Effect of variable power levels on the yield of total aerosol mass and formation of aldehydes in e-

[Kurt]

Thanks i saw the description for the gladius coils, but didn't notice in your paper if the pt coils were silica or cotton. Kanger makes cotton coils for pt as well, that is why i asked.

At the time the data was being collected, PT cotton coils were not widely available yet. We were aware of them while the paper was under review. I personally have tried them very recently (a variety of ohms), but for my VG liquids they don't do a lot better than silica single coils in my own vaping experience. YMMV. I gather some really love them, but they may work better with a PG/VG mix. Most attys do. Have not measured emissions with them.

 

[zoiDman]

We wanted to use stock devices, un-modded. Otherwise too many variables, and not what the majority of vapers will do anyway.

I've tried a CE6 with my DIYs, but it didn't do much better than a CE4. I never had good consistent results with a Protank single coil (2.5 ohm was barely tolerable).

You really Had to use Unaltered Devices. Else you would go down the Rabbit Hole of what Modding was to be Done. And as you mentioned, the Majority of Vapers are using Out-of-the-Box Devices in this class of Atomizers.

The Big Takeaway from all this should be that Efficient Wicking and Adequate Air Flow is in Direct Proportion when it comes Potential for Toxins due to Thermal Breakdown of e-Liquids being seen in e-Cigarette Vaper.

 

[Mazinny]

At the time the data was being collected, PT cotton coils were not widely available yet. We were aware of them while the paper was under review. I personally have tried them very recently (a variety of ohms), but for my VG liquids they don't do a lot better than silica single coils in my own vaping experience. YMMV. I gather some really love them, but they may work better with a PG/VG mix. Most attys do. Have not measured emissions with them.

Yes, i suspect they would work a lot better with the liquids i use ( 50/50 for the most part ) than your liquids. I also mod the factory coils and use a better air flow base than the standard pt2 base.

 

[Kurt]

Another thing people need to be aware of is that we did not use any flavors, which could also decompose on the coil, to a lot more than just these aldehydes. That a whole other can of worms, and a very big one at that. But I want to emphasize that in general it is probably still less toxic emissions than cigarettes.

You really Had to use Unaltered Devices. Else you would go down the Rabbit Hole of what Modding was to be Done. And as you mentioned, the Majority of Vapers are using Out-of-the-Box Devices in this class of Atomizers.

The Big Takeaway from all this should be that Efficient Wicking and Adequate Air Flow is in Direct Proportion when it comes Potential for Toxins due to Thermal Breakdown of e-Liquids being seen in e-Cigarette Vaper.

I would agree with this last statement, but we did not look at variations on airflow where it was possible. If one could adjust air-flow, it was fully open. But yes, good air-flow will cool the coil down a lot.

 

[Kurt]

Yes, i suspect they would work a lot better with the liquids i use ( 50/50 for the most part ) than your liquids. I also mod the factory coils and use a better air flow base than the standard pt2 base.

I just started using the adjustable air-flow bases for PTs, and I like them. That on a PTIII and dual coil, and I am suddenly enjoying the protank again. I have also recoiled PT coils and gotten marginally good results with 32 ga and cotton. But these are mods, and not applicable to the study.

 

[Mazinny]

I just started using the adjustable air-flow bases for PTs, and I like them. That on a PTIII and dual coil, and I am suddenly enjoying the protank again. I have also recoiled PT coils and gotten marginally good results with 32 ga and cotton. But these are mods, and not applicable to the study.

I recoil using 29 gauge and aim for 1.8 ohms, use the aerotank afc v2, wide open setting. I get excellent results up to 11 or 12 watts up to 70 vg, although i use mostly 50/50 liquid. What i like about my set-up compared to the newer sub-ohm ones is the draw.

 

[Katya]

Fascinating study and very informative discussion. I have used all the devices used in the study (or similar) and had the worst luck with cartomizers, all the CE-type atomizers and ProTank 1-type BSC and BDC toppers (no airflow control).

@Kurt: Do you think that the high resistance wire used in stock HR coils (2.5-3Ω) combined with inadequate airflow (lack of AFC) is the culprit here? All those early coils are made of 32-34g wire (my estimate) that overheats very quickly indeed, especially when vapers take longer draws to get more vapor out of each puff. I always felt that the combination of very high resistance wires, poor airflow and inefficient wicking (due to small coil diameters) was a bad combination.

Anecdotal, but from my own experience, I can say with certainty that switching to higher resistance wire (29-28g), larger coil ID (2.5mm or so) and atties with airflow control, my vaping has become much more pleasurable. I haven't had a dry hit in years, no wicking problems, no issues with any kind of dry taste like I used to experience in the early days with cartomizers and then CE-type devices. I don't sub-ohm (vape at high wattages) at all and I'm an MTL vaper. Any thoughts?

