Impurities in isopropanol sold as electronics cleaner?

A

Adam Funk

Guest
In the US, it's fairly easy to find 70% isopropanol sold for use as a
topical antiseptic & such. In the UK, it's harder to find, but I can
buy "100%" isopropanol as electronics cleaner & dilute it to 70%.
Does anyone know if the latter is likely to contain traces of
dangerous impurities that make it unsuitable for topical antiseptic
use, sterilizing electric toothbrush heads, etc.?

(I'm aware of the traces of benzene in "nearly 100%" industrial
ethanol that make it dangerous; that's what set me on this train of
thought.)



--
There's a statute of limitations with the law, but not with
your wife. --- Ray Magliozzi, Car Talk 2011-36
 
On 12/05/2016 08:58 AM, Adam Funk wrote:
In the US, it's fairly easy to find 70% isopropanol sold for use as a
topical antiseptic & such. In the UK, it's harder to find, but I can
buy "100%" isopropanol as electronics cleaner & dilute it to 70%.
Does anyone know if the latter is likely to contain traces of
dangerous impurities that make it unsuitable for topical antiseptic
use, sterilizing electric toothbrush heads, etc.?

(I'm aware of the traces of benzene in "nearly 100%" industrial
ethanol that make it dangerous; that's what set me on this train of
thought.)
Click to expand...
IIRC nowadays ethanol is denatured with kerosene, not benzene, at least
over here.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics

160 North State Road #203
Briarcliff Manor NY 10510

hobbs at electrooptical dot net
http://electrooptical.net
 
On Mon, 05 Dec 2016 11:31:44 -0500, Phil Hobbs wrote:

On 12/05/2016 08:58 AM, Adam Funk wrote:
In the US, it's fairly easy to find 70% isopropanol sold for use as a
topical antiseptic & such. In the UK, it's harder to find, but I can
buy "100%" isopropanol as electronics cleaner & dilute it to 70%. Does
anyone know if the latter is likely to contain traces of dangerous
impurities that make it unsuitable for topical antiseptic use,
sterilizing electric toothbrush heads, etc.?

(I'm aware of the traces of benzene in "nearly 100%" industrial ethanol
that make it dangerous; that's what set me on this train of thought.)



IIRC nowadays ethanol is denatured with kerosene, not benzene, at least
over here.
Click to expand...

It's not that. Simple distillation of ethanol in water can't get you a
stronger concentration of ethanol than 95.6% (search on "azeotrope" for
the full info). Getting ethanol closer to 100% requires some process
that involves benzine, but other than the fact that there's residual
benzine in the fire-water, I have no idea what that process is.

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

I'm looking for work -- see my website!
 
On Tuesday, December 6, 2016 at 9:25:15 AM UTC-5, Phil Hobbs wrote:
On 12/05/2016 03:36 PM, Tim Wescott wrote:
On Mon, 05 Dec 2016 11:31:44 -0500, Phil Hobbs wrote:

On 12/05/2016 08:58 AM, Adam Funk wrote:
In the US, it's fairly easy to find 70% isopropanol sold for use as a
topical antiseptic & such. In the UK, it's harder to find, but I can
buy "100%" isopropanol as electronics cleaner & dilute it to 70%. Does
anyone know if the latter is likely to contain traces of dangerous
impurities that make it unsuitable for topical antiseptic use,
sterilizing electric toothbrush heads, etc.?

(I'm aware of the traces of benzene in "nearly 100%" industrial ethanol
that make it dangerous; that's what set me on this train of thought.)



IIRC nowadays ethanol is denatured with kerosene, not benzene, at least
over here.

It's not that. Simple distillation of ethanol in water can't get you a
stronger concentration of ethanol than 95.6% (search on "azeotrope" for
the full info). Getting ethanol closer to 100% requires some process
that involves benzine, but other than the fact that there's residual
benzine in the fire-water, I have no idea what that process is.


I know about the 190 proof problem. ;) Whether there's benzene depends
on the feed stock, though. Grain neutral spirit doesn't have benzene in
any significant quantity AFAICT.

Even if it did, the actual amount of benzene that's going to be lurking
in the OP's toothbrush after it dries would be trivial.

IIRC denatured ethanol used to have benzene added intentionally, before
it was discovered to be seriously carcinogenic, at which point they
switched to kerosene.

A quick web search reveals that you can dry ethanol by vacuum
evaporation (the azeotrope doesn't form below about 70 torr), by
reaction with quicklime (CaO), or by sequestration using molecular
sieves. Even tapioca works, apparently.
https://www.purdue.edu/newsroom/research/2011/110913LadischTapioca.html> !
Click to expand...

