PG, immunotoxicant & neurotoxicant?

[Zelphie]

The issue I’m going to address may be old news by now but I often come across posts from people wondering why they experience certain effects that seem to be brought on by vaping. A few of these include skin rashes, shakiness, confusion, tiredness, gastrointestinal distress ect.

Scorecard.org The Pollution Information Site gives information of propylene glycols chemical profile. Ill link you directly to it....

PROPYLENE GLYCOL

I found the above link from a reference used in a Totally Wicked toxicology report. Ill include a link to that as well...

http://webcache.googleusercontent.com/search?q=cache:Vd4QE-YZciYJ:www.tobaccoharmreduction.org/lpdlabs.doc+totally+wicked+toxicology
(Html version because it’s a doc file you can download)
Scorecard.org listed PG as a recognized immunotoxicant, a suspected neurotoxicant, a suspected respiratory toxicant, and a suspected skin and sense organ toxicant.
Under “neurotoxicant”, it lists some general symptoms of neurotoxicants but it is not specific to any chemical.
"Neurotoxicants
Exposure to chemical substances can cause adverse effects on the nervous system (Neurotoxicity). Chemicals toxic to the central nervous system can induce confusion, fatigue, irritability, and other behavioural changes. Exposure to methyl mercury and lead cause central nervous system toxicity, and can also cause degenerative diseases of the brain (encephalopathy). Chemicals toxic to the peripheral nervous system affect how nerves carry sensory information and motor impulses from the brain to the rest of the body. The organic solvents carbon disulfide, n-hexane, and trichloroethylene can harm the peripheral nervous system, resulting in weakness in the lower limbs, tingling in the limbs (paresthesia), and loss of coordination."
http://scorecard.org/health-effects/explanation.tcl?short_hazard_name=neuro

From what I gather, glycerol seems as though it may be safer but if you search scorecard.org for glycerol, it is also listed as a suspected neurotoxicant but nothing is listed as recognized.
I like the fact that TW has toxicology reports and is more informative than some others. Otherwise we would not be able to make any type of semi informed choice as whether we vape or not. Just to be clear, the issues of concern here are not related to TW products but related to most e-liquid in general due to their base ingredients. It can also be found elsewhere that PG can effect the central nervous system, but I apologize I do not have any verifiable sources at this time.
Just to be clear I am not saying that you shouldn’t vape, nor am I saying that vaping isn’t better than smoking, comparing risks against risks, I still feel vaping generally wins, but potential risks have to be considered especially if you’re prone to certain problems, find them to bothersome, or cannot risk them due to certain conditions, and last but not least the potential unknown factor of long term use.
I now understand a wee bit better why those who sell e-cigs and e-liquid often include warnings with their products such as "vapors may cause drowsiness" and "don’t use if taking antidepressant medications". I tend to experience shakiness and confusion that I can’t attribute to any other cause when I vape moderately to heavily.
Like I said it might be old news, but I’m new to there!

 

[scinsc]

Thank you so much for this post Zelphie. I suffer from Peripheral Neuropathy and some of the information you linked to (neurotoxicants) could help zero in on my problem.
BTW, I have had this problem long before I started vaping and I only use VG.

 

[Drozd]

I think that you also have to take into consideration that there are different grades of PG..industrial vs comercial vs pharmaseutical

here's a link I find better than the one you had provided
Ethylene Glycol and Propylene Glycol Toxicity: What is Propylene Glycol | ATSDR - Environmental Medicine & Environmental Health Education - CSEM from the CDC's Agency for toxic substances and disease registry

basically in any case where there was any toxic response to PG it was administered either topically (over burns) or via IV in concentrations way higher than we could possibly get via vaping...

particularly convincing to me are a combination of these statements on the page I linked

"FDA considers an average daily dietary intake of 23 mg/kg of body weight to be safe for persons 2-65 years of age"

that's dietary so the absorption would likely be higher and that's 23mg PER kg of body weight so an average say 75kg (165 lb) person would have to ingest 1725mg of pg to hit that safe daily dietary intake

couple that with this:
"Half-Life
The elimination half-life of propylene glycol is about 4 hours."

Propylene glycol is metabolized in the liver by alcohol dehydrogenase to

•lactic acid, and then
•pyruvic acid
Both of these metabolites are normal constituents of the citric acid cycle and are further metabolized to

•carbon dioxide and
•water
About 45% of an absorbed propylene glycol dose is excreted by the kidneys unchanged or as the glucuronide conjugate.


so you'd have to be vaping the equivalent of ingested 1725mg of PG in the span of 4 hours to even break that safe threshold before it's turned into carbon dioxide and water and eliminated from the body...that's totally unlikely even for the heaviest of vapers


*as a side note I only vape PG as it's far more known and documented, and used in breathing treatments... than VG which is sold as a skin protectant and not labeled to be used internally...in fact there's a warning to NOT use it over deep puncture wounds and the like

 

[curiousJan]

I tend to experience shakiness and confusion that I can’t attribute to any other cause when I vape moderately to heavily.

Something else to consider is that these symptoms may be related to the use of too high a nicotine level. Shakiness and cognizant issues are the result for me when I'm vaping too heavily on a higher strength niquid.

Jan's

 

[Stephra]

Something else to bear in mind is that we intake PG through ecigs, but we also are exposed to PG in a number of other products. In another thread I saw a person who had problems with PG irritation say that they reduced their problems by zeroing in and eliminating some of the OTHER forms of PG they were exposed too (deodorant, food products, etc).

Perhaps considering TOTAL PG exposure is part of the equation?

 

[Zelphie]

Thank you Drozd for adding that information.
Nic is a neurotoxin but like others, that doesn’t mean it will necessarily hurt you, I suppose we all have to define what getting "hurt" means. I still can’t help being concerned due to warnings on e-liquid but little information regarding the warnings. It’s a bit like some of the artificial sweeteners that are considered generally safe to consume, they remain to be suspected of being a neurotoxin. The sweeteners probably won’t kill you, probably won’t even give you cancer since as far as I know it’s only done so in rats, but it may hypothetically cause mild depression or mild neurological problems, or it may do nothing.
For me this is an issue because I have mental neurological difficulties so I’m more concerned over this than most people might otherwise be.
Yes too much nic is a big no no! I usually vape low or no nic if I’m vaping a lot, but who knows why I react like that. That’s why I want to keep my eyes open to possible unwanted effects because there’s somewhat of an unknown element
And yes we do use and ingest PG in many many different things but I’m wondering if the concentration, frequency of use (all day) and heated inhalation may be somewhat different that how PG would act in the human body in the form of ingestion, topical, and even periodic breathing treatments but I don’t know.
As always, anyone with additional info is appreciated.

 

[nicnac]

What about the flavoring? To me that is the most suspect ingredient.

 

[Bageone]

My experience is far from scientific but, I suffer from end stage liver disease (10% function) and peripheral neuropathy. I have been vaping since Feb 2010, and I mean HEAVY vaping since then and have ZERO side effects from PG as far as liver and other.. the only side I get is that it is more drying to my mouth than pure vg.