Naked Science Forum

Life Sciences => Physiology & Medicine => Topic started by: set fair on 09/12/2018 14:26:58

Title: What happened to propylene glycol in hospital air conditioning?
Post by: set fair on 09/12/2018 14:26:58: Putting propylene glycol in hospital air conditioning was fairly common around the middle of the last century. It acted as a bactericide - presumed to dehydrate the bacteria, although I haven't found any reference to evidence that this was how it works.

Is it still used? With growing antibiotic resistance is it time to start using it again?
Title: Re: What happened to propylene glycol in hospital air conditioning?
Post by: chris on 10/12/2018 06:49:50: I was not aware of this; do you have a reference?

Just speculating here, but hospital water supplies and aircon systems have come under a lot of scrutiny in recent years with respect to entities like Legionella; changes in policy and practice may well have come in the wake of this.
Title: Re: What happened to propylene glycol in hospital air conditioning?
Post by: Colin2B on 10/12/2018 07:56:59: I have seen reference to it being used in air conditioning systems as an antifreeze where ethylene glycol is considered too dangerous to use in case of leak eg food processing/storage. Never come across it being put into the air itself.
Title: Re: What happened to propylene glycol in hospital air conditioning?
Post by: set fair on 10/12/2018 20:39:20: Quote from: chris on 10/12/2018 06:49:50
I was not aware of this; do you have a reference?

https://www.jpeds.com/article/S0022-3476(42)80046-3/abstract
Title: Re: What happened to propylene glycol in hospital air conditioning?
Post by: set fair on 10/12/2018 20:40:58: try again https://www.jpeds.com/article/S0022-3476(42)80046-3/abstract
Title: Re: What happened to propylene glycol in hospital air conditioning?
Post by: RD on 10/12/2018 23:06:59: Quote from: Colin2B on 10/12/2018 07:56:59
... Never come across it being put into the air itself.

Apparently it's in e-cigs ... https://www.sciencedirect.com/science/article/pii/S0278691517305112

[and its (acidic) breakdown products will corrode metal (refrigeration) pipes].
Title: Re: What happened to propylene glycol in hospital air conditioning?
Post by: Colin2B on 10/12/2018 23:42:42: Quote from: RD on 10/12/2018 23:06:59
Apparently it's in e-cigs ...
Yes, I found that a short while ago when looking to see if there were any side effects to inhaling the vapour. CDC has a whole paper on it.
Not sure I would want to inhale something that corrodes refrigeration pipes!
Title: Re: What happened to propylene glycol in hospital air conditioning?
Post by: Bored chemist on 11/12/2018 07:25:49: Quote from: Colin2B on 10/12/2018 23:42:42
Quote from: RD on 10/12/2018 23:06:59
Apparently it's in e-cigs ...
Yes, I found that a short while ago when looking to see if there were any side effects to inhaling the vapour. CDC has a whole paper on it.
Not sure I would want to inhale something that corrodes refrigeration pipes!
I'm OK with inhaling oxygen and water.

I wonder if glycol still gets used as an air conditioner or if it has been replaced by systems that rely on cooling to strip excess humidity.
Title: Re: What happened to propylene glycol in hospital air conditioning?
Post by: Colin2B on 11/12/2018 08:27:05: Quote from: Bored chemist on 11/12/2018 07:25:49
I'm OK with inhaling oxygen and water.
Good point ;D
Still not keen on glycol
Quote from: Bored chemist on 11/12/2018 07:25:49
I wonder if glycol still gets used as an air conditioner or if it has been replaced by systems that rely on cooling to strip excess humidity.
I thought it’s main use was in the air conditioning cooling water as an antifreeze, rather than as an ‘air conditioner’.