I'm a chemist, but don't want to experiment with this

April 12, 2011 6:09 PM

I just got grease from KFC on my shirt during my break while I was eating. I am actually at work in a lab right now. What is the best solvent to use to try to get out the grease stain?

I have access to all the common solvents in a lab, but don't want to start squirting all of them on my shirt, if I can first try some that are more likely to work.

Taking the shirt off to scrub or wash using detergent or soap is not an option, since this is my only shirt at work. But some not-too-toxic solvents can easily be applied.

posted by never.was.and.never.will.be. to Grab Bag (16 answers total)

If you still have the problem when you get home, over the weekend I used Goop to get out a very persistent grease stain on which nothing else worked. It's in a tub, and it's a hand soap that you also use on stains. It's magical.
posted by newpotato at 6:15 PM on April 12, 2011

Hexanes! But you know, do a spot test first on part of the shirt that isn't very visible in case it removes some of the dye... but it shouldn't.
posted by hooper4 at 6:15 PM on April 12, 2011

Chlorinated solvents work pretty well (tetrachloroethylene is dry cleaning fluid; methylene chloride is in some engine degreasers) but...well...also probable carcinogens.
posted by cabingirl at 6:21 PM on April 12, 2011

What is the fabric?
posted by malibustacey9999 at 6:34 PM on April 12, 2011

You don't want to use acetone. It will dissolve some synthetic fibers (e.g. cellulose triacetate AKA rayon).
posted by Chocolate Pickle at 6:51 PM on April 12, 2011

whatever you try to get the stain out.. once it is wet do not put it in the dryer! the stain will stay forever! once you start washing it just try as many things to get the stain out.. sometimes just rubbing detergent in the garment, oxyclean, etc. just try even scorching hot water over the stain. you need to break up the oil molecules in the stain to remove the grease from the clothing fibers.
posted by melizabeth at 6:54 PM on April 12, 2011 [1 favorite]

Oops. triacetate only dissolves in chloroform. But cellulose acetate will dissolve in acetone. Regardless, don't use acetone to remove the stain.
posted by Chocolate Pickle at 6:56 PM on April 12, 2011

Honestly, the best thing for this is to skip the solubility calculations and just use Dawn dish soap on the thing when you get home. Saturate the stain, let it stand or 15 minutes or so, then machine wash in cold and hang to dry so you can see how you did with the stain. (If it doesn't come out completely, the stain will look worse while it's wet, but it may be virtually unnoticeable once the shirt is dry. If you can, look at it in natural, fluorescent, and incandescent light to make sure it's -really- unnoticeable. ) You may need to repeat this 2 or even 3X, but it's going to work a lot better than mucking around with organic solvents, which may affect both the fibers of your clothing and whatever dye the fabric has.

(Not saying that the Goop stuff newpotato mentions isn't just as good or better. It's just that I always use Dawn for this, and it's generally ace. )
posted by palmcorder_yajna at 7:16 PM on April 12, 2011

Dish soap works pretty well to break up grease.
posted by illenion at 7:16 PM on April 12, 2011 [1 favorite]

Soap is probably best, though if you're curious I'd try hexane, isopropyl (rubbing) alcohol or ethanol.
posted by beepbeepboopboop at 7:19 PM on April 12, 2011

On non-preview:

It sounds like you're trying to deal with the stain at work so that you don't have to walk around looking like a goober for the rest of the day. This is an understandable goal, but I think it may be unrealistic. In my opinion, the solution (snicker) is to spend the rest of the day rocking a lab coat.
posted by palmcorder_yajna at 7:19 PM on April 12, 2011

I work in a lab with lots of hydrocarbons and triglycerides. The chlorinated solvents are the best bet and the safest for clothing. Our goto is dichloromethane, CH2Cl2. It may be a mild carcinogen, perhaps, but it`s a great solvent for removing oil and triglycerides from just about anything.

Failing that, a 1:1 mixture of hexane(s):acetone will work (and is a fair bit safer), but will also probably strip the dye out of the clothing. Check on a hidden corner first. Acetone can also be hell on plastics. If it's a synthetic fabric, this may cause problems.

Failing that, I'd try a light hydrocarbon, like pentane or hexane(s), with a light detergent. Or you could just use gu-gone, heptane with a bit of limonene in it.
posted by bonehead at 9:57 PM on April 12, 2011 [1 favorite]

Also, Mrs. bonehead's trick, which she learned from her machinist dad, is rub a bit of waterless handcleaner on it and launder normally. Works pretty well too.
posted by bonehead at 10:59 PM on April 12, 2011 [1 favorite]

Whenever I've had to deal with this problem at a restaurant, I've done the following:

(i) Find a restroom
(ii) Rub some liquid soap (or hard soap) into the grease spot for a minute or so
(iii) Wipe off as much of the soap as you can
(iv) Use a damp paper towel or some toilet paper on either side of the spot to get a bit more of the soap out.
(v) Dry with the electric hand dryer. This may require a certain amount of contortion.

Obviously this technique works best on areas of clothing that are easy to get to. For a collar or something you'd probably have to take the garment off.
posted by le morte de bea arthur at 1:56 AM on April 13, 2011

I've successfully used diethyl ether to dab out a large splotch of vacuum pump oil. Worked like a charm on a wool sweater, without any noticeable damage or color stripping.
posted by twoporedomain at 7:45 AM on April 13, 2011

Clip your ID badge onto your shirt so it hangs over the spot.
posted by CathyG at 8:21 AM on April 13, 2011