Study--what is in the vapor we exhale?

[zoiDman]

zoiDman, what follows is from wikipedia and other informational websites, plus some figuring on my part (I'm sorry, but I have to get into the weeds here to interpret and comment on the results -- and bear in mind, I'm working right at the limits of my knowledge):

...

These three compounds seem to be totally innocuous in the tiny concentrations reported in the ClearStream study. Hopefully, Kurt (who is a biochemist in real life) will wander by to point out any errors in my analysis.

...

Perhaps my wording was poor.

What perhaps would have been a Better Post on my part would have been... I was surprised to see the amount of Methylethylketone and 1-ethyl-3-methylbenzene at the Same or Higher levels than in a Cigarette.

What also was somewhat Disturbing is the nature of Methylethylketone. MEK is a fantastic solvent and a known Carcinogenic. It can also is readily absorbed thru the Epidermal Layer. And more readily absorbed by the Soft Tissue of the lungs.

If there was this level of MEK measured in the Exhaled vaper from a e-cigarette user, I wonder how much MEK was inhaled and subsequently absorbed by the vaper?

 

[zoiDman]

Population's too small for it to be a valid study.

Do you mean "Sample" instead of Population?

 

[mostlyclassics]

MEK is a fantastic solvent and a known Carcinogenic. It can also is readily absorbed thru the Epidermal Layer. And more readily absorbed by the Soft Tissue of the lungs.

If there was this level of MEK measured in the Exhaled vaper from a e-cigarette user, I wonder how much MEK was inhaled and subsequently absorbed by the vaper?

And so it is all of those things, zoiDman. But the irritation and/or damage only occur at vastly greater concentrations than we vapers encounter, many orders of magnitude greater than found in the ClearStream study.

I suspect MEK is used in the manufacture of some cartos and clearos, and I suspect that's where the MEK came from in the ClearStream study. Presumably, they used brand-new cartos and/or clearos that hadn't had all the MEK leach out or evaporate yet.

Back when I used Stardusts, I used to repair cracks in the base with straight MEK, also known by the trade name of Ambroid. I was aware of the dangers of MEK in high concentration and for extended duration of exposure and never gave it a second thought given the very tiny concentration we vapers would face using Ambroid to patch our Stardusts.

 

[zoiDman]

And so it is all of those things, zoiDman. But the irritation and/or damage only occur at vastly greater concentrations than we vapers encounter, many orders of magnitude greater than found in the ClearStream study. ...

Agree.

And I not thinking so much about the amount of MEK and 1-ethyl-3-methylbenzene that is being Exhaled. More the amount the amount that is being Inhaled.

If I inhale say 40 ppm of MEK or 1-ethyl-3-methylbenzene, do I exhale the same 40ppm?

 

[mostlyclassics]

If I inhale say 40 ppm of MEK or 1-ethyl-3-methylbenzene, do I exhale the same 40ppm?

No, you would inhale more than 40 ppm of MEK or benzene to exhale 40 ppm, since the body does absorb some of those chemicals.

But what ClearStream reported was much, much lower concentrations of both chemicals present in e-cigarettes. Here's what I wrote in post #19:

• Methylethylketone (AKA MEK, or butanone, or model "cement," is a solvent widely used in many industrial processes). In 2005, the EPA removed MEK from the list of hazardous air pollutants, concluding "potential exposures to butanone [i.e., MEK] emitted from industrial processes may not reasonably be anticipated to cause human health or environmental problems." MEK can cause lung irritation and birth defects in mice, but at concentrations of 3,000 parts per million (ppm) (or greater), with no problems reported below 1,000 ppm. The ClearStream study reported 4.2 (for regular cigarettes) or 4.4 (for e-cigarettes) micrograms per cubic meter. A cubic meter of air at sea level weighs 1.2 kg. If you do the math, the 4.2 or 4.4 micrograms per cubic meter reported work out to a concentration of 0.0035 or 0.0036 ppm (assuming I did the math right).
• 1-ethyl-3-methylbenzene (AKA benzene, comprising several percent of most gasoline blends). OSHA has set a safe limit of 1 ppm in air per 8-hour workday and 40-hour workweek. The ClearStream study reported 0.2 or 3.4 micrograms per cubic meter, which works out to 0.000167 or 0.00283 ppm (again, assuming I've done the math correctly).

The threshold of damage from MEK (at least for mice) is somewhere above 1,000 parts per million (and likely at the 3,000 ppm level); what ClearStream reported for e-cigarettes was 0.0036 parts per million.

And the 1 ppm benzene workplace threshold which defines the "safe" level for OSHA, is vastly higher than the 0.00283 ppm from the ClearStream reported concentration in e-cigarettes.

