Relook at Propylene glycol and it's safety aspects

[nopatch]

I am doing some literature search On Propylene glycol usage and Find Most of the assertions in vaping forums to be misguided or outright Lies.

Fact:No published toxicity data exist on humans exposed chronically to PG vapors either occupationally or from environmental exposures.

In a study Rats were exposed to a maximum of up to 700 ppm(0.07%) of Propylene glycol concentration and found to suffer from nasal hemorrhaging and ocular discharge beginning the second week of exposur.LInk :Spacecraft Maximum Allowable Concentrations for Selected Airborne Contaminants: Volume 5

Very Short term Human exposure studies shows significant problems:

[FONT="]TABLE 16-2[/FONT][/B][FONT="] Toxicity Studies of Propylene Glycol (Inhalation Exposures)[/FONT]
[FONT="]Exposure Concentration[/FONT]
[FONT="]Form of Administration[/FONT]
[FONT="]Species[/FONT]
[FONT="]General Effects[/FONT]
[FONT="]References[/FONT]
[FONT="]Range, 176 ppm to 851 mg/m3; geometric mean, 309 mg/m3; 1- min exposure at several different times[/FONT]
[FONT="]Aerosol spray[/FONT]
[B][U][FONT="]Human [/FONT][/U][FONT="]volunteers[/FONT]
[FONT="]Data on tear-film stability, rhinometry, lung function tests (dynamic spirometry), symptom assessments were collected; reported significant ocular irritation and throat irritation; some breathing difficulty.[/FONT]

[FONT="]Wieslander et al. 2001[/FONT]

Link: [URL="http://www.nap.edu/openbook.php?record_id=12529&page=319"]Spacecraft Maximum Allowable Concentrations for Selected Airborne Contaminants: Volume 5[/URL]

 

[eyebrook]

does that mean i need to see if I have a nosebleed after vaping?, or will I carry on feeling better than i did when I smoked cigs, have you got an answer because i sure as heck dont.But i feel a lot better

 

[nopatch]

The Only Long term Propylene glycol(and/Or Glycerin/glycerol) exposure is,not strangly, by Regular Cigarette smoking.

I have made some basic calculations to arrive at about 1% humectant(Pg and Vg) concentration in Inhaled cigarette smoke and for "Electronic cigarette" smoking the value is 10%.

The Inhaled Vapor from e-cigarette device contains appprox 10% glycols (Pg And/or VG).In PPM values it is 100000.

 

[nopatch]

does that mean i need to see if I have a nosebleed after vaping?, or will I carry on feeling better than i did when I smoked cigs, have you got an answer because i sure as heck dont.But i feel a lot better

I am not a medical professional, so i will have no idea how to answer that question.Some Vapers,it appears are displaying some or All the symptoms mentioned in the above study.

 

[nopatch]

Some enthusiasts cite FDA clearance for Propylene Glycol as food additive to imply that Propylene Glycol is safe for inhalation.

This premise is totally wrong because Vegetable oil mist(Vapor; in layman terms) exposure limit, as per CDC, is less than 10mg/m3 or 10 ppm approximately.

Ref: CDC - NIOSH Pocket Guide to Chemical Hazards - Vegetable oil mist

 

[Krisb]

I do not believe anyone on any e-cig forum have ever claimed e-cigs to be completely without risk. I have not, however, come across a single thread where someone has posted the side effects you have mentioned.

 

[eyebrook]

i dont recognise the FDA thats Usa and i understand you saying that there might be a problem with excessive exposure with pg to the lung, but where are the definitive studies, do you have records of tests or are you assuming based on linear testing that the results apply to us, please clarify, results taken out of context are meaningless

 

[nopatch]

I do not believe anyone on any e-cig forum have ever claimed e-cigs to be completely without risk.

That is correct.But there is Lot of Information out there that claims otherwise.

I have not, however, come across a single thread where someone has posted the side effects you have mentioned.

I read plenty of people complaining about breathing/cough problems in this very section of this forum.

 

[eyebrook]

Let me ask you a question, are you in Uni? doing a dissertation? or bored, or maybe a bit of free research at our cost?

 

[nopatch]

i dont recognise the FDA thats Usa

I haven't read anything useful from FDA resources regarding Propylene glycol or Glycerin.

and i understand you saying that there might be a problem with excessive exposure with pg to the lung, but where are the definitive studies, do you have records of tests or are you assuming based on linear testing that the results apply to us, please clarify, results taken out of context are meaningless

I started my post with the assertion that there are No Studies whatsoever regarding Long term exposure to propylene Glycol and/or Glycerin

 

[eyebrook]

So why are you scaremongering by posting studies, and you didnt answer my post about Uni etc

 

[nopatch]

Let me ask you a question, are you in Uni? doing a dissertation? or bored, or maybe a bit of free research at our cost?