Hmm and apparently you "dry out" IPA with salt.
https://www.youtube.com/watch?v=mEFhMfaT-vg
(Kinda cool to watch the phase separation, I wonder how long it takes?)

George H.
Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics

160 North State Road #203
Briarcliff Manor NY 10510

hobbs at electrooptical dot net
http://electrooptical.net
Click to expand...
 
On Tuesday, December 6, 2016 at 11:30:07 AM UTC-5, Adam Funk wrote:
On 2016-12-05, Tim Wescott wrote:

On Mon, 05 Dec 2016 11:31:44 -0500, Phil Hobbs wrote:

On 12/05/2016 08:58 AM, Adam Funk wrote:
In the US, it's fairly easy to find 70% isopropanol sold for use as a
topical antiseptic & such. In the UK, it's harder to find, but I can
buy "100%" isopropanol as electronics cleaner & dilute it to 70%. Does
anyone know if the latter is likely to contain traces of dangerous
impurities that make it unsuitable for topical antiseptic use,
sterilizing electric toothbrush heads, etc.?

(I'm aware of the traces of benzene in "nearly 100%" industrial ethanol
that make it dangerous; that's what set me on this train of thought.)



IIRC nowadays ethanol is denatured with kerosene, not benzene, at least
over here.

It's not that. Simple distillation of ethanol in water can't get you a
stronger concentration of ethanol than 95.6% (search on "azeotrope" for
the full info). Getting ethanol closer to 100% requires some process
that involves benzine, but other than the fact that there's residual
benzine in the fire-water, I have no idea what that process is.

Yeah, I know about that!
What about the isopropanol?!?
Google is your friend. (it's 91%... which is what we buy for cleaning.)
Click to expand...

George H.
--
Thinking about her this morning, lying in bed, and trying to get my
thoughts on the right track, I reached into the drawer of the bedstand,
and found the Gideons' Bible, and I was going for the Psalms, friend, honest
I was, but I found the Song of Solomon instead. --- Garrison Keillor
Click to expand...
 
On 12/05/2016 03:36 PM, Tim Wescott wrote:
On Mon, 05 Dec 2016 11:31:44 -0500, Phil Hobbs wrote:

On 12/05/2016 08:58 AM, Adam Funk wrote:
In the US, it's fairly easy to find 70% isopropanol sold for use as a
topical antiseptic & such. In the UK, it's harder to find, but I can
buy "100%" isopropanol as electronics cleaner & dilute it to 70%. Does
anyone know if the latter is likely to contain traces of dangerous
impurities that make it unsuitable for topical antiseptic use,
sterilizing electric toothbrush heads, etc.?

(I'm aware of the traces of benzene in "nearly 100%" industrial ethanol
that make it dangerous; that's what set me on this train of thought.)



IIRC nowadays ethanol is denatured with kerosene, not benzene, at least
over here.

It's not that. Simple distillation of ethanol in water can't get you a
stronger concentration of ethanol than 95.6% (search on "azeotrope" for
the full info). Getting ethanol closer to 100% requires some process
that involves benzine, but other than the fact that there's residual
benzine in the fire-water, I have no idea what that process is.
Click to expand...

I know about the 190 proof problem. ;) Whether there's benzene depends
on the feed stock, though. Grain neutral spirit doesn't have benzene in
any significant quantity AFAICT.

Even if it did, the actual amount of benzene that's going to be lurking
in the OP's toothbrush after it dries would be trivial.

IIRC denatured ethanol used to have benzene added intentionally, before
it was discovered to be seriously carcinogenic, at which point they
switched to kerosene.

A quick web search reveals that you can dry ethanol by vacuum
evaporation (the azeotrope doesn't form below about 70 torr), by
reaction with quicklime (CaO), or by sequestration using molecular
sieves. Even tapioca works, apparently.
<https://www.purdue.edu/newsroom/research/2011/110913LadischTapioca.html> !

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics

160 North State Road #203
Briarcliff Manor NY 10510

hobbs at electrooptical dot net
http://electrooptical.net
 
On 2016-12-05, Tim Wescott wrote:

On Mon, 05 Dec 2016 11:31:44 -0500, Phil Hobbs wrote:

On 12/05/2016 08:58 AM, Adam Funk wrote:
In the US, it's fairly easy to find 70% isopropanol sold for use as a
topical antiseptic & such. In the UK, it's harder to find, but I can
buy "100%" isopropanol as electronics cleaner & dilute it to 70%. Does
anyone know if the latter is likely to contain traces of dangerous
impurities that make it unsuitable for topical antiseptic use,
sterilizing electric toothbrush heads, etc.?

