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What is the truth about Methyl Ethyl Ketone??

cjensen

Well Known Member
I've heard it both ways..."DON'T EVER GET THAT STUFF ON YOUR SKIN!!!!" and "Ah, MEK won't hurt you." Both of those are nearly exact quotes from two different A&P IA's. Both are of similar age, both work (or worked in one case-retired early) on everything from homebuilts to Gulfstreams. I can't find anything on the can that says anything other than "avoid contact with skin." But if it does, "wash it off". "If irritaion persists, consult physician." Nothing about "this stuff will kill you if you get it on your skin." Avoiding eye contact is obvious, but what is the real harm of getting it on your skin, if any? Does it cause cancer in lab rats or something? Does your skin eventually fall off from too much exposure?

:confused: It's just a thinning compound and cleaning agent...
 
Chad,

The truth is, it isn't a vitamin or essential mineral. It doesn't have calories and cannot benefit you in any way. Therefore, your body doesn't need it.

On the other hand, you will become "exposed" throughout the building process. The best way for it to find it's way into your system is by drinking it, sniffing it or MOSTLY absorbing it under your fingernails. That is how we usually get it into our bodies. Wear gloves while handling it and it will keep it from going under your nails.

Once inside the body, it attacks the liver. That is why I usually mix mine with Captain Morgan's!

Remeber, latex is your friend once again!

:D CJ
 
cjensen said:
I've heard it both ways..."DON'T EVER GET THAT STUFF ON YOUR SKIN!!!!" and "Ah, MEK won't hurt you." Both of those are nearly exact quotes from two different A&P IA's. Both are of similar age, both work (or worked in one case-retired early) on everything from homebuilts to Gulfstreams. I can't find anything on the can that says anything other than "avoid contact with skin." But if it does, "wash it off". "If irritaion persists, consult physician." Nothing about "this stuff will kill you if you get it on your skin." Avoiding eye contact is obvious, but what is the real harm of getting it on your skin, if any? Does it cause cancer in lab rats or something? Does your skin eventually fall off from too much exposure?

:confused: It's just a thinning compound and cleaning agent...

I found that if I got it on my fingers, a thick layer of skin would peel off over the next couple of weeks. I always wear good quality latex (not vinyl nitrile!) gloves when using MEK. Two layers of gloves are better.

It takes a few months after damaging your skin for everything to heal up.

Vern Little
 
MEK is definitely a physical hazard, but it is less hazardous then some of the other chemicals used in paint related chemicals.

The problem is that MEK is often used as an ingredient with other chemicals and you never know what you're splashing on your skin. One side note is that Benzene, a very common ingredient in many paint related chemicals, has been directly linked to some types of Leukemia.

I worked directly with just about all the paints and chemicals for a 25+ year period in my auto restoration business before I changed to a different unrelated business so I hope my advice counts for something when I say that it's a waste of time to read labels (or ask other's "opinions") to see if a material is safe to handle with your bare hands.
Save your time and long term health by simply keeping a box of examination gloves near your bench and use 'em all the time.
 
Read the MSDS

Highflight said:
The problem is that MEK is often used as an ingredient with other chemicals and you never know what you're splashing on your skin..

This is the exact reason you should read the MSDS for the product you are using...
The manufacturer has to acknowledge all of the ingredients in his "chemical soup", and give you the hazards for his particular mix...

They are usually available on line...
Here is a typical one from DuPont for one of their Imron products...
http://www.performancecoatings.dupont.com/dpc/en/us/html/prodinfo/daf/US_en_GNRC_21-0_RFN.pdf

gil in Tucson
 
The bigger question is why use it so often. I've built 7 airplanes, rebuilt and repaired many more and I can count the times I've used MEK on 10 fingers. Lacquer thinner or acetone is safer and will do ALMOST anything that MEK will do. Unless you are working with polyurethane paints, most of the time lacquer thinner will do nicely.
 
I'm in the finishing straight for my 4 and I've never owned an ounce of MEK. You can get by just fine with other safer products.
 