Actually i was very hopeful in the beginning that i can get rid of smoking by switching over to Vaping.After carefully going through all the available resources i came to the conclusion that there is really no clue regarding the longterm effects of vaping.

I don't have an idea what is Uni.No, i am not doing any dissertation.Yes,I might be bored and have plenty of time on my hand for another week.

 

[Raenon]

Some enthusiasts cite FDA clearance for Propylene Glycol as food additive to imply that Propylene Glycol is safe for inhalation.

This premise is totally wrong because Vegetable oil mist(Vapor; in layman terms) exposure limit, as per CDC, is less than 10mg/m3 or 10 ppm approximately.

Ref: CDC - NIOSH Pocket Guide to Chemical Hazards - Vegetable oil mist

PG is not vegetable oil, and honestly, for you to call it such makes you look foolish.

Moreover, multiple studies HAVE been done on inhalation on humans, and PG vapors have been approved by the EPA for use as an air disinfectant.

"Unlike other pesticides for which EPA has followed a cumulative risk approach based on a
common mechanism of toxicity, EPA has not made a common mechanism of toxicity finding for
propylene or dipropylene glycol and any other substances. Neither propylene nor dipropylene
glycol appear to produce a toxic metabolite produced by other substances."

http://www.epa.gov/oppsrrd1/reregistration/REDs/propylene_glycol_red.pdf

In 1942, The American Journal of Public Health had this (and more) to say:
"The report of the 3 years' study of the clinical application of the disinfection of air by glycol vapors in a children's convalescent home showed a marked reduction in the number of acute respiratory infections occurring in the wards treated with both propylene and triethylene glycols. Whereas in the control wards 132 infections occurred during the course of the three winters, there were only 13 such instances in the glycol wards during the same period. The fact that the children were, for the most part, chronically confined to bed presented an unusually favorable condition for the prophylactic action of the glycol vapor."

http://www.ajph.org/cgi/reprint/36/4/390.pdf

ETA For the layman: Not only did no one identify any harm coming as a result of the PG inhalation, the kids in the exposed areas did BETTER than the ones who were not exposed to PG.

So, exactly why are you here?
Just another Anti-Vaping plant, I suppose?
Did you bother doing any real research before arriving at your opinion?

 

[oldsoldier]

I'm all for spreading the knowledge, but let us also take into account how much exposure we are talking about. Results taken out of context are pretty useless and only feed into the FUD factor.

Some thoughts just off hand that you might also want to consider in your research.

Propylene glycol is used as the base in inhaled asthma medications. This would seem to indicate that it is not significantly harmful or a major irritant.

Here is a study done in the 1940s http://www.ajph.org/cgi/reprint/36/4/390.pdf

some information about glycol and smoke machines : http://zeecigs.com/PDF/smoke-machine-glycol-finalreport.pdf

 

[john doe]

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1740047/pdf/v058p00649.pdf


It sounds like the same person that comes here every now and then telling us that ecigs are killing us.

 

[John Phoenix]

I started my post with the assertion that there are No Studies whatsoever regarding Long term exposure to propylene Glycol and/or Glycerin

Well there ya go. I have heard this said many times from CASAA or other tobacco harm reduction advocates. This is nothing that anyone on ECF is denying. We simply do not have these studies. We do have studies that tell us how harmful smoking tobacco is and it has to be much worse than inhaling PG alone. We are taking in 1 or 2 chemicals (besides nicotine) that is generally considered as safe compared to 69 cancer causing chemicals and 4000 other chemicals that does God only knows what to our bodies.

What about PG's use in inhalers? Surly they must have done studies on that because PG has been in use for asthma patient inhalers since the 1950's. I'd say your search missed some information.

Ah.. I see OldSoilder beat me to it.

 

[john doe]

Nearly every eye drop sold has PG and/or VG listed as the major ingredient. If they were harmful to eyes I don't think the companies selling these would be in business long.

 

[eyebrook]

my last reply seems to have got lost,you are researching with an agenda i think, you mentioned lies in your first post, who are you to speak about lies, that's what you seem to have been doing and i stop there have a good day dude, im going to bed

 

[John Phoenix]

Actually i was very hopeful in the beginning that i can get rid of smoking by switching over to Vaping.After carefully going through all the available resources i came to the conclusion that there is really no clue regarding the longterm effects of vaping.

So are you saying you would rather keep smoking and putting 69 cancer causing agents and 4000 other chemicals into your body as opposed to perhaps 3 that do not cause cancer?

 

[oldsoldier]

Closing this thread before it turns into a flamefest. It has already run its course as far as I am concerned. if the OP wishes to reopen a new post with new information presented in a non trolling fashion we can continue the discussion, but for now it is done.