Why Johnsons Creek clogs atomizers

[Schroedinger's cat]

The mixing could be the main problem, but Bertrand is saying that PG has often been contaminated with PO, according to the book in which he found his info. Another thing I'd like to know is whether, in the presence of PO, one would always get the polymerization in a visible manner.

Edit: Bertrand beat me to it....

 

[Bertrand]

Another thing I'd like to know is whether, in the presence of PO, one would always get the polymerization in a visible manner.

Yeah. It seems that it needs fairly specific conditions, since I couldn't reliably replicate it. And probably you need a decent concentration of it, too. It's unlikely that *all* PG is contaminated to a sufficient degree. Perhaps some separation occurs (they have radically different boiling points, and presumably differ in other ways) so that perhaps if you pull the stuff off the top, you get the PO, if you pull the stuff off the bottom you get PG. The more I learn, the less I want to know... hehehe

Propylene oxide won't do it alone, which is why people unfairly blame it on JC. According to the wikipedia article for polypropylene glycol (the polymer produced by propylene oxide), "With a multifunctional initiator like glycerine, pentaerythritol or sorbitol the polymer branches out."

 

[Schroedinger's cat]

So, in the presence of polymerization, one could be pretty sure that there is PO around. If no polymerization occurs, however, there could still be some PO contamination. It could be either that one step is missing to trigger the reaction, or that the amount of PO is too small to trigger it. Did I get this right? If this is the case, PG should really be replaced by VG by the manufacturers.... Where is a chemist when you need one?

By the way, what is the B&H you are back on? Regular tobacco? I take it that your mild concern has evolved further, if that is the case....

 

[Silver]

Hi all,

I've been in contact with Dr. Laugesen by e-mail before. Would you like me to bring this thread to his attention ?

Cheers,
Silver

 

[Bertrand]

That's about right. Scary. Especially since none of the saftey researchers on ecigarettes appear to have looked into the production methods of PG in any detail. The original article regarding PO contamination is this one:

Kagan, M.R., Cunningham, J.A., Hoffmann, D.
Propylene glycol. A precursor of propylene oxide
in cigarette smoke. 53rd tobacco Science
Research Conference, Abstract #41 and #42,
1999

Well, not quite - obviously you want the article, rather than just the abstract, but that's how it is cited in the book.

I couldn't find it online, (only citations to it) but the source sounds credible enough, and I can't see them having increased safeguards on PG manufacture since then.

While I probably won't use any PG-based liquid any more, I intend to get some to send to a lab, assuming differential testing for PO isn't too expensive. If I'm right, this is deadly, and I don't want to look back and say to myself, "yeah, I really should have followed up on that one."

Unfortunately, the news, if it comes, can only be bad: a negative result would only mean that particular batch is okay.

B&H = Benson & Hedges. Yes, my mild worry got upgraded, but I'm trying not to be alarmist. Once I clean out the atomizers and cartridges (and get over my shock) I will possibly return to JC NPG.

 

[Schroedinger's cat]

I definitely think we need some expert opinion here, and Dr. Laugesen is an expert, and also has contancts with chemists. It seems a good idea to ask him.

Here is what the EPA has to say about propylene oxide:
Propylene oxide | Technology Transfer Network Air Toxics Web site | US EPA

 

[Silver]

I agree and am in the process of preparing an e-mail to him as we speak...

Cheers,
Silver

 

[Schroedinger's cat]

I don't know enough about chemistry to even try to figure this out. However, if someone is able to delve into this, there is a whole dissertation about how to obtain PO from PG here:
http://edt.missouri.edu/Fall2007/Thesis/AbrahamS-120607-T8527/research.pdf

Alternatively, the abstract (and the link to the whole thesis) can be found here:
Electronic Thesis and Dissertation Archives - University of Missouri - Columbia

Thank you, Bertrand, for this (although I hope it turns out to be not a major concern...), and SIlver, for contacting Dr. Laugesen.

 

[Silver]

The e-mail with a link to this thread has been sent. I will let you know if I receive a reply from Dr. Laugesen.

Cheers,
Silver

 

[Bertrand]

Thanks, Silver. While I am likely wrong about the mechanism behind the goop formation, I am now practically certain that e-liquid and cartridge liquid is often contaminated with PO.

 

[Silver]

Without trying to be mean in any way Bertrand, I soooo hope you are wrong about this (although it seems to be a meager hope at this point, call it clutching at straws) !

No offense intended of course !

Cheers,
Silver

 

[Schroedinger's cat]

From the EPA sheet it appears that some symptoms should appear if one is exposed to PO. Perhaps this is not necessarily the case if the doses are small enough, though. In any event, manufacturers should switch to VG. I think it was recommended in the report from NZ, too.

 

[Bertrand]

From the EPA sheet it appears that some symptoms should appear if one is exposed to PO.

