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Killing yourself with solvents (Alcohols and Hydrocarbons I have loved)

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helius:

--- Quote from: Cerebus on May 13, 2020, 01:10:01 am ---I was a great fan of Trichlorethylene and was rather miffed when it went the way of all flesh because of new regulations about chlorinated solvents. Nothing beat it as degreasing agent without being either very much more flammable or much more toxic.
--- End quote ---
Trichloroethylene is still available: I have a can of it in my paint drawer (Sprayon EL848). It was manufactured just three years ago. What got banned by the Montreal Protocol was 1,1,1-trichloroethane, because it is an ozone depleter. 1,1,1-trichloroethane was not regulated for health reasons.


--- Quote ---The toxicity profile of Trichlorethylene was actually very good, the only real drawback was that it was quite possible to knock yourself out with it if you were stupid enough to use something so volatile in an unventilated space - it's chemically very closely related to Halothane (2-Bromo-2-chloro-1,1,1-trifluoroethane) which is an inhalational anaesthetic.
--- End quote ---
Now I'm quite certain you have mixed up trichloroethylene with 1,1,1-trichloroethane. Trichloroethylene or "TCE" is a particularly toxic solvent whose dangers became evident in the 1960s when it began to be found in groundwater around IBM's disk drive factories in Santa Clara, CA. It was largely replaced for aerosol uses by 1,1,1-trichloroethane ("Tric"), which was much less toxic. However, 1,1,1-trichloroethane is an ozone depleter and was banned in the late 1990s under the Montreal Protocol that regulated CFCs.


--- Quote ---Carbon Tet. was all over the place back in the day. Used to be used by dry cleaners until somebody finally got the memo that it was rather more than just a suspected carcinogen. Replaced in dry cleaning with Trichlorethylene. I always associate the smell of Trichlorethylene and with libraries, there was a dry cleaners smack next to the main library where I grew up and there was always a lingering smell of it in the area.

--- End quote ---
Dry cleaning solvent is almost entirely perchloroethylene (tetrachloroethylene). It is also widely available (maybe not in Los Angeles) as aerosol brake cleaner. My understanding is that perchloroethylene is much less toxic compared to trichloroethylene or trans-1,2-dichloroethylene.

These days cleaners are increasingly switching to "organic" (sheesh) clothes cleaning methods including D5 cyclomethicone, or "wet cleaning" using new equipment.

I saw some 60% carbon tetrachloride in an old fire extinguisher. Looked like it was still full. Great stuff I'm sure.

As far as methylated spirits/denatured alcohol goes;
I believe the ratio of ethanol:methanol is 10:1 or more, which makes it less dangerous to contact the skin. The reason for this is that ethanol and methanol compete for the same enzyme, alcohol dehydrogenase. Ethanol gets metabolized by this enzyme to acetaldehyde (the cause of hangovers), whle methanol gets metabolized to formaldehyde (a neurotoxin and cell destroyer). If the active site of the enzyme always bumps into an ethanol molecule, it can't metabolize methanol, which is why the treatment for methanol poisoning is high doses of ethanol.
It is still not a good idea to intentionally put it on the skin.


--- Quote from: MK14 ---If you don't mind me asking, where do you get your supply of Limonene from ?
--- End quote ---
The products I am familiar with are Citra-Solv and De-Solv-It. Note that many cleaners such as Simple Green also contain glycol ethers in addition to limonene.

Cerebus:

--- Quote from: MK14 on May 13, 2020, 02:39:56 am ---
--- Quote from: Cerebus on May 13, 2020, 02:30:55 am ---I keep a spray bottle of limonene

--- End quote ---

If you don't mind me asking, where do you get your supply of Limonene from ?
I recently tried ebay, but it seems fairly expensive, for a bottle with not much in it.
D-Limonene Citrus/Orange Turpene 250ml 100%, for £8.99, seller jamalmiah.

--- End quote ---

Off of eBay UK (I'll look for the vendor in a minute, but it's long enough ago that it's probably fallen off my purchase history). I got a litre for a sensible price - which with me being a cheapskate probably equates to 'cheap' to most people. I don't have the original HDPE bottle that it was supplied in (decanted it into a proper reagent bottle) so I can't find the vendor's name that way. My usual eBay vendor for solvents and the like is apcpure (http://www.ebaystores.co.uk/apcpure) so it was probably them, but they don't have any at the moment.

Hold on .... Nope,  - I was right, too long ago. On searching it does seem prices are crazy high at the moment. You might need to wait for the world to return to something like normality before prices go back to normal.

drussell:

--- Quote from: helius on May 13, 2020, 05:17:48 pm ---Now I'm quite certain you have mixed up trichloroethylene with 1,1,1-trichloroethane.
...
Dry cleaning solvent is almost entirely perchloroethylene (tetrachloroethylene). It is also widely available (maybe not in Los Angeles) as aerosol brake cleaner. My understanding is that perchloroethylene is much less toxic compared to trichloroethylene or trans-1,2-dichloroethylene.
--- End quote ---

Oh, wait...  I misread this all initially also and am incorrect.