 

[Katya]

We did not think pushing devices 1-4 to 25W was appropriate, but we could have used the DNA-40 for all devices. What wattages do you think would have been appropriate, and for which devices?

Don't remember what wattage I used with top-coil CE atties--I never liked them and stopped using them a long time ago. Wrt to devices 2-4, I liked most of those stock coils at 5-6 watts (per coil) with horizontal coils, roughly; a bit more with vertical builds.

 

[skoony]

In the meanwhile, do you suppose there is a chance that the wicking material might influence aldehyde production ? I ask because i believe there was a study earlier using cigalikes that didn't emit aldehydes in comparable amounts amounts to CE4's.

When i first started vaping it was with V2's a well known cigalike.Being a curious sort it wasn't long
before I was on the net googling this and that to find out what other brands were out here.
I found very many different cigalike vendors on the net back in 2013. I perused a lot of vendor
sites and read up on everything I could. I payed particular attention when it was mentioned
how does your e-cigarette work. It's a mater of proper wicking,viscosity and coil temperature.
The key is water. Added water in the right amount gives a desired viscosity between different
batches of PG.(not much talk of vg back then) Its gives the juice the ability to produce as intended
even in very arid conditions. It is also what made cigalikes work. With a set resistance in the coil
and, limited battery capacity there was simply no way to aerosolized the base mix any other way.
Sonic vibraters were in use in prototypes but were quite expensive.
In the transitional phase from liquid to gas water starts visibly evaporating at about 184 degrees F
before boiling. Optimum evaporation occurs at about 196 degrees F. That's why coils in
cigalikes rarely get above about 230 degrees F. You don't have to boil the water, just excite
it enough to reach optimum pre boiling evaporation to atomize the base and,your lungs do the rest.
During this time ego style devices were being introduced and a lot of experimenting was going
on. Ego styles had a little more power and juice capacity but still were based on the same principal.
On the other hand experimenters and vendors figured out if you drop the resistance of the coil
amperage increases and with that the heat flux of the coil which speeds up vapor production.
( this pre VV or VW or the very beginning of these types)
You still want to maintain about 196 degrees F but you want it accelerated to produce more
vapor quicker. And this is where proper wicking comes in. The wicking has to be able to maintain
enough flow to keep the process going. When there is not enough water to properly atomize the
base it will start heating as it is not being dispersed away form the coil quickly or efficiently enough.This is when dry hits and or overheated vapor heads south very fast.
Today the basics a still the same. Compare the size of a coil from your standard cloud
mod to one out of a Greensmoke cartridge. Bigger is better (maybe) but there are still
limits. Proper flow to the coil is the key. The trouble is there are so many different
types of atomizers,tanks,coils and power settings it confounds the results in many
cases to those that one expects.
I have read many times on this forum the complaints from those using sub ohm mods,
soaking the wick with straight vg and getting dry hits. There is a reason for that.
you do not want to heat VG to the transitional phase before boiling,let alone actually
boil it.

Regards
Mike

 

[Kent C]

But I want to emphasize that in general it is probably still less toxic emissions than cigarettes.

Probably?? There are several studies that make the case that ecig emissions are safer or as safe as air. And while I may give you the Dr. F data on certain flavors, (although I think Pierce's data is even better wrt B.O.), Dr. F purposely (and with transparency) cherry picked sweet flavors for that study, not all flavors have those attributes.

New Study Claims E-Cigarette Vapor No More Dangerous Than Air
Study Shows E-Cig Vapor Has Similar Level Of Risk As Air.

 

[Kurt]

Fascinating study and very informative discussion. I have used all the devices used in the study (or similar) and had the worst luck with cartomizers, all the CE-type atomizers and ProTank 1-type BSC and BDC toppers (no airflow control).

@Kurt: Do you think that the high resistance wire used in stock HR coils (2.5-3Ω) combined with inadequate airflow (lack of AFC) is the culprit here? All those early coils are made of 32-34g wire (my estimate) that overheats very quickly indeed, especially when vapers take longer draws to get more vapor out of each puff. I always felt that the combination of very high resistance wires, poor airflow and inefficient wicking (due to small coil diameters) was a bad combination.

Anecdotal, but from my own experience, I can say with certainty that switching to higher resistance wire (29-28g), larger coil ID (2.5mm or so) and atties with airflow control, my vaping has become much more pleasurable. I haven't had a dry hit in years, no wicking problems, no issues with any kind of dry taste like I used to experience in the early days with cartomizers and then CE-type devices. I don't sub-ohm (vape at high wattages) at all and I'm an MTL vaper. Any thoughts?

Maybe, but not sure. PT originals have such small tight coils, hard to say. But there could be something to your logic. I used to think it was also the silica, but cotton single coils are not much better for my liquids.

 

[Kurt]

Probably?? There are several studies that make the case that ecig emissions are safer or as safe as air. And while I may give you the Dr. F data on certain flavors, (although I think Pierce's data is even better wrt B.O.), Dr. F purposely (and with transparency) cherry picked sweet flavors for that study, not all flavors have those attributes.

