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Topic: Protecting hands from MeOH & DCM?  (Read 31345 times)

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Offline Brilla

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Protecting hands from MeOH & DCM?
« on: December 04, 2009, 09:21:18 AM »
Sorry if this is a very simple question for postgrad / professional forum, but I have some confusion regarding a possible safety issue. I'm wondering if organic chemists normally wear protective gloves when working with solvents such as dichloromethane and methanol? In my experience, very few people do so, but I have no idea if that's the norm or the exception.

I'm trying to figure out the safest way to conduct my research, without introducing a lot of contamination into my samples. Most people I've asked say that wearing gloves may introduce contamination, and thus they opt not to wear them. Or else they just don't bother to wear gloves, because it's a hassle. The MSDS says to wear gloves, but I'm starting to realize that in the real world things are not always done according to the MSDS.

I'm not talking about spilling huge amounts of DCM or methanol on my hands, just a few drops every now and then (can't seem to avoid it). But I suppose the harmful effects do add up. Is it something folks are generally concerned about? Or am I better off just ignoring the occasional drop or three and concentrating on keeping my work clean? I know no-one can make my decisions for me, but it would help if I could get an idea of whether or not this is even considered a safety issue.

Thanks for any input!

Offline reflux

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Re: Protecting hands from MeOH & DCM?
« Reply #1 on: December 04, 2009, 09:32:25 AM »
I always wear nitrile gloves when I work in the chemistry lab.  They protect well against a few drops of methanol.  But even a few drops of dichloromethane will go through the gloves.  The vapors get trapped in there and start to burn your hands.  Still I think wearing them helps... just remove your gloves immediately after you spill something on them.

Offline Brilla

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Re: Protecting hands from MeOH & DCM?
« Reply #2 on: December 04, 2009, 09:41:47 AM »
Thanks for your reply!

"But even a few drops of dichloromethane will go through the gloves.  The vapors get trapped in there and start to burn your hands."

Do you actually feel a burning sensation? Whenever I get DCM on my gloves, I sort of feel it going through the gloves, but I don't feel burning or anything like that. Same as when I spill DCM and MeOH on my bare hands, I just feel the coolness as the solvent evaporates and nothing more. Maybe that's why a few drops every now and then easy to ignore, and seems to me like many do ignore it. If I may be curious, do others in your lab wear gloves to protect against organic solvents?

Offline stewie griffin

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Re: Protecting hands from MeOH & DCM?
« Reply #3 on: December 04, 2009, 09:52:54 AM »
I work in a total synthesis lab. We all wear nitrile gloves anytime we are doing chemistry. We use them when using solvents, when weighing out reagents, when running columns, whatever. I don't see any good reason to not wear them.

Offline stewie griffin

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Re: Protecting hands from MeOH & DCM?
« Reply #4 on: December 04, 2009, 09:53:30 AM »
Oh, and yes I feel my hands tingle/burn when I get DCM on them too.

Offline Brilla

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Re: Protecting hands from MeOH & DCM?
« Reply #5 on: December 04, 2009, 10:03:11 AM »
"I don't see any good reason to not wear them."

When I've asked why people don't wear gloves, I've been given several reasons. Such as:

-"Gloves are a possible source of contamination."
-"Gloves make you careless with chemicals; it's better not to wear them and stay alert."
-"You'd need to take the gloves off and on all the time and it's just too much trouble."
-"We're not really dealing with anything that dangerous." (Referring to DCM, MeOH etc.)

I'm starting to think these may not be good reasons, however. Except maybe the contamination one, if it's true, and if the occasional exposure is not too severe a health risk. I wouldn't want to risk my health for the sake of good science, though!

Sorry to bother you guys with something that seems to be trivial to many...  It is probably apparent I'm rather new to lab work.

Offline tmartin

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Re: Protecting hands from MeOH & DCM?
« Reply #6 on: December 04, 2009, 10:26:30 AM »
I have to agree 100% with stewie griffin.  I wear gloves just about any time I plan to work with a chemical or touch a flask or chemical bottle.  In response to some of the concerns, I have never had a problem with gloves contaminating my product, nor do I know anyone who has in the entire department.  I don't think wearing gloves will make you careless with chemicals, quite the opposite, I think.  Wearing gloves means you're taking some of the proper safety precautions.  There are days when I wear the same pair of gloves for 4-5 hours, and sometimes only 4-5 minutes.  But really, are you that busy that you can't take 10 seconds to put on or take off gloves?  Sure, a drop of methanol or a drop of methylene chloride may not seem like much, but do you really want to get into that mindset of "its only a little bit of some chemical, I can take it"...