"Inhalation:
Vapor is irritating to the mucous membranes and upper respiratory tract. May cause depression of the central nervous system. Symptoms may parallel those from ingestion exposure."

"Ingestion:
Corrosive. Swallowing can cause severe burns of the mouth, throat, and stomach. Can cause sore throat, vomiting, ......... May cause depression of central nervous system. Symptoms may include headache, nausea, vomiting, drunkenness. incoordination, dizziness, and general depression. May cause abnormal liver function as detected by laboratory tests. "

Lots of people have reported an irritated throat, chest, wooziness, digestive upset, nausea, etc. Problem is, these are as easily attributed to nicotine. Cancers would just get attributed to a history of smoking.

Perhaps Kate should add "propylene oxide" to her poll of "what causes a throat hit" hehehehe.

 

[Di]

if this turns out bad,
what are we going to vape,
I have quit smoking after 45 years,
please tell me this is not dangerous

I do not want to go back to cigarettes again.

Di ....

 

[Frankie]

if this turns out bad,
what are we going to vape,

Well, if I understood it right, we are going to vape glycerin, non-PG-PO-whatever liquid from America - and buy LOTS of atomizers.

 

[Di]

that means spending a fortune for e-liquid from usa shipped halfway round the world,
more expense,

maybe just give up the nicotine
and vape glycerine with pure flavours.

Di .....

 

[Schroedinger's cat]

"Inhalation:
Vapor is irritating to the mucous membranes and upper respiratory tract. May cause depression of the central nervous system. Symptoms may parallel those from ingestion exposure."

"Ingestion:
Corrosive. Swallowing can cause severe burns of the mouth, throat, and stomach. Can cause sore throat, vomiting, ......... May cause depression of central nervous system. Symptoms may include headache, nausea, vomiting, drunkenness. incoordination, dizziness, and general depression. May cause abnormal liver function as detected by laboratory tests. "

Lots of people have reported an irritated throat, chest, wooziness, digestive upset, nausea, etc. Problem is, these are as easily attributed to nicotine. Cancers would just get attributed to a history of smoking.

I had considered the irritated throat, usually attributed to PG, reported by many people -although it did not appear to be as bad as "severe burns". I must have missed many of the posts about nausea, wooziness, etc, because I did not have the impression that these were very prevalent symptoms. Also, it seemed to me that, for most people, many of these symptoms got better after a few days, which I would not expect to happen with a poison.

Most people on this forum seem to feel better with e-smoking -except when they overdose on nicotine. (Of course, those on the forum may be those who feel good). On the other hand, I guess that, if the dose of PO is small enough, one may perhaps get away with few or no symptoms.

Bertrand: you seem convinced that this could be worse than smoking. Is this based on the assumption that most of our PG-based juice is contaminated?

 

[Bertrand]

Bertrand: you seem convinced that this could be worse than smoking. Is this based on the assumption that most of our PG-based juice is contaminated?

Calmed down a bit now. hehehe.. Sorry if I got a bit worked up there. It doesn't seem to be worse, but I would imagine a number of people (me included) were sort of hoping the only drawback would be the cardiovascular system - not a cancer risk. Again, I should repeat, this is just a concern: nothing is proven. Perhaps the 12-100ng they detected in various cigarettes' smoke was mostly from thermic degradation of the PG humectant at temperatures far higher than you get in an e-cigarette.

 

[TropicalBob]

Ooooooo. Now I'm sorry I flirted with the girl in front of me the entire semester of chemistry. This is beyond me! But, considering these two quotes from your Wikipedia reference, I'm curious:

Propylene oxide degrades into propylene glycol in the presence of water, a process which is accelerated by the presence of acid or base. Propylene oxide is a probable human carcinogen.

Our liquid has water. It has acid. But ... if it is contaminated with propylene oxide, why doesn't the PO degrade to PG which could then be safely vaped?

Propylene oxide is also used in the production of propylene glycol

So odds are good that commercial PG might contain this carcinogen? And if enough is present, it creates your goo?

See how confused I am at this point? If Bertrand can articulate a question for Dr. Laugesen in a way he can answer, I'll be happy to contact him. I have a folder of emails from our earlier exchanges that I used in writing my SmokeShop article. He was more than willing to answer any intelligent question. I'm just not educated enough in this field to frame the question.

 

[Kate]

I'm out of my depth here, I don't completely understand what this all means but if Silver has directed Dr Laugesen to this thread then we should be in good hands.

My feeling is that the Dr would be best placed to theorise about the observations that have been shared here and hopefully will feedback his thoughts to Silver or on the thread himself.

Ignorance is bliss they say but a little knowledge can be a dangerous thing. I'm not going to worry until a scientist, chemist or medic raises the alarm.