The 75089 Brakleen I have here is perchloroethylene / tetrachloroethylene.

Yes, the same as the dry cleaning solvent.  It is handy for that kind of oily stain removal....

drussell:

--- Quote from: helius on May 13, 2020, 05:17:48 pm ---I saw some 60% carbon tetrachloride in an old fire extinguisher. Looked like it was still full. Great stuff I'm sure.
--- End quote ---

Here's a video of an Aussie bloke making a bit of a mess trying to get some out...  :)



Cerebus:

--- Quote from: helius on May 13, 2020, 05:17:48 pm ---Now I'm quite certain you have mixed up trichloroethylene with 1,1,1-trichloroethane.

--- End quote ---

What I was confusing was my spelling (which always happens with me with alkanes, alkenes, et. al.). You are right, I did mean trichloroethane. In my defence, I was just copying the existing misspelling perpetrated by another because the Servisol referred to before was most definitely 1,1,1-trichloroethane. I was thinking about the right thing but writing about the wrong one. As I say, not the first time I've done that with the whole alkane/alkene/alkyne thing.


--- Quote ---
--- Quote ---Carbon Tet. was all over the place back in the day. Used to be used by dry cleaners until somebody finally got the memo that it was rather more than just a suspected carcinogen. Replaced in dry cleaning with Trichlorethylene. I always associate the smell of Trichlorethylene and with libraries, there was a dry cleaners smack next to the main library where I grew up and there was always a lingering smell of it in the area.

--- End quote ---
Dry cleaning solvent is almost entirely perchloroethylene (tetrachloroethylene).

--- End quote ---

I was thinking back to the 60s when Carbon Tet. was replaced with thichlorethane in the UK (under the tradename Trilene (my spelling of that may be off)) and was then subsequently replaced with perchorethylene.


--- Quote ---I saw some 60% carbon tetrachloride in an old fire extinguisher. Looked like it was still full. Great stuff I'm sure.

--- End quote ---

We had one of those - a brass 'syringe' affair that my Father dug up from somewhere. He was rapidly dissuaded from putting it on the wall in the kitchen by both my mother (a chemist) and me.


--- Quote ---As far as methylated spirits/denatured alcohol goes;
I believe the ratio of ethanol:methanol is 10:1 or more, which makes it less dangerous to contact the skin. The reason for this is that ethanol and methanol compete for the same enzyme, alcohol dehydogenase. Ethanol gets metabolized by this enzyme to acetaldehyde (the cause of hangovers), whle methanol gets metabolized to formaldehyde (a neurotoxin and cell destroyer). If the active site of the enzyme always bumps into an ethanol molecule, it can't metabolize methanol, which is why the treatment for methanol poisoning is high doses of ethanol.
It is still not a good idea to intentionally put it on the skin.

--- End quote ---

Really it's not much of an issue putting any of these on your skin as long as you don't bathe in them. The whole point of all these skin sanitisers using alcohols of one sort or another is that the alcohol used is toxic, if it wasn't it wouldn't kill off the things it's supposed to kill off.

LD50 (skin) for Methanol is 15.8g/kg (rabbit), Isopropanol > 10g/kg (rabbit) and Ethanol 15.8g/kg (rabbit); so methanol is no worse a toxin for skin contact than good old ethanol. This shouldn't be a surprise because the mechanism of transfer across the skin to where it can exercise any toxicity is going to be similar, if not probably identical, for all three alcohols. The skin is evolved to be a barrier and does a very good job of that, you have to get through quite a layer of no longer living material before you can get to the living stuff to do it any harm.

On a side note, ADH actually preferentially binds to ethanol over methanol.

The formulae used around the world for denatured alcohol vary quite a lot. Only some contain methanol, many contain other denaturants either alone or in combination with methanol. I'd have more concern about some of the other denaturants used in terms of through-skin toxicity than I would have about methanol per se. A common addition is methyl ethyl ketone, which has an LD50 (skin) of 5g/kg (rabbit) and because of its affinity for and high solubility in lipids it can do a much better job of crossing the skin's barrier.

The official formulation for "completely denatured alcohol" in the UK is


--- Quote from: https://www.gov.uk/government/publications/excise-notice-473-production-distribution-and-use-of-denatured-alcohol/excise-notice-473-production-distribution-and-use-of-denatured-alcohol#section16 ---Per hectolitre of absolute ethanol:

    1 litre of isopropyl alcohol
    1 litre of methyl ethyl ketone
    1 gram of denatonium benzoate


--- End quote ---
(There are other formulae in common use in the EU at that URL)

So "methylated spirits" may actually not contain any methanol nowadays.

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