New Study Claims E-Cigarette Vapor No More Dangerous Than Air
Study Shows E-Cig Vapor Has Similar Level Of Risk As Air.

That study used NJoys. Hardly representative of all ecigs, and not at all with those in our study. Are you saying that since we know about NJoys, we then immediately know about all vapor devices at all wattages? Its promising results, for sure, but I think generalizing to all vapor devices is really stretching it. Cigalikes do not produce significant aldehydes, in general.

And BTW, I am a co-author on the Farsalinos DA/AP study. Of course we cherry picked sweet flavors. We had very limited money to do the study and we went for flavors most likely to have DA or AP.

But I think you misunderstand my statement about flavors. I'm not talking about flavor compounds being toxic, I'm talking about thermal decomposition of flavor compounds to form all sorts of molecules that we don't know the toxicity, or even the identity of.

 

[Kurt]

Let me clarify: I am hopeful and optimistic that well-built correctly-used PVs can show similar results as the NJoys, but until those studies are actually done, its conjecture.

 

[Kent C]

That study used NJoys. Hardly representative of all ecigs, and not at all with those in our study. Are you saying that since we know about NJoys, we then immediately know about all vapor devices at all wattages? Its promising results, for sure, but I think generalizing to all vapor devices is really stretching it. Cigalikes do not produce significant aldehydes, in general.

I just picked two studies from a google search. There are many others we have seen here near monthly, that either compare ecig aerosol to air or like some of yours and Dr. F's (and other notables), that show significant differences between ecigs and cigarettes. I just thought that the "probably" wording was a bit much and something that could easily be used, as is the quote in my above post, by ANTZ to spin a rather positive study, to the negative, and out of context, as was done with Dr F's earlier work, where he had to write articles clarifying the results, as is the case many times, the ANTZ media is better than ours, and 'corrections' are not always published. And it was as I predicted at the time, btw. So it isn't the results of the studies I have a problem with, but some generalizations that are made about it, that would tend to be fodder for ANTZ.

And BTW, I am a co-author on the Farsalinos DA/AP study. Of course we cherry picked sweet flavors. We had very limited money to do the study and we went for flavors most likely to have DA or AP.

The 'cherry pick' wasn't a criticism but a description that was as I said - transparent - from the original study. And I know well that you were part of that.

But I think you misunderstand my statement about flavors. I'm not talking about flavor compounds being toxic, I'm talking about thermal decomposition of flavor compounds to form all sorts of molecules that we don't know the toxicity, or even the identity of.

I know what you were saying and there, again, have been other studies that have not show such toxicity, except in ANTZ studies where it seems the intent of the study and the methods used to produce them, were not any part of real world experience.

 

[Kurt]

Who is studying thermal decomposition products of flavors in e-liquids, and their toxicity?

 

[Kent C]

Who is studying thermal decomposition products of flavors in e-liquids, and their toxicity?

I meant in general there have been studies showing no toxicity using flavored eliquid, but.... to answer your question:

http://www.bat.com/groupms/sites/BA...e/DO9UQDZ8/$FILE/SRNT_2015_PD.pdf?openelement

ANTZ studies - showing some toxicity of course:
Carbonyl Compounds in Electronic Cigarette Vapors—Effects of Nicotine Solvent and Battery Output Voltage

with a listing of studies under 'Introduction'.

 

[zoiDman]

I meant in general there have been studies showing no toxicity using flavored eliquid, but.... to answer your question:

http://www.bat.com/groupms/sites/BA...e/DO9UQDZ8/$FILE/SRNT_2015_PD.pdf?openelement

...

Maybe I'm looking right at it and Can't see it.

But what Flavorings were Tested?

 

[Kent C]

Maybe I'm looking right at it and Can't see it.

But what Flavorings were Tested?

Flavor name or brands weren't mentioned - only "one composed exclusively from aroma chemicals (i.e. single substances with odour or fragrance properties), the other a single natural extract: cocoa shell extract".


CONCLUSIONS


1. THERE WAS VERY LITTLE EVIDENCE OF GC-AMENABLE THERMAL DEGRADATION OF THE FLAVOURS UNDER REALISTIC


USAGE CONDITIONS OF THE E-CIGARETTE.

2. HEATING FOR 5 MINUTES IN A CLOSED SYSTEM OVERESTIMATES FLAVOUR THERMAL BREAKDOWN IN E-CIGARETTES

I'm not saying that it is as extensive as the other study, just answering Kurt's question. Who is studying thermal decomp of flavors, etc.??

 

[Kurt]

Thank you, Kent! You are very correct, this study did look at thermal decomposition with flavors included. I absolutely should have remembered it, and I am very glad (and a bit humbled) that you brought it up. A good but

 

[Kurt]

Yikes, clicked post too soon. A moment please!