Highflight said:
Save your time and long term health by simply keeping a box of examination gloves near your bench and use 'em all the time.
Having built a tube and fabric airplane and using a lot of MEK I can attest to the fact that this chemical is something to be careful around. I have used latex gloves with the stuff and I have used it with no protection, either on my hands or breathing. I can say that the fumes can and will give you one whale of a headache if you mess with it for any length of time in an enclosed environment. I have had it exposed on my hands for long periods of time with little or no effects to notice but I don't have to breathe it very long before I notice the headaches coming on. I can imagine what those chemicals are actually doing to my body if my brain is trying to tell me to stop it by giving me those serious headache pains.

Take the necessary steps to protect yourself in whatever way will work best for you but don't sluff these potent chemicals off as nothing to worry about. It may not bite you now but it will eventually. Maybe it would take 25 or 30 years to affect you. But do you think that is worth it? I mean, after all, I want to live longer than 25 or 30 more years from now. I want to live forever for that matter. 25 or 30 years doesn't seem very long at all when you really think about it. Why increase the odds if you don't have to?
 
Use the nitrile or PVC coated gloves and plenty of ventilation. Even though it's not as bad as benzene, vinyl chloride, trichlor, etc., I believe exposure to these things definitely increases health problems/cancer risk.

Just an opinion, but based on 18 yrs experience in the petrochem manufacturing business.
 
Referencing the original post, the folks who say MEK won't hurt you are wrong. The folks who say it'll kill you are right, but not the degree they think.

Most of the discusison around MEK doesn't really revolve around either, it revolves around quotes like "I'm using (name of chemical here) because MEK is so hazardous."

That's wrong, according to the latest research. MEK does not appear to be any worse than the alternative chemicals one usually sees listed. On my reading on the EPA site, which just removed MEK from some hazardous checmical-like status, although I don't trust anyone in Washington to do anything for reasons other than someone paid them to.

MEK appears to be an effective solvent, although I only used it for cleaning up ProSeal. I don't use it for cleaning aluminum prior to painting. Give me a Scotchbrite pad and a bottle of Dawn for that and I'll be fine.

Use your head, don't let any chemicals touch your skin and keep a respirator handy whenever using any chemicals, as well as when using a deburring wheel (you ever notice all that grey **** on your workbench when you deburr with the Scotchbrite wheel? That CAN'T be good if it goes up your nostrils!)
 
Great discussion on MEK. I've always viewed it as a chemical to protect myself from, and will continue to do so. I was just thrown for a loop the other day when this guy told me 'not to worry about it, it won't hurt you'! The MSDS is enough to make me want to never use it again, but it does work great for cleaning up sealant. I think I'll switch to acetone after the tanks are finished up. :rolleyes:
 
cjensen said:
I've heard it both ways..."DON'T EVER GET THAT STUFF ON YOUR SKIN!!!!" and "Ah, MEK won't hurt you."

Depends on where you live. Down here in the south you can have it straight up or over rocks after 5 PM ;) . I think it causes cancer in California though, lots of things cause cancer in California. Glad I don't live there anymore. :D
 
From my past environmental/safety/IH days:

No hydrocarbon is great for our existance, but as far as strong solvents come, MEK and acetone are relatively non-toxic. FWIW, laquer thinner is not safer than MEK- it likely contains benzene in its formulation, and benzene (and its close relatives) is a very toxic carcinogen. The other bad actors generally contain chlorine, and chlorinated solvents have shown toxicity with the liver and can harm our upper ozone layers (carbon tetrachloride, tetrachloroethelene (TCE), and maybe methylene chloride. 111-trichloroethane (TCA) and the freon family are safe (unless burned).

Keep in mind, solvent danger comes in many forms: toxicity, oxygen displacement, flammability, and some develope allergic reactions in some individuals. All solvents are irritating to some extent; they disolve and remove the natural oils in your skin.
 
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I like the Coleman fuel that Van recommends!

It isn't as potent as MEK, either on the material or the nose! Besides, it is only $5 a gallon and I am CHEAP!

;) CJ
 
Dangerous Solvents

I can't even buy MEK where I live, so I use Acetone. Chemically, they seem to be very similar.

One thing to keep in mind is that you need to also worry about the stuff you are using the solvent on - it will also get into your skin, since you've just dissolved it.

I never get any solvent on my skin or breath it. They may be as safe as spring water, but I'm not taking any chances. I need to be around to teach my grandkids to fly.
 
