Sciencemadness Discussion Board

DCM/CHCl3/CCl4 waste

Jor - 5-11-2008 at 14:52

I own both these 3 chemicals, but before I experiment with them I want to be sure I can properly dispose of it. This will be done as 'paint stripper' waste. Now what bottle is best to put it in? Will aluminium work? I heard CCl4 reacts with reactive metals so Im not sure? How does it react with metals?

And HDPE? Will it diffuse through the plastic?
I wil not use glass. So either aluminium or HDPE. What's the best option?

smuv - 5-11-2008 at 15:09

Neither material is acceptable.

Solvent grade DCM is provided in plated ferrous tins; I am not sure of the plating material but I know it can be easily soft soldered.

Your best bet is to recycle your solvents. Sometimes when I work on smaller scales I just let the DCM evaporate, but I don't think this would be good for larger quantities of solvent. Other than that, proper disposal at a hazmat facility is your other viable option. In the US, once a year most communities have a cleanup day when you can bring in your hazmat goods for free disposal, maybe similar programs exist in your community. You could look into basic hydrolysis of your chloromethanes, but I doubt this is an efficient option.

P.S. The word both can only refer to 2 things not 3.

So you could say:
Both DCM and Carbon Tet. are wonderful solvents.

But you can't say:
Both DCM, Carbon Tet. and chloroform are wonderful solvents.

[Edited on 11-5-2008 by smuv]

[Edited on 11-5-2008 by smuv]

not_important - 5-11-2008 at 18:45

Very few plastics are resistant to halocarbons, most quickly being reduced to soft glop at the best.

Well sealed metal containers, such as the solvents are sometimes sold in, or glass are the best bets. Ferrous canisters, stainless steel if you can get it, seem to be your only option given your rejection of glass.

You come out ahead reclaiming halogenated solvents, as they are becoming increasingly regulated, expensive, and difficult to obtain. Try to avoid mixing solvents that form azeotropes, storing each type as "solvent XYZ for reclamation" until you can actually get around to reclaiming it; the labeling sometimes avoids the hazmat tag as you don't call it "waste".

If you store used solvents in metal containers make sure there are no free acids in the solvent mixtures.

kclo4 - 5-11-2008 at 19:15

What is wrong with glass?

Jor - 6-11-2008 at 14:21

I may let small amounts of DCM evaporate. I will not let chloroform or tetra evaporate.

I never recycle solvents. It's just not worth the hassle. I dont use them often and only small amounts. And DCM is cheap, 10 EURO a Liter. Chloroform 15 EUR a liter. CCl4 is about 40 EUR a liter (or even more), so that might be recycled.

The reason I do not want to use glass, is because I'm scared of overpresure in the bottle (some traces of chemicals might react is a waste bottle, and might rupture the bottle. Metals can withstand a large overpressure, HDPE also (and is not dangerous when it explodes), but glass cannot, unless I buy expensive Duran bottles.

Glass might be possible, but I need a cap wich is used on H2O2 bottles as well, wich can let overpressure escape.

Another possibility would be leaving the cap off the bottle, but all solvent will have evaporated in notime then.

Im also thinking of a a way to dispose of benzene. Small amounts I will just burn. Larger amounts, maybe I just open a lottle of hardware store toluene/ligroin/xylene, pour some out, add the benzene, and dispose of it as household waste. We'll see. :P

Klute - 6-11-2008 at 14:54

You do not have to be afraid of over pressure in glass bottle with DCM.... The pressure will never exceed enough to cause more than a slight pffchit when opened: I have used several 2.5L bottles of DCM in summer where the temp can exceed 40°C easily, and there never was any frighteningly high pressures. Really not a problem.

Metal cans might cause some problems with chloroalkanes, i'm not sure up to which extent though, but I'm definate I've never seen any low chloroalkane in aluminium bottles for example.

I would say go with the glass, nothing to be afraid off.