Thursday, July 17, 2008

Methylene chloride

I've always wondered and now I am asking the world: Why does methylene chloride hurt when I get it on my skin? It's especially bad under a ring.

Here's another question, what is your preferred name for CH2Cl2?

18 comments:

Jons said...

I tend to call it DCM, but I have a special love for acronyms.

Whenever I've spilled it on myself I always get a blistery rash, which makes me think I have a sensitivity to it.

Ψ*Ψ said...

DCM!
I've always wondered that too. Hopefully someone out there knows.

Chemgeek said...

So far 100% DCM.

I gotta be honest, I never heard the use of 'DCM' to refer to dichloromethane until about 7 years into my chemistry career. I know, that's weird. I'm a little freaked out myself.

milkshake said...

DCM and chloroform have this thing - they are both irritating on their own but the problem gets far, far worse if they contain traces of HCl: because that acid - diluted as it might be - soaks right into your skin. You may want to treat it as organic acid burn, with neat ethanolamine for half a minute then wash away thoroughly, the hurt should go away promptly.

Dont try old chloroform sprinkle into your eyes - it is one of the most painful things I experienced (and you cannot use ethanolamine there)

Also, anhydrous HCl in dioxane is extremely unpleasant on your hands.

Maybe you should check what kind of DCM grade you are using - try it on wet pH paper, to see if it goes pink. Since we started using olefin-stabilised DCM, HPLC grade, we rarely have the "caustic DCM" problem anymore.

the indefatigable mjenks said...

I didn't start calling it DCM until I got into industry and surrounded by other lazy chemists.

Up through and including grad school, it was methylene chloride.

I've never understood as to why it burns so badly under the ring. Maybe Sauron blew up and became DCM, and he's trying to get it back.

Leave it to me to LOTR-ize a perfectly fine chemistry post. :D

milkshake said...

it butns under the ring because it cannot evaporate there as easily - so the exposure is longer and in fact the acid will concentrate there. You can get the same "enhanced burning" if you dip your shirt sleeve in it

the indefatigable mjenks said...

I guess that explains why it hurts more when you let it soak through the gloves.

By the way...nitrile gloves don't stop it.

Chemgeek said...

Milkshake: Thanks. That makes sense. As for the grade, my most recent use was for stripping the varnish off a table. The small drop of varnish remover I got on my arm was very painful. I'm sure this is the lowest grade available, not to mention the other stuff mixed with it.

Matt: LOTR-ize anytime.

Liberal Arts Chemist said...

Eschew acronymns and non-informative common names in the lab. Confusion is the rock under which the troll of danger lurks.

No, it MUST be called lovingly by its full name:

Dichloro-Meethane (trained by ex-patriot Brits, spent time in the UK).

As for why it hurts I don't know but I do know that it's the only solvent I've found that will efficiently strip silicon grease off a ground glass joint.

Chemgeek said...

"Meethane"

I have always loved that pronunciation.

Anonymous said...

Although think milkshake is correct about possible traces of HCl I thought DCM "dehydrates" skin as absorbs into fats/proteins repelling H2O and breaking up tissue structure thus triggering nerve responses.

Get a Brit to "ligand".

Chemgeek said...

I don't know if anonymous is right or not, but it certainly sounds more painful.

Time to do an experiment. HPLC-grade DCM vs. varnish-stripper-grade DCM.

I need someone's arm.

kaicevy said...

I've always wondered and now I am asking the world: Why does methylene chloride hurt when I get it on my skin? It's especially bad under a ring

Anonymous said...

I would not purchase DCM from Belgium. I heard it is more painful that the one made in U.S.A. :-)

Chemgeek said...

What's Belgium?

milkshake said...

Especially not the belgian stripper grade - I traveled to Lutich once...

Anonymous said...

If you've gotten enough on your skin to burn, you've definitely gotten enough into your system to be trashing your liver.

The skin burn would be the least of my worries...ever heard of angiocarcinoma?

And ethanolamine to treat a burn? My gawd you organic chemists are nuts. How about NaHCO3, it's only a heck of lot safer and cheaper...

Anonymous said...

i like Belgian strippers!