MEK neurological problems

I'll also admit something else... I've read MSDS for MEK before, but this is the first one that said "May produce numbness in the extremities. "

Well, that explains a lot. A couple of years ago, I had numbness in my arms/hands, and feet. I was checked for a bunch of things. It got so bad I could not hold a cup of coffee.

These symptoms have mostly dissappeared... and I haven't used MEK much in the last year.

Was MEK the root cause? Who knows... but I'm going to dig deeper to find out. It may also have been acetone, which I've heard is actually worse than MEK.

Vern Little
 
MEK tox summary

Here's a succint tox summary for MEK from the State of New Jersey. What it (generally) says is that MEK is a reproductive and neurological toxicant in repeated exposures of high enough concentration. The summary has some excellent respirator selection advice.

http://www.state.nj.us/health/eoh/rtkweb/1258.pdf


I'm just starting my 7A tail section, and I'll be experimenting with a safer solvent - - ethanol (aka vodka) - - where possible.
 
I've tried numerous different types and brands of gloves to protect myself from MEK, but haven't found any that will hold up to it for very long. All the gloves I've tried swell and disintegrate after several minutes. Anyone have any specific recommendations (brand and type) of golves that will keep MEK and/or laquer thinner from getting to your skin? The folks at the local safety supply company told me that latex gloves don't dissolve as rapidly as the others, but that MEK "goes right through" and is absorbed almost as rapidly as if wearing no gloves at all?????
 
Darn you Chad

Chad,
I read all this late last night and then went to bed. Dreamed (nightmare) about MEK and Muratic Acid seeping into my body!!! (I had just clean my hanger floor with acid two weeks ago) Woke up and thought I was dying :eek:
 
MEK

Hmmm.... The Army wont let me use it anymore... I've heard it attacks your liver... It's some bad arse stuff for sure! If you take reasonable precautions like the blue gloves... not the white ones... and wash your hands on a regular basis you should be fine. Please dont breath it. I would reccomend outside use only if possible. Please have an eyewash station near as well. There is some skin barrier lotion I've seen that would also be a good thing to use when working with dangerous chemicals.
Best regards
Brian Wallis
N41RC
N357BW reserved.
 
What's it for?

Other than thinning polyurethane paint and causing possible health risk problems, what is MEK good for?

Driving down a busy road with the windows down probably causes you to breath in enough toxic fumes to kill a horse. (good thing we're not horses)! :D
 
JACKR said:
Chad,
I read all this late last night and then went to bed. Dreamed (nightmare) about MEK and Muratic Acid seeping into my body!!! (I had just clean my hanger floor with acid two weeks ago) Woke up and thought I was dying :eek:
HA!! That is hilarious!!!
 
cjensen said:
The MSDS is enough to make me want to never use it again
Read the MSDS for other common chemicals, too. You'll find yourself thinking that about a LOT of stuff...
 
MEK?

After 35 years in the chemical and hazardous waste industries, I feel marginally qualified to speak to the issues!

All chemicals or their residual derivatives (including Ethyl alcohol) are processed by the liver. That's why alcoholics experience liver failure. Less exposure is better. For some people, any exposure is toxic.

Numbness in the extremities is a clear sign of hypoxia, a common side effect of exposure to solvents. Less exposure is better.

Don't fool yourself. Most general grade lacquer thinner is 10 - 25% MEK. Depends on the quality and brand.

Benzene is virtually impossible to find outside of highly specialized industrial applications these days. We've know for at least 60 years that is causes a leukemia like disease, and more recently, cancer in lab rats. 30 years ago, auto gasoline contained 15% Benzene, today it is in the very low parts per million range. It was also once a major component of common paint stripper. Not in the last 30 years. If you have some, I'd advise against using it. However, in the old days, we used to rinse our laboratory glassware and hands with it! I still advise against using it.

PEL (permissable exposure limit) for some common solvents, in parts per million:

Acetone 1000
MEK 200
Benzene 1
Xylene 200
Toluene 200
Methylene Chloride 12.5
Isopropyl Alcohol 400
Ethyl Alchhol (Absolute) 1000
Methyl Alcohol 200

Just a note, methyl alcohol (the active ingredient in windshield washer antifreeze for us Yankees) has a lower boiling point than MEK, and will evaporate a bit faster. However, it has a higher odor threshhold, and in my opinion a milder odor, so you could be exposed to more without noticing it.

