable, and that temperature is the actual catalyst.

 

[untar]

How is it that all of these truly brilliant scientist dont see that power is only a process variable, and that temperature is the actual catalyst.

I think they don't know about TC mods and try to relate their findings to power settings. At least every single Chemist on earth knows they care more about the actual temperature set than any momentary power their magnet stirremathing puts out to maintain it.

Or this may be a very subtle hint at power setting regulation

 

[CMD-Ky]

Which is why I think of vaping as a method of "risk reduction" rather than harm reduction. What ever the risks of vaping may be it appears that the risk with vaping may approach a 75% reduction.

So you're telling us that even at 500°F, with the worst possible liquid (100%VG), we're at less than 1/4 the level of tobacco....?!?

Oh, and didn't you previously tell us that at around 510°F, it started tasting bad?

I have only one thing to say:

 

[mikepetro]

Which is why I think of vaping as a method of "risk reduction" rather than harm reduction. What ever the risks of vaping may be it appears that the risk with vaping may approach a 75% reduction.

Or more unless you on the extreme edge of high temp and/or volume.

 

[Cas002]

This research is very significant IMO. The dynamics of vaping are highly complex and they not only investigated the transport phenomena but also created a strong framework for other researchers to follow. I know it's not perfect, and Temperature should have been a variable, but I'm sure researchers will expand on this work. A few weeks ago I dusted off my Heat Transfer textbook from 30+ years ago to research the impact of forced convection on coil temperatures (using a cylinder model) to validate my theory that DTL and MTL draws impact coil temps measurably different (DTL having greater air volume per draw reduces temps more) but I struggled with some of the assumptions around the airflow of DTL vs. MTL and never completed a quick 'n dirty calculation...I'll get back to it soon. They cover forced convection and many other factors in the complex vaping system. I'm just starting to read the PDF of this research and really looking forward to it. Great find @mikepetro, thanks!

 

[CMD-Ky]

Or more unless you on the extreme edge of high temp and/or volume.

I am on the extreme edge of many things but temp is not one of them, 410 or lower on TC (Evolve board, supposedly fairly accurate). Nine Watts, around seven Ohms on power. I don't understand the "volume", what does that refer to?

 

[Rossum]

Which is why I think of vaping as a method of "risk reduction" rather than harm reduction. What ever the risks of vaping may be it appears that the risk with vaping may approach a 75% reduction.

I figure the overall risk reduction is much greater. Even if the average non-TC vaper is getting 25% of the carbonyls that a smoker does, he's still not getting all the other crap; the tar, the carbon monoxide, the TSNAs, etc, etc, etc.