(I'm aware of the traces of benzene in "nearly 100%" industrial ethanol
that make it dangerous; that's what set me on this train of thought.)



IIRC nowadays ethanol is denatured with kerosene, not benzene, at least
over here.

It's not that. Simple distillation of ethanol in water can't get you a
stronger concentration of ethanol than 95.6% (search on "azeotrope" for
the full info). Getting ethanol closer to 100% requires some process
that involves benzine, but other than the fact that there's residual
benzine in the fire-water, I have no idea what that process is.
Click to expand...

Yeah, I know about that!
What about the isopropanol?!?


--
Thinking about her this morning, lying in bed, and trying to get my
thoughts on the right track, I reached into the drawer of the bedstand,
and found the Gideons' Bible, and I was going for the Psalms, friend, honest
I was, but I found the Song of Solomon instead. --- Garrison Keillor
 
On Friday, December 23, 2016 at 7:00:06 AM UTC-5, Adam Funk wrote:
On 2016-12-06, George Herold wrote:

On Tuesday, December 6, 2016 at 11:30:07 AM UTC-5, Adam Funk wrote:

Yeah, I know about that!
What about the isopropanol?!?

Google is your friend. (it's 91%... which is what we buy for cleaning.)

Actually the data sheet for the stuff I've bought says 99.7%, and it
just has warnings for flammability, eye irritation, & "may cause
drowsiness or dizziness".

http://uk.rs-online.com/web/p/precision-cleaners-degreasers/0448180/

http://docs-europe.electrocomponents.com/webdocs/0b4e/0900766b80b4ef3d.pdf

http://docs-europe.electrocomponents.com/webdocs/001e/0900766b8001ed5e.pdf
Click to expand...
Keep the cap tight. I think it will suck water out of the air till it
reaches 91%.

George H.
--
There’s never enough time to do all the nothing you want.
--- Calvin
Click to expand...
 
On 2016-12-06, George Herold wrote:

On Tuesday, December 6, 2016 at 11:30:07 AM UTC-5, Adam Funk wrote:

Yeah, I know about that!
What about the isopropanol?!?

Google is your friend. (it's 91%... which is what we buy for cleaning.)
Click to expand...

Actually the data sheet for the stuff I've bought says 99.7%, and it
just has warnings for flammability, eye irritation, & "may cause
drowsiness or dizziness".

<http://uk.rs-online.com/web/p/precision-cleaners-degreasers/0448180/>

<http://docs-europe.electrocomponents.com/webdocs/0b4e/0900766b80b4ef3d.pdf>

<http://docs-europe.electrocomponents.com/webdocs/001e/0900766b8001ed5e.pdf>


--
There’s never enough time to do all the nothing you want.
--- Calvin
 
On 2016-12-23, George Herold wrote:

On Friday, December 23, 2016 at 7:00:06 AM UTC-5, Adam Funk wrote:
On 2016-12-06, George Herold wrote:

On Tuesday, December 6, 2016 at 11:30:07 AM UTC-5, Adam Funk wrote:

Yeah, I know about that!
What about the isopropanol?!?

Google is your friend. (it's 91%... which is what we buy for cleaning.)

Actually the data sheet for the stuff I've bought says 99.7%, and it
just has warnings for flammability, eye irritation, & "may cause
drowsiness or dizziness".

http://uk.rs-online.com/web/p/precision-cleaners-degreasers/0448180/

http://docs-europe.electrocomponents.com/webdocs/0b4e/0900766b80b4ef3d.pdf

http://docs-europe.electrocomponents.com/webdocs/001e/0900766b8001ed5e.pdf


Keep the cap tight. I think it will suck water out of the air till it
reaches 91%.
Click to expand...

I do anyway, but it doesn't hurt to remind people.


--
Some people just have hatred built into them. I don’t know if there
is anything we can do for them... The right wingers of our country
might just have bad genetics. And I’m saying that as a transvestite.
--- Eddie Izzard
 
On Wed, 04 Jan 2017 12:16:52 +0000, Adam Funk <a24061@ducksburg.com>
quoted:

Some people just have hatred built into them. I don’t know if there
is anything we can do for them... The right wingers of our country
might just have bad genetics. And I’m saying that as a transvestite.
--- Eddie Izzard
Click to expand...

The tag line says it all...

...Jim Thompson
--
| James E.Thompson | mens |
| Analog Innovations | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| STV, Queen Creek, AZ 85142 Skype: skypeanalog | |
| Voice:(480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |

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