Risking your health needlessly in lab is kind of silly (as you note), so I'd suggest just put on a pair of gloves.  As you're new to lab, now if probably the best time to start good habits.  :)

Offline stewie griffin

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Re: Protecting hands from MeOH & DCM?
« Reply #7 on: December 04, 2009, 10:33:33 AM »
Don't feel embarrassed at all. Safety is much more important than most people make it out to be. You should know full well the potential hazards from exposure to various chemicals. DCM is a carcinogen, so I'd really like to not get any drops on my hands, though at times I do get a few drops on my gloves. I have never put on gloves and then had my attitude change to a "careless" one. In fact, when I don my gloves and safety glasses, I'm reminded of the hazards of working in a chem lab. When I work with nasty chemicals I put on my safety coat, and then I really become aware of what I'm doing and feel more focused on the task at hand.
It can become annoying to take the gloves on and off... but is it really that hard to do??
Lastly, it's interesting that people have said the gloves can be a source of contamination. One reason I wear gloves is that I don't want the oils from my hands getting on my materials or glassware. For example, if I tare a vial, then put my product in there and vac it down to get my % yield, I don't want the oils from my hands affecting the result (and when you are working on a few milligrams scale, this becomes important). So I wear gloves so as to not contaminate my materials.
In the end... do yourself a favor and wear gloves  ;D
BTW, I think "We're not really dealing with anything that dangerous" may be the famous last words of some chemists  ;)

Offline Brilla

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Re: Protecting hands from MeOH & DCM?
« Reply #8 on: December 04, 2009, 10:38:40 AM »
tmartin:

"But really, are you that busy that you can't take 10 seconds to put on or take off gloves?"

No, I'm not that busy. It's just that I'm sort of frowned upon when I do wear gloves in the lab, mainly because of the (possible) contamination issue. It doesn't matter as such, I'm an adult and I will do as I deem best. It's just that I haven't really had any outsider perspective on this issue before. And when I see almost no-one wearing gloves in the daily lab work, it just starts to seem like a non-issue, something I should not even be concerned about. But I am concerned about my health, and don't want to risk it.

"Sure, a drop of methanol or a drop of methylene chloride may not seem like much, but do you really want to get into that mindset of "its only a little bit of some chemical, I can take it"..."

I guess it depends on the chemical. I wish I had more chemical safety knowledge, so that I could make informed choices as to which chemicals and in amounts constitute a health risk. At the moment I don't really have that knowledge. But I don't have the "bring it on, I can take it" sort of attitude at all, I can assure you. I'm trying to protect myself as well as I can. And if contamination from lab gloves is not a real problem, then I see no reason not to wear gloves all the time. It doesn't matter if I'm the only one doing so.

"Risking your health needlessly in lab is kind of silly (as you note), so I'd suggest just put on a pair of gloves."

I think I will do that! Thanks for your advice!

Um. should I worry about the fact that I have been getting DCM and MeOH on my hands for some months now...? I guess it's too late to do anything about that anyway...

Offline Brilla

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Re: Protecting hands from MeOH & DCM?
« Reply #9 on: December 04, 2009, 10:46:23 AM »
stewie griffin:

"You should know full well the potential hazards from exposure to various chemicals. DCM is a carcinogen, so I'd really like to not get any drops on my hands, though at times I do get a few drops on my gloves."

Well, that's the thing - I don't really know the potential hazards of the chemicals I'm working with. I wish I'd had more safety training. I know MSDS for DCM says: "Possibly carcinogenic in humans. Possible mutagen." I don't really know how serious a threat that constitutes. I don't want to quibble here, because I fully agree with everyone here that unnecessary risks are stupid in any case! What I mean is, when I've discussed this issue with a colleague, they've just shrugged and said: "Well, it may or may not be a carsinogen, who knows. Don't drink it." So, it's often not obvious to me which information I should base my lab routine on.

Thanks again for the input and good advice!

Offline Brilla

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Re: Protecting hands from MeOH & DCM?
« Reply #10 on: December 04, 2009, 10:52:02 AM »
"For example, if I tare a vial, then put my product in there and vac it down to get my % yield, I don't want the oils from my hands affecting the result (and when you are working on a few milligrams scale, this becomes important). So I wear gloves so as to not contaminate my materials."

Oh, I forgot to comment this. Whenever I do this, I handle the vial with pincers, so as not to get oils from my hand onto the vial. It can really affect the result, I agree.

Offline stewie griffin

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Re: Protecting hands from MeOH & DCM?
« Reply #11 on: December 04, 2009, 10:58:00 AM »
Well it can be tough to be safety conscious when those around you are cavalier about it. Just stick to guns and do what you know is right.  Use the MSDS as you said, and when you want more info ask your professor, ask other labs in the department, or come on here and ask  :) We'll help.
BTW, what kind of research lab are you in (if I may ask). In my experience, the analytical/physical students are usually super crazy about safety b/c they don't usually know if an organic chemical is toxic or not so they play is safe with everything. And the organic/inorganic folks are more aware of what's dangerous and take precautions when needed, though gloves/eyewear is a minimum.

Offline Brilla

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Re: Protecting hands from MeOH & DCM?
« Reply #12 on: December 04, 2009, 11:29:34 AM »
"Just stick to guns and do what you know is right."