MSDS's are not really meant to protect the user of the product, but rather the manufacturer against liability claims brought by their customers. Everything, including water, can kill you. I'm not at all impressed with in information on the typical MSDS..... it makes fairly common materials look deadly, and deadly materials look commonplace.

Everything should be treated with respect!

I get dry skin from exposure to MEK. Others have developed toxic reactions. Go figure!

I know airplane builders that have gone into anaphylactic shock when exposed to the amine curing agents in epoxy resins. Some people are sensitive to certain things. Not everyone is always sensitive to the same thing. That's why there are so many apparently diametrically opposed views on the safety and proper handling of certain chemicals!

I've made it 35+ years without a known side effect from way more exposure than I'd even like to admit to. I'm praying I can make it another 20 at least. Maybe just good genes, certainly not good sense.

Less is better. But I still don't panic when I smell the smell. Life has risks. Learn to manage them!
 
It laughs at latex gloves. I cleaned a plastic handled dental mouth mirror with it and layed it down to dry, when I turned back around, there was a line of white powder where the mouth mirror had been. Ouch.

Having said that, it'll clean off your hands better than anything else I have in the shop. It's kind of like acetone on steroids.

Jeff
 
safety first

Interesting thread, this. Responses range from the serious, to the lighthearted, reflecting the full gamut of attitudes toward safety. As a safety professional at a large and world-reknowned research facility, I see these attitudes every day, and it's a real struggle to get everyone on board the safety bandwagon. Fortunately, attitudes in the workplace toward safety have changed in recent years.

Unfortunately, outside the workplace, safety considerations often fly out the window for many reasons. We've all stood on the top step of the ladder, and d*** near fallen off. I'd encourage everyone to always remember what your objective is. Enjoy the build process, but return to bed at night breathing properly with all your body parts intact, so that you can come back tomorrow. Believe me, I've made all the mistakes, too.

Check your egos at the shop door, and read the d*** instructions! Take the time to work safely, and don't operate power tools when you're tired. Not only will you be safer, but the quality of your work will improve, and you'll be able to enjoy and share the fruits of your labor.

MEK is miraculous yet serious stuff, but as has been pointed out other products will accomplish what you want which are slightly less dangerous. I prefer acetone, but I have MEK, too. When working with solvents or other volatile organic compounds (VOCs), wear nitriles, protective eyewear, and most importantly, work in a well ventilated space. In some situations, respirators with charcoal filters, the type painters use, are appropriate.

Like the sergeant from Hill Street Blues used to say, let's be safe out there...

Sorry to preach, but I just couldn't pass on the opportunity to speak up on something that is so important to me.
 
william weesner said:
if you buy mineral spirits (paint thinner for oil also for parts cleaning)at lowes it says on the side of the can that it contains benzene and it is known to cause cancer (parks brand)22.00 for 5 gal
I should learn to take my own advise and not make general statements :D

Very true, it does list Benzene. The MSDS shows it at less than 10 ppm, which probably triggers the State of California reporting and labeling requirement. However, one of the major 100LL suppliers lists Benzene at levels up to 10,000 ppm, and I've seen an MSDS for unleaded auto gas list it up to 49,000 ppm. I don't believe that any of these come close to these levels, but again, the liability syndrome kicks in.....

Refinery technology being what it is, it's almost impossible to eliminate Benzene from any crude oil derived product. However, what I was referring to was the old formulations that contained Benzene in major percentages, like 35% in the old paint strippers. Does this mean that < 10 ppm is safe? Obviously not in California, and possibly no where at all. But then, how much do you breathe in when refueling your plane?

As I said before, lees exposure is always better, and it's all about managing risk.
 
chuck said:
You think that stuff is bad check this out:

http://www.dhmo.org/facts.html

This chemical is really bad stuff...
Yeah, I understand that it directly claims over 6000 lives per year!

Also seems to be particularly objectionable to aircraft owners:

Corrodes unprimed aluminum,
needs to be kept away from fuel systems,
destroys wood props, and
really can screw up a nice flying day!
 
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