propylene glycol, and glycerine...... see this, if you havent already.

[RestrictedAccess]

There's a lot of people that sound like they're getting a little defensive about this. I think there's an important thing to be considered regarding this thread, and, for that matter, and devil's advocate argument about PG. The FDA is looking for a reason to ban e-cigs. Tobacco companies are chomping at the bit to get them off the market because they're a threat to sales. One of the best ways to ban a substance is to increase public fear of said substance - that's what they did with ........ and alcohol, and it's what they're doing with cigarettes and e-cigs.

We need to arm ourselves with an understanding of the health effects of what we inhale, because there will come a time when these studies are quoted to us by public officials looking to ban e-cigs. The OP's argument should be seen as something to practice on (and be grateful for).

I don't believe that any negative effects of PG should instantly invalidate the benefits of e-cigs, but I do think that the study should be picked apart so we're ready to refute naysayers who would use said study as a basis for claiming e-cigs are bad for us.

[Asha Vahishta]

I just found this:
(link removed)

Clinical trials on electronic cigarettes containing propylene glycol were carried out in New Zealand by Dr. Murray Laugeson of Health New Zealand and can be found on the website of SS Choice LLC (link removed) under the tab "Media Coverage." Far from posing a threat to our health, the propylene glycol in e cigarettes might just keep us healthy.

That's encouraging info.

From the MSDS the TWA is 10mg/m³ which means that OSHA (overly cautious) says that you can work 8hr/day 40hr/week in an environment which contains 10mg of PG in every m³ of air with no harmful long term effects.

I may have made some mistakes or incorrect assumptions in the following, so don't trust my analysis, do it yourself.

average lung capacity 4.5L = 0.0045m³

10mg/m³ X 0.0045m³= .045mg of PG per inhale would be considered safe by OSHA

Does anyone know the approximate mg of PG in a puff?

[satoshi]

I just found this:
Propylene glycol in e cigarettes might keep us healthy, says researcher..


Heres the link: Propylene glycol in e cigarettes might keep us healthy, says researchers

This is a press release written by the company...the author is the site linked at the end. Google 'ss choice' as well.

The Time article it cites is from the 1940's, and the New Zealand study was funded by Ruyan- an e-cig manufacturer.

[Steamin' E.]

That's encouraging info.

From the MSDS the TWA is 10mg/m³ which means that OSHA (overly cautious) says that you can work 8hr/day 40hr/week in an environment which contains 10mg of PG in every m³ of air with no harmful long term effects.

I may have made some mistakes or incorrect assumptions in the following, so don't trust my analysis, do it yourself.

average lung capacity 4.5L = 0.0045m³

10mg/m³ X 0.0045m³= .045mg of PG per inhale would be considered safe by OSHA

Does anyone know the approximate mg of PG in a puff?

A KR8 cartomizer supposedly holds 0.7mL of juice (approximately 0.7mg), and supposedly provides 200 puffs. But let's say 155 puffs to be more conservative. This works out to 0.0045mg per puff, or one-tenth of your calculated OSHA-safe level of .045mg.

Keep in mind, too, that not every breath a vaper takes is in the form of a drag off his or her PV. They get to breathe normal air most of the time, unlike the factory worker who spends 40 hours a week breathing PG vapor at the OSHA threshold.

[Steamin' E.]

A KR8 cartomizer supposedly holds 0.7mL of juice (approximately 0.7mg), and supposedly provides 200 puffs. But let's say 155 puffs to be more conservative. This works out to 0.0045mg per puff, or one-tenth of your calculated OSHA-safe level of .045mg.

Keep in mind, too, that not every breath a vaper takes is in the form of a drag off his or her PV. They get to breathe normal air most of the time, unlike the factory worker who spends 40 hours a week breathing PG vapor at the OSHA threshold.

Oops. 0.7mL of ejuice weighs 0.7g, not 0.7mg. And, upon double-checking, it seems that a KR8 cart will hold a full mL of juice (of course, if your juice is 30% VG, you'll still be at 0.7g of PG per carto). That'll change things a bit (a ton, actually)! It means that each puff (assuming you can drain the cart in 155 puffs) contains 6.45mg of PG, or 140 times beyond your calculated OSHA-safe level of .045mg/per inhale.

At rest, I take roughly 15 breaths/minute = 900 per hour
While working in the PG factory, I'll guess that the factory worker is breathing at, conservatively, 17 breaths/minute = 1020 per hour
1020 X an 8-hour day = 8,160 breaths...