I will, but I need to find out what is right first. :-) Wearing gloves seems to be the smart thing, so I will do that. I'm sure I'll come across other questions at some point. It's good to know I can get help somewhere!

"...when you want more info ask your professor, ask other labs in the department..."

Well, this part is tricky. If the safety culture in the lab is not brilliant, then it can probably be assumed the professors are not super keen on safety themselves. In the lab where I am now, the professor seems actively averse to wearing gloves. And going to another lab in the department and asking them can feel somehow sneaky. It's kind of sending the message: "We're doing things wrong in our lab, don't you guys think so too?" I fear doing that may brand one as disloyal. That's why it's brilliant to have a forum like this!

"In my experience, the analytical/physical students are usually super crazy about safety b/c they don't usually know if an organic chemical is toxic or not so they play is safe with everything. And the organic/inorganic folks are more aware of what's dangerous and take precautions when needed, though gloves/eyewear is a minimum."

I'm doing organic chemistry. I've worked in two labs, and I wouldn't say eyewear and gloves are widely used in both of them.

In one lab, one person wore gloves occasionally. Everyone who didn't have glasses wore eye protection. Those people, who had glasses anyway, usually didn't wear extra eye protection. Everyone wore a lab coat.

In the other lab, no-one wears either eye protection or gloves. Some people wear a lab coat. I'm not sure if people are always aware of the health risks of the chemicals they're handling (and I'm very unsure of those myself, so I can't really pass judgment).

Offline tmartin

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Re: Protecting hands from MeOH & DCM?
« Reply #13 on: December 04, 2009, 02:45:54 PM »
I must admit that I am quite surprised that there seems to be a "culture" of not wearing gloves in your lab (I don't mean to sound judgmental, I've just never encountered anyone with that mentality).  I've heard from some people I know that "in the old days" they would not wear gloves or goggles/glasses, pipet by mouth, those sorts of things, but mostly now the consensus I see is wearing the typical personal protective equipment.  I find it interesting people would wear lab coats but not gloves, just my point of view, but if I don't want a chemical on my clothing, I probably don't want it on my hands  :P.

One way to look at it, if you are wearing gloves and running a reaction... when you purify it, get a nice clean NMR/IR/MS/etc. and you can use that as evidence that "hey, my gloves didn't mess up my reaction, and I felt safer wearing them".  On the flip side, if somehow your gloves contaminate your product, I am extremely sorry for telling you it is highly unlikely  :-\  (I would still bet that its a very slim chance of happening).  At any rate, like stewie said, just do what you think you need to do to be safe, if the MSDS says wear gloves and a lab coat, and you feel that's how best to be safe, then do it, and hopefully people will recognize you're following proper safety procedures and not give you a hard time.

Offline orgopete

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Re: Protecting hands from MeOH & DCM?
« Reply #14 on: December 05, 2009, 12:34:06 AM »
I want to comment on two topics here.

I generally didn't wear gloves unless I knew I was working with something I did not want to have contact with. I usually wore the heavy neoprene gloves.
There are days when I wear the same pair of gloves for 4-5 hours, and sometimes only 4-5 minutes.

I never liked working with anyone who wore gloves. The quote explains why. If the people wearing gloves discarded them every 5 minutes I might feel differently. I really don't like touching chemicals. I really really really don't like touching your chemicals. Take those gloves off and throw them away when you complete your transfers please. That little bit that you don't mind getting on your gloves, I do.

I like the feedback of knowing that I may have inadvertently contacted something. I wash my hands. We are not talking about the conc sulfuric here, I have my gloves on for that one.

It is a pet peeve of mine to see student touch their chemicals with their gloved fingers. I make them throw the gloves away and tell them to not touch anything. You know when they touch something, they are just going to spread it around. I am a forceps and spatula (and funnel) person. Let's keep those chemical away.

Re: MSDS
I am okay with some form of warning labels, but if I were a manufacturer and wanted to avoid a law suit, I would take extreme measures to warn you about the hazards of the chemical, even if it were an item commonly found in foods. Any of you chemophobes had any alcohol or mind altering drugs?

My preferred source for toxicity is the Merck Index. I like to learn about risks from actual studies. I want to know if I am in the possession of a chemical that can kill everyone in the lab or something that at worst has an unpleasant smell (that is any smell at all). I don't feel I know that kind of crucial information from reading the MSDS.

Lest everyone think I am a careless slob working in a chemistry lab, I have since retired from it. I worked in a synthesis lab for over 25 years. I kept everything in the hood. I know how to weigh out really noxious samples without your even being able to detect my having do so. I love those Luer-lock syringes.

So, check the toxicity data for dichloromethane. While you are at it, check chloroform as well. Also, while you are checking, how much are you breathing in (what I worried the most about) or do you have a gas mask on as well? (It is so ironic to see my chemophobic colleagues outside on a cigarette break.)
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