 

[praetor91313]

Do you mean "Sample" instead of Population?

Oops, you're right. The correct term's "Sample size".

 

[zoiDman]

...

The threshold of damage from MEK (at least for mice) is somewhere above 1,000 parts per million (and likely at the 3,000 ppm level); what ClearStream reported for e-cigarettes was 0.0036 parts per million. And the 1 ppm benzene workplace threshold which defines the "safe" level for OSHA, is vastly higher than the 0.00283 ppm from the ClearStream reported concentration in e-cigarettes.

I think I just found a "units" problem with my math.

How did you come up with your .00283 ppm for the MEK?

 

[zoiDman]

Oops, you're right. The correct term's "Sample size".

OK...

What sample size would you suggest?

And are we sampling to make an Inference about a Population that has some Normal Distribution?

 

[mostlyclassics]

I don't zoiDman. As I said,

. . . the 1 ppm benzene workplace threshold which defines the "safe" level for OSHA, is vastly higher than the 0.00283 ppm from the ClearStream reported concentration in e-cigarettes.

The 0.00283 ppm calculation is for the reported benzene, not the reported MEK.

I edited my post #25 to break that two-sentence paragraph into two paragraphs to make it clearer.

 

[Kurt]

I think ppm here for air sampling would be micrograms/L of air, rather than per mass of 1 cubic meter of air. But even with this distinction the value of 4.2 microgram/cubic-meter would be 0.0042 ppm, or 4.2 ppb. Very low indeed.

I would ask not why ecigs are as high as cigs, but rather why cigs are as low is ecigs. Both are extremely low in ketones, and I'm not sure why. Not sure also why ecigs emit any MEK, even if very low.

BTW I am an organic/theoretical chemist, not a biochemist. I know some biochem, but it is not my specialty.

 

[mostlyclassics]

Hi, Kurt --

Thanks for checking over this thread! I double-checked the volume they used: "[μg/m3]" (which I interpreted to be micrograms per cubic meter). Seems strange to me, too, but that's what they used.

Sorry about the misattribution of your professional specialty!

 

[SloHand]

There appears to be some very good resources posting here. I would like to pick your brains to know if The Occupational Exposure Limits for Nicotine in this table can be simplified for the layman. How can this be translated to the levels that we typically use (i.e. 18mg) and how much volume would constitute an 'exposure' at our levels? I'm assuming that they are referring to pure liquid nicotine but I'm not even sure of that.

The Occupational Exposure Limits for Nicotine in this table refers to Time-Weighted Average Limit (TWA) 0.5 mg/m3 and no Short-Term Exposure Limit (STEL) / Ceiling Limit (C). What does this mean in the real (vaping) world?

We know from the study quoted in this post that the vapour exposure is small or next to none but what I'm wondering is the exposure to the liquid itself as in a spill and there being skin exposure with the liquid.

What would constitute a dangerous exposure level/volume of 18 mg strength juice?

 

[Faylool]

Just love the avatar OP
Article is great too

 

[Projectguy]

Population's too small for it to be a valid study.

I a traditional sense yes but disagree in this case after all how many analogues need to be combusted or litres of juice need to be vaporized to determine the exhaled compounds?

 

[praetor91313]

Yes, but it was my impression that the greater the sample size, the better the precision of the result and the less impact unknown or excluded variables would have.

For example, how were the parameters (nicotine, TOC, etc.) collected? Does emissions from a cigarette (smoke) differ from the emissions from an ecig (vapor) differ? And if so, how would these affect specimen collection? There are a lot of known and unknown variables which have to be considered and it was my understanding that increasing the sample size would eliminate some errors.

 

[praetor91313]

We know from the study quoted in this post that the vapour exposure is small or next to none but what I'm wondering is the exposure to the liquid itself as in a spill and there being skin exposure with the liquid.

What would constitute a dangerous exposure level/volume of 18 mg strength juice?

I couldn't find the actual (quantitative) absorption rates of nicotine through skin exposure but some articles state that it is significant (some use the term "readily passes" from dermal contact). The lethal dose for children is 0.1mg/kg so in a 20kg child, even a 6mg nicotine fluid exposure has a potential to kill them.

 

[praetor91313]

Here's another study posted by pbusardo on facebook: Levels of selected carcinogens and toxicants in vapour from electronic cigarettes -- Goniewicz et al. -- Tobacco Control

This blog page from Dr. Michael Siegel contains commentaries about the article posted above. Again, I got it from pbusardo's post at facebook. Kudos to Phil for spreading the good news!
The Rest of the Story: Tobacco News Analysis and Commentary: New Study of Electronic Cigarette Vapor Confirms that E-Cigs are Much Safer than Regular Cigarettes