Mabus
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Dichloromethane EU restriction proposal (text)
Came across the DCM banning proposal by Carl Schlyter, the one which restricted its use, and decided to share it, unless you've already seen it. Found
it some time ago, but only now I had enough time to properly analyze it.
The full text can be found here:
http://www.europarl.europa.eu/sides/getDoc.do?pubRef=-//EP//...
I am going to take a look at some of Schlyter's arguments:
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In its industrial application, however, it is entirely possible to protect workers and the environment when using this chemical. It is predominantly
when it is sold to consumers that there are problems. |
Yes, because the average consumer is too dumb to work with volatile stuff, it's not like industrial units ever have accidents And clearly consumers
use DCM products as often as an industrial facility. *rolleyes*
| Quote: | | DCM is a noxious chemical in that it is carcinogenic, has a narcotic effect and has harmful effects on health. It is easy to be affected by it.
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So... that's pretty much every solvent save for water.
| Quote: | | By the time you smell DCM, you have already exceeded the safety limit by a factor of three, which makes it extremely difficult to protect yourself
against. |
How much DCM? Air concentration? Duration of exposure?
| Quote: | | A proper protective set-up consists of very high-spec gloves that have to be changed every three hours. You have to have equipment that usually costs
around EUR 2 700 with an independent ventilation system. |
WHAT? For a facility that's pennies. I don't see what that's a problem. And most corrosion resistant air pumps are much cheaper than 2,700 € (unless
you need a bigger pump), and that's from authorized sellers.
Also if the label says to use the DCM products ONLY in well ventilated areas or outside, then... don't use it in confined areas? I mean, you have the
same issue if you're using other solvents, like say, you're painting inside, your entire house will be filled with solvent vapors. And if they're
flammable, there will be an explosive hazard. At least DCM is not flammable.
| Quote: |
The fact that this chemical is used today is very much dependent on the fact that it is used illegally. |
Maybe I have reading comprehension issues, but what is this quote supposed to mean?
| Quote: |
This meant that it was also important to restrict and prohibit use by professional users. It is often the self-employed and companies consisting of
just a few staff who are out there cleaning up graffiti or stripping paint. The protective equipment is very often left at home or just not available
at all. Banning this chemical is therefore, to a very large extent, a worker-protection issue. |
So... because some people are not using protection equipment "very often" (citation needed), that's an argument to ban it? Should we also ban fire
because very often chefs don't wear fire or hot oil protection?
| Quote: |
I think it will suffice to quote the German Chemical Industry Association’s own text, which states that even if there is good ventilation, paints
are stripped in restricted areas, the paint residues removed are collected and the DCM pots closed immediately, the exposure limit is still exceeded
on a regular basis. That is why self-contained breathing equipment is needed. |
Well... duh!
| Quote: |
In respect of DCM, there are those who argue that the alternatives may possibly be at least as dangerous, if not more so, but the assessments by the
Commission and others have clearly shown that the alternatives are significantly less dangerous. |
[Citation needed]
I am not going to touch the arguments brought by the other participants, because that would take too long and this wall of text is enough. Most of the
arguments of the other members can be pretty much be summed up as "DCM is bad mkay, must ban". Oh and one person (Zuzana Roithová) had to mention
terrorism. *sigh*
But to me, the silliest argument was brought by Gyula Hegyi:
| Quote: | | According to the compromise text that has now been adopted, dichloromethane can in future be used as a paint stripper only in industry and under
strict safety regulations. Consumers and professionals will have to strip unwanted paint using one of the many equally effective but non-harmful
alternative chemicals or, for instance, by pyrolitic/thermal stripping. |
Yes, burning paint is safer than using DCM... let that sink in for a moment.
The only person that showed some common sense was John Bowis who asked Schlyter how safer are the alternatives, when most of them have been found to
be actually harmful.
I can't say I'm surprised by the general attitude of the EU members, but it's kind of worrying to see that big decisions are made with half-arsed
arguments.
[Edited on 26-3-2016 by Mabus]
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macckone
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Otc dcm in pure form has pretty much been unavailable for more than a decade in the us. This is due to voc restrictions. I am not 100% certain but I
believe cali bans it completely in some areas if not the whole state. Chloroform is less volatile but easy to make and can often be used as a
substitute. Ethyl ether is also easy to make if somewhat dangerous. It should be possible to do an otc synth of dcm but it may require exotic
equipment.
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Mabus
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Quote: Originally posted by macckone  | | Otc dcm in pure form has pretty much been unavailable for more than a decade in the us. This is due to voc restrictions. I am not 100% certain but I
believe cali bans it completely in some areas if not the whole state. Chloroform is less volatile but easy to make and can often be used as a
substitute. Ethyl ether is also easy to make if somewhat dangerous. It should be possible to do an otc synth of dcm but it may require exotic
equipment. |
Sadly the only somewhat accessible ways to make DCM involve the reduction of a halomethane like chloroform (which you can make it via haloform
reaction) with zinc and glacial acetic acid/hydrogen chloride in ethanol or tetrachloromethane with sodium hydroxide and iron(II) sulfate or
isopropanol with acetonitrile. The only unknown is the yield.