8,160 X OSHA threshold of .045mg/lungfull = 367mg/workday

Taking 24 drags an hour for 17 hours a day = 408 drags/day
408 X 6.45mg = 2.63 grams per day for a 2+ carto-a-day vaper
Obviously, for the 1+ carto-a-day vapers, that gets cut to about 1.3 grams per day (well below the previously-mentioned WHO 1.88g daily limit for a 75kg man).

I guess it comes down to whether you believe OSHA or WHO... and how much you vape.

I personally have never tried an electronic cigarette, so for all I know, all the above assumptions might be all but worthless.

Maybe the safest route (barring allergies/sensitivity) would be the middle ground, either alternating days between VG and PG, or always vaping a juice with fairly balanced VG/PG ratios.

Keep in mind, I'm currently the most noobed-out noob on ECF.

[Asha Vahishta]

Thanks Satoshi,
It’s always important to know who funded the report and I didn’t check.

Steamin' E.
Your numbers look good to me but I have a tendency to be sloppy (see above)
Lets recalculate the OSHA # for a 7 day week

367mg/workday X 5 days = 1835mg/week
1835mg/week divided by 7days/week = 262mg/day

If we haven’t made any mistakes or incorrect assumptions then we could say that receiving 262mg/day will not harm you. OSHA’s TWA # is to be read as, less than X is safe. It is not to be read as, more than X will harm you. OSHA’s LD₅₀ is the, this will kill 50% of people exposed number. LD₅₀ for an 81kg person is 1600g in a single dose. Two important points to consider, OSHA is conservative with it’s numbers and I have no idea how they came up with a TWA of 10mg/m³

I don’t know much about the WHO (not the band ) but their # seems to be for injected or eaten PG which would not indicate the effects on the lungs due to inhalation.

Crunching the numbers is fun but until someone does some real research on PV’s, it’s all just guesswork.

[cdog2008]

ok this hole Vg Pg safe thing is unbelievable, pg is much safer than vg just do some research, be creative, google propylene glycol in nebulizers and you will see it is used for breathing machines, not all drugs use it but it clearly states it is used in nebulizers, that should tell you something, also go to DOW the leading maker of PG and see it is used in the medical field, im not saying VG isnt safe, but its tested safe for digestion and no tests i could find say its safe for inhalation, so in my personal opinion im not gonna be the lab rat for inhaling vegetable oil in my lungs, i would rather trust something the medical field and the FDA use and say safe, so on that note im saying PG all the way and ill take my chances on 1 ingredient and save my self from the 3000+ chemicals and now carpet glue added to the list so it puts itself out if left in an ashtray, so come on people weigh it out 1 sterile ingredient or 3000+ un sterile ingredients in analogs.. another thing that irritates me is prob 100% of people on this site smoke or did smoke analogs and wernt to concerned about how bad analogs are when they smoked and all the chemicals in them, but god forbid we smoke one chemical from an e-cig and people are all the sudden concerned about what they put in there lungs. think about it, if people are worried about it go back to analogs and kill your selves. do a search on the chemicals in an analog and then go throw up you will be shocked

[satoshi]

ok this hole Vg Pg safe thing is unbelievable, pg is much safer than vg just do some research, be creative, google propylene glycol in nebulizers and you will see it is used for breathing machines, not all drugs use it but it clearly states it is used in nebulizers, that should tell you something, also go to DOW the leading maker of PG and see it is used in the medical field, im not saying VG isnt safe, but its tested safe for digestion and no tests i could find say its safe for inhalation, so in my personal opinion im not gonna be the lab rat for inhaling vegetable oil in my lungs, i would rather trust something the medical field and the FDA use and say safe, so on that note im saying PG all the way and ill take my chances on 1 ingredient and save my self from the 3000+ chemicals and now carpet glue added to the list so it puts itself out if left in an ashtray, so come on people weigh it out 1 sterile ingredient or 3000+ un sterile ingredients in analogs.. another thing that irritates me is prob 100% of people on this site smoke or did smoke analogs and wernt to concerned about how bad analogs are when they smoked and all the chemicals in them, but god forbid we smoke one chemical from an e-cig and people are all the sudden concerned about what they put in there lungs. think about it, if people are worried about it go back to analogs and kill your selves. do a search on the chemicals in an analog and then go throw up you will be shocked

But it's not like the only two choices in life are smoking analogs or smoking e-cigs. There are snus, NRT, ariva/stonewall dissolvables, etc. to still get the nicotine fix, if someone's not going to give that up.

[leannebug]

I haven't read the whole thread yet, so I don't know if this one has been posted...
I stumbled across this while searching for something else. Thought it might be noteworthy.

Pet Food and Treat Ingredient Propylene Glycol

[underwater goddess]

Kinda random, but...

Several of the types of bread at Subway contain large amounts (it was near the top of the list) of PG.

(I have allergies, so I read labels before eating anything)