PG has anti-bacterial properties

[Deleted]

I was recently telling someone that I haven't had a single cold or sniffle since I started vaping.

This is probably the reason why:
www.ncbi.nlm.nih.gov/pmc/articles/PMC2135271/

Concentrations of 1 gm. of propylene glycol vapor in two to four million cc. of air produced immediate and complete sterilization of air into which pneumococci, streptococci, staphylococci, H. influenzae, and other microorganisms as well as influenza virus had been sprayed. With lesser concentrations of propylene glycol, rapid and marked reduction in the number of air-borne bacteria occurred, but complete sterilization of the air required a certain interval of time.

So PG kills all sorts of nasties. 
Now.......if they pumped that around hospitals........ 

[cheekiecharlie]

they do ,its been used in hospitals for years ,kills bacteria in the ventilation systems afaik

[*-SARIN-*]

Yep that'll be due to it's two alcohol functional groups

[chykensa]

You tease, *-SARIN-*, you leave is hanging in the air with your talk of 'alcohol functional groups', without telling us what they are and what they do! You chemists are all the same

[yahoo2u2]

All the info you will ever need

www.evidence.nhs.uk/search?q=Propylene%20glycol

[sydsut]

Jan 13, 2016 23:06:36 GMT *-SARIN-* said:

Yep that'll be due to it's two alcohol functional groups

I'm part of the alcohol dis-functional group

[monty]

It also kills air borne viruses. There are references to the action being due to its dehydrating properties and these references go back decades. But I have never seen a reference to a clinical study demonstrating that dehydration is how PG kills germs so it may not be true or it may not be the whole story.

Jan 13, 2016 23:06:36 GMT *-SARIN-* said:

Yep that'll be due to it's two alcohol functional groups

Have you any references to back this up? Ethanol (ethyl alcohol, the active ingredient in booze) as a liquid can be used to sterilize but not liquid PG.

[nanotm]

Jan 13, 2016 22:33:14 GMT cheekiecharlie said:

they do ,its been used in hospitals for years ,kills bacteria in the ventilation systems afaik

a lot of hospitals stpped using it about a decade ago and moved over to some less effective option or just stopped completely because so many people were exhibiting mild reactions to it .... which is why things like norovirus spread like wildfire in most hospitals but barely make it across the ward in others ....

as has been proven a mild antihistamine taken for the first week of exposure will void the effects in most people, but studies haven't been done so this is anecdotal science not real science .....

[*-SARIN-*]

Jan 14, 2016 11:02:57 GMT monty said:

It also kills air borne viruses. There are references to the action being due to its dehydrating properties and these references go back decades. But I have never seen a reference to a clinical study demonstrating that dehydration is how PG kills germs so it may not be true or it may not be the whole story.

Jan 13, 2016 23:06:36 GMT *-SARIN-* said:

Yep that'll be due to it's two alcohol functional groups

Have you any references to back this up? Ethanol (ethyl alcohol, the active ingredient in booze) as a liquid can be used to sterilize but not liquid PG.

No references required, alcohol is a known anti-bacterial agent (think of the wipes and sprays on the market) and i will try to explain in laymans terms but we first have to understand some basic chemistry.  Alcohol as a word is rather vast and in the chemical world it means an substance containing an alcohol functional group(-OH) consisting of an oxygen (O) and a hydrogen atom (H).  PG being a "diol" contains two alcohol functional groups (see figure 1).
Figure 1:


 
How does it kill bacteria?

Alcohol kills bacteria because it breaks down its cell wall and membranes which in turn allows enables it easier access to denature the bacteria's proteins, causing it to "die"

Does the % volume of the alcohol make a difference?

Yes it does.  Typical anti-bacterial / anti-septic sprays and wipes contain no more than 70% alcohol, with the rest of the volume made up of water.  A few reasons for this:

1)  It will evaporate too quickly at higher % volume.
2)  Some water is required to enable the alcohol to penetrate the cell membranes.  100% alcohol coagulates the cell proteins quickly and stops it reaching further into the cell to denature the rest.
3)  Greater % volume costs more money.

Does PG kill bacteria by dehydrating?

No because the alcohol in it isn't in a great enough volume.  PG kills bacteria using the denaturing of protein method described above albeit very slowly.

Is PG effective as an anti-bacterial agent?

Yes and no depending on the circumstances, it has anti-bacterial properties but there are better products on the market.

Why use it in air conditioning systems then?

Again a few answers:

1)  It's cheap.
2)  It's stable within the temperature ranges of air conditioning units.
3)  Air conditioning units are notorious for moving air about and mixed with a nice temperature for bacteria to thrive it helps combat this.

Why isn't PG used to sterilise operating equipment and tools?

Because quicker acting and more effective substances on the market.

Can whiskey or any other spirit be used to clean a wound of bacteria and prevent infection?

Yes but don't swill it and spit it on the wound, you will be introducing nasties from your mouth into the wound, just pour it.  Better still don't bother and go to the hospital sharpish.


Hey, why don't i get any gunky minging green fuzzy shit in my e-liquid bottles or tanks?

Re-read the above


I've sat mesmerised at the feeling i get when i pour isopropyl alcohol (IPA) or acetone (nail varnish remover) on my hands, why does it happen?

That is the cooling effect of the substance rapidly evaporating and withdrawing heat away from your skin.  It's dangerous, don't do it, they both readily penetrate the skin and hit the Central Nervous System (CNS).  The CNS will then have a meltdown and if it is IPA, make you very wobbly  On a more serious not, this rapid evaporation and it's effects is why IPA isn't used in air conditioning systems.


If PG contains alcohol functional groups can i drink it to get pissed?

No, just no, stupid boy!

========================================================================================================================

That's the basics of what it does and has hopefully answered the questions above, i suspect though that it might raise more.  We're just hitting the realms of A-level organic chemistry here and already it's getting complicated to put it down in words.  Don't even ask about primary, secondary or tertiary alcohols!


***Next week we will learn how to make home made diamonds from pencils.***

[gill2009]

I found that really interesting *-SARIN-*...thank you for taking the time to post it all 

[taz96]

*-SARIN-* Thank you, I actually understood that.

[Deleted]

yes yes *-SARIN-* thats all well and good BUT
how do we make them there diamonds i been out and got my new pencils dam i'm all ready set up and waiting to go thinking smiley

But thank you for writing that in a way even a dumb arse like me could understand ( well most of it )

[lisburnvapes]

Dunno about the rest of you's but I think it's pretty cool having our own resident chemist ! Cheers *-SARIN-*

[letsavit]

Well after today's lesson by *-SARIN-* I can add they don't use it in hospitals, just water via a humidifier. They do spec larger volumes of extract and supply over a normal building and the exhaust (air being removed from the building) has to be further apart from inlet (the fresh air) being pulled in. Other than medical gases and a more back up from a power cut via a battery room and generators it's the same as an office block.

[chykensa]

Thank you *-SARIN-*, as a non-scientist that was refreshingly easy to read and understand. Could you please explain how I can distill my own alcohol from potato peelings so that i can keep the bank manager at bay for the rest of January?
Seriously, really well written and comprehensible, it is indeed great to have a knowledgeable chemist in our midst