And even if the yield is great, you will still need to perform a fractional distillation. Guess there's no easy way to obtain larger amounts of DCM.
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chemrox
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None of the synthetic routes make sense to those who want to use it as a solvent. Too expensive and not convenient. Banning DCM is just one more step
in the inevitable ban on synthetic chemistry by anyone other than petrochem and big pharma. Work while you can my friends.
"When you let the dumbasses vote you end up with populism followed by autocracy and getting back is a bitch." Plato (sort of)
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aga
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Well, once could always look up how DCM can be made, and then refine that process i guess.
Think i have some nickel somewhere ...
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macckone
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Dcm is made by combining methane with chlorine. A quartz tube with feeds at one end and outlet at the other should do it. Dilution with nitrogen or
carbon dioxide would help avoid an overly exciting reaction and keep yields of the correctly chlorinated chemical higher.
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Mabus
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| Quote: Originally posted by macckone | | Dcm is made by combining methane with chlorine. A quartz tube with feeds at one end and outlet at the other should do it. Dilution with nitrogen or
carbon dioxide would help avoid an overly exciting reaction and keep yields of the correctly chlorinated chemical higher. |
Correct me if I'm wrong, but doesn't that reaction tend to produce all the chloromethanes, regardless of the mole ratio of methane and chlorine?
And isn't chloroform the major product of the said process?
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Texium
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| Quote: Originally posted by Mabus | | Quote: Originally posted by macckone | | Dcm is made by combining methane with chlorine. A quartz tube with feeds at one end and outlet at the other should do it. Dilution with nitrogen or
carbon dioxide would help avoid an overly exciting reaction and keep yields of the correctly chlorinated chemical higher. |
Correct me if I'm wrong, but doesn't that reaction tend to produce all the chloromethanes, regardless of the mole ratio of methane and chlorine?
And isn't chloroform the major product of the said process? |
Yes, it does. You were correct in your earlier
assertion that there isn't a feasible way for the amateur to synthesize useful quantities of DCM.
However, apparently in some parts of the US, Jasco brand paint stripper is available. It is mainly DCM (60% minimum), with the balance being methanol,
petroleum ether, and some sort of polymer. See the MSDS here. I have been looking for it in Texas, but have been unable to find it so far.
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unionised
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All the points made against letting the public buy DCM are valid.
Lte's (just for balance) have a look at the OP's counterpoints
"Yes, because the average consumer is too dumb to work with volatile stuff, it's not like industrial units ever have accidents And clearly consumers
use DCM products as often as an industrial facility. *rolleyes*"
Well, enough people get harmed by it to suggest that "the man in the street" is too dumb to use it.
Even in industrial setting where it can be well controlled there are still problems.
It makes sense to use something else- for example, benzyl alcohol or NMP
"So... that's pretty much every solvent save for water."
Not really, no.
Not all solvents are carcinogenic. And many of themare a whole lot less volatile so they don't produce such clouds of toxic fumes.
"How much DCM? Air concentration? Duration of exposure?"
Enough that you can smell it i.e about 250 ppm (from this)
https://www3.epa.gov/airtoxics/hlthef/methylen.html
and the usual timescale for exposure measurement is 15 minutes.
WHAT? For a facility that's pennies. I don't see what that's a problem. And most corrosion resistant air pumps are much cheaper than 2,700 € (unless
you need a bigger pump), and that's from authorized sellers.
Also if the label says to use the DCM products ONLY in well ventilated areas or outside, then... don't use it in confined areas? I mean, you have the
same issue if you're using other solvents, like say, you're painting inside, your entire house will be filled with solvent vapours. And if they're
flammable, there will be an explosive hazard. At least DCM is not flammable.
OK, so, for a start can you let me know where I can get a good fume cupboard system for 2700 euros?
Can you explain how I take my kitchen cupboards window sills and skirting boards outside to strip the paint from them please?
And, since the discussion is about stopping consumers (rather than industry) using the stuff the fact that 2700 is "pennies" to a commercial
organisation has no relevance.
And, this may not have occurred to you, but the alternative solvents used for this are not very volatile and they aren't flammable either. Why did you
raise that?
"Maybe I have reading comprehension issues, but what is this quote supposed to mean?"
It means what it says. Most people still using it are breaking the (current) law.
"So... because some people are not using protection equipment "very often" (citation needed), that's an argument to ban it? Should we also ban fire
because very often chefs don't wear fire or hot oil protection?"
No, it's a reason to restrict it.
Yes, we should restrict fire, just as soon as we can find an alternative that works as well as fire. In the same way we should restrict the use of DCM
because there are safer alternatives.
And so on.
It seems there are half arsed arguments on both sides.
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Magpie
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Have you checked Home Depot?
The single most important condition for a successful synthesis is good mixing - Nicodem
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