The main issue with ecig tests is that any test has to be done on the vapor, since what is in the liquid is basically irrelevant. You aren't inhaling the liquid, you are inhaling vapor produced from the liquid by a specific process that will pull a certain percentage (but not all) of a given constituent out into the vapor, and may not transfer some constituents at all.
Whatever is in the solid or liquid phase before conversion to the gas phase is not relevant except as an easily-analysed indicator of what to look for in the vapor, as that is proven to be many times lower and in the case of water/PG-based vapor, much harder to isolate. As examples:
- A cigarette contains about 18mg of nicotine, but only about 5% of that is delivered to the smoke - about 0.9mg. The process is extremely inefficient.
- The FDA found a small amount of DEG contamination (about 1%) in one sample of eighteen cartos tested in 2009 (a result that could well be described as excellent as regards safety and quality). It was not detected in the vapor.
[Note that in order to be poisoned you would somehow have to drink a gallon of the liquid inside the affected cartos.]
E-liquid contains on average 18mg of nicotine per ml of liquid, but we don't know exactly how much is in the vapor - indications are that it is about 50% of that but this is simply a guess. So only about half the nicotine makes it into the vapor; and some of that may not be bioavailable as it is locked by PG. All these issues are simply guesses though until real research is carried out.
It is also not acceptable to heat the liquid in order to produce vapor to measure - you have no idea at all if this exactly replicates the nebulising process within an ecig. If someone were to do that it would be yet another example of the complete incompetence shown in the conduct of vapor tests to date.
Testing e-cigarette vapor is difficult and nobody has done it correctly and published the results, to date. All the available tests show incomplete results - a 'test' is not deserving of the name if 15% or 20% of the constituents are not identified, or if all the constituents are given and add up to almost 100% but water is not mentioned (!); and if chemicals such as phenols are present that were produced by melting plastic as a result of operating the equipment inverted; and if the photos of the test rigs show a method that could not possibly work.
It seems that labs know about as much about ecigs as the FDA do - take a look at the FDA's e-cigarette page on their website where they show a cartomizer being recharged in a battery charger. If you employ incompetents then these are the results you can expect.
Last edited by rolygate; 05-04-2013 at 10:31 AM.
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<speculation>Most likely cigarette companies have done rather complete tests on ecigs. Probably extracted the vapor with something similar to those machines we used to see on BT TV advertisements many years ago. Remember the machines into which they stuck a lighted cigarette and the machine puffed on the cigarette to extract smoke? I don't know how they tested the vapor, but probably the same way they tested the smoke. I guess no one outside of BT has seen the results.</speculation>
Last edited by TTK; 09-15-2012 at 03:20 PM.
Many Thanks for the info on this important topic.
I think some of the posts are being a little hard on researchers as at least some of the analyses refered to in this thread are two-a-penny commercial lab reports rather than real research. These probably only cost a few hundred dollars and so are limited. A much more rigorous analysis can be found at http://healthnz.co.nz/RuyanCartridgeReport21-Oct-08.pdf. Even this is not, strictly speaking, a formal scientific study (not published or peer-reviewed and funded by Ruyan) but is the closest I've seen to actual research on eliquid analysis.
The MSDS can seem alarming but everything is toxic depending on the concentration, even pure water (yes people have died from drinking too much water). So the important thing is to look at the LD50 numbers to put this into the correct perspective.
For example for PG the LD50 is:
This LD50 means that 50% of rats will die if they consume orally at least 20 grams of PG for every 1 kg of body weight. So the average size rat (500g) would need to drink 10 millilitres of PG before it was toxic (at least half of the time). By comparison the rat LD50 for seawater is 3000mg/kg, so PG is about seven times safer to drink than seawater. Pure water has an rat LD50 (greater than 90ml/kg).
There is a real need for more rigorous research like the report above. Problem is this is really difficult to do even if you had unlimited research funds. Trying to work out exactly what all the constituents are in e juice is very difficult, let alone trying to work out what is converted in vapor and what interactions occur in the mouth, lungs, blood etc. A complete assessment is very difficult to achieve (have a quick look at the limitations/disclamers on any meds you have or on products like nicobate, champix, varenciline etc.). Suprisingly little is known about the health consequences of many pharmaceuticals and we generally rely on some authority to provide us a determination that it is safe (FDA etc), although they dont know any more than the available research, more of a best guess based on the limited evidence and excluding the more obvious problems.
So while there is a real need for more research, the avaible evidence referred to in this and other threads indicates that the constituents in eliquid become toxic at levels 100 to 1 million times greater than the concentrations in ejuice. As reported, these levels are actually much lower since many constituents are exhaled following inhalation. From an admitedly brief reading, the main concerns seem to be the unknown toxicty of some of the flavours used, although even these may not be a problem at common vaping temps. Still as often advised in these forums, best practice is to limit the flavours you add to ejuice.
One thing you can do while waiting for the research to catch up with you is use your body as a test tube and do your own analysis. Like me you probably smoked about a packet a day. Like me, you probably noticed almost immediately you didnt constantly crave a cigarette and smell like an ashtray. When you did try one you couldnt take more than a few puffs. Your brain had already began to disassociate the unpleasant and toxic effects of cigarette smoke from nicotine. At this point, cigarettes were history and you were a member of the Vaping Nation.
Then around two weeks later you noticed your smokers cough had disappeared. After 1 month or so people began commenting that your skin tone and texture had changed dramatically, you actually look healthy. Then you began to notice you could enhale a rapid deep lung full of air without coughing. A little later you were late for a meeting and ran up a couple of flights of stairs. After sitting down it began to dawn on you that something was missing. That's it...you werent puffing, wheezing, sweating profusely.
You dont need a doctorate to work out that vaping nicotine is therefore about 23.02 zillion times safer than smoking tobacco. You also shouldnt need a doctorate to understand that vaping isnt 100% safe, nothing is. Can it be made safer, of course it can be but we need to wait for more research. Meantime I think the ECF forums like this are the best place to keep yourself up todate with current knowledge about health issues and research.
PS, in the orignal post 'dehydrate' should be changed to hydrate. PG is very miscible in water and if you get any on the skin or eyes a splash of water will prevent any irritation occuring.
Last edited by Vap_ingBilly; 01-11-2013 at 12:52 AM.
That Ruyan study is a great read, thanks for posting the link. We need some zealous post grad students to do their doctorates on e cigs as alternatives to analogues. We may then get some hard lab research as well as useful statistics on the efficacy of vaping as a smoking cessation tool.