Chemical spill in West Virginia: what IS that stuff?

A few days ago a company called Freedom Industries spilled a massive amount of a licorice-scented compound called 4-methylcyclohexane methanol into the Elk River, contaminating local water supplies and forcing authorities to turn off the taps until they can determine the extent of the problem. For folks who live in the area, this must be very frustrating — all they’ve been told is that they can’t drink the water and they don’t know when it will be back online, so the bottled water sold out overnight.

The spill has a lot of people wondering: what exactly IS 4-methylcyclohexane methanol (I’ll call it 4-MCMH) and how dangerous is it? Unfortunately the toxicology of 4-MCMH has been poorly studied, so neither I nor the federal gov can be sure exactly how dangerous it is. But let’s see how much we can figure out by looking at the structure of the molecule and thinking about what it’s likely to do inside the body. And as always I’ll try and make this as simple and non-scientist friendly as possible in keeping with the spirit of this blog.

So here’s the structure, courtesy of the wiki:File:MCHMstructure.png

Now this is drawn in 2D, but an actual molecule is a 3D structure. All of these carbons are single-bonded which means each of them is bonded to four other atoms. When a carbon is bonded to four other atoms those bonds tend to be arranged in a tetrahedral shape like this:

You can explain this tetrahedral shape using a model called molecular orbital theory, which mathematically describes the structure and properties of molecules in terms of quantum mechanics, but that gets very complicated. An easier way to explain why a carbon atom has a shape like this is through a simpler (though completely non-mathematical) model called VSEPR. The idea is like this. A bond between atoms is a pair of shared electrons, right? And electrons are negatively charged, so they repel each other. Therefore bonds to an atom are going to arrange themselves in such a way they are as far apart from each other as possible. A carbon atom with four bonds will therefore tend to have the shape shown above — because that maximizes the distance between all four bonds.

So if you take 4-MCMH and look at it in 3D, you’d find each of the carbon atoms in it would be at the center of a tetrahedron like the one above, which means that six-carbon ring would look something like this:

File:Cyclohexane-chair-colour-coded-3D-balls.png

If that’s what it looks like how come we don’t draw it like that? Well, fact of the matter is most chemists are really crappy artists. We’re the kind of folks who did just fine in calculus and o-chem but failed that stupid art class, you know. So by convention all chemical structures in chemistry are drawn in 2D because otherwise most of us wouldn’t be able to draw them. When we look at a chemical structure drawn in 2D we automatically mentally convert it into 3D — we just can’t draw them like that because we suck at art (unless you give us a computer that can draw for us). Anyhow.

What can we figure out from the chemical structure? Well, we know that water is very polar, meaning electron density in water molecules is very unevenly distributed. (See my earlier post about crack cocaine if you don’t remember why that is). Therefore as a general rule of thumb water is good at dissolving things that a) have a charge on them or b) are very polar. This molecule DOES have a polar OH group so that should help. But the area of the molecule that’s polar is just a small fraction of the area that’s plain old hydrocarbon which is very nonpolar. So you would expect it would dissolve quite poorly in water. You can probably get it into water at low concentrations (“appreciable” is the word in the MSDS, which is sort of vague) but it’s definitely not a very water-friendly compound. It’s also less dense than water so it will tend to float and form a separate layer on top.

You’d also expect the molecule should not be brightly colored. Carbon-based or organic molecules as a general rule of thumb are usually brightly colored if they contain either a) extensive alternating single-double bonds or b) a metal ion with a bunch of other junk stuck onto it. (See previous posts for more on why that is.) This molecule doesn’t have either of those things, and so as you’d expect it’s colorless. Some of the news reports said something about a green color in the water, which if true bothers me a little. (More on that in a minute.)

Is it dangerous? Well, like most organic solvents it’s flammable, but as you’d expect it’s a lot less volatile than other organic solvents like acetone or hexane. As a general rule of thumb, the bigger and/or more polar the molecule the less volatile it will be. That polar OH group on this critter can form weak bonds with other OH groups called hydrogen bonds and that will help to hold them together so they don’t evaporate as readily. Bu what we really want to know is what it does to humans, animals and plants. Unfortunately that’s a lot tougher to figure out.

First off, this chemical is NOT highly reactive, and we can tell that based on the structure. It should not react with either proteins or DNA. Since its water solubility is low, it will probably be pretty good at getting into fatty adipose tissue; it’s going to be pretty fat-soluble. Your liver will probably try to oxidize it to make it more water-soluble, e.g. by converting that H2C-OH group to a COOH group. A COOH group is acidic so it can lose the H and end up with a negative charge, e.g. COO-, which is WAY more water soluble than the OH group because it’s negatively charged now. It’s possible your liver will do other stuff to it as well. Once your liver has altered it a bit it will probably leave your body by way of your urine.

OK, fine. So this doesn’t look too dangerous. But we still don’t know for sure for two reasons. First of all, there are many thousands of proteins in your body. We don’t know what all of them are, and we don’t know what all of them do. There’s always a possibility a compound has just the right shape to stick to Unknown Protein X and thereby cause Dangerous Side Effect Y. Second, it’s always possible your liver will do something weird to this molecule and thereby make it more toxic. I can’t see anything obvious your liver could do to 4-MCHM to make it into a problem but you never know.

The upshot is you can’t tell for sure from a molecule’s structure how toxic it will be. You can spot obvious problem molecules (stuff that will UNDOUBTEDLY be toxic because it’s highly reactive in certain ways), but just because a molecule has no obvious problems doesn’t mean you’re in the clear. You have to do some experiments before you can be absolutely sure, which is how toxicologists and many other biologists make a living.

So what kind of data do we have? Unfortunately not much. This isn’t a widely-used chemical so the folks at FDA and EPA haven’t devoted much attention to it. The LD50 in rats — the amount it takes to kill 50 percent of a population of rats (and yeah, I know, that sounds like a not-very-nice experiment, but it’s one of those necessary things that toxicologists do) is 825 milligrams per kilogram of body weight. Assuming its toxicity in humans is similar, you’d have to drink a lot of this stuff to kill yourself.

The MSDS also lists the no-observed effect concentration in fathead minnows as 25 milligrams per liter (aka ~25 ppm), meaning that concentrations below that show no obvious effects in minnows and such. Now this is a possible problem. I don’t know how much of this stuff got dumped in the river. If we’re talking about a whole tankload, then you could potentially have situations where concentrations in specific spots or areas temporarily shoot high enough to hurt some fish and/or other aquatic organisms. (Fish don’t like swimming around in concentrated organic solvent any more than the rest of us.) But the environmental damage should not be broad or long-lasting because this stuff will break down in the environment. (Once it’s been diluted to low concentrations, bacteria will start munching it for one thing.)

There doesn’t seem to be any data on carcinogenicity. The MSDS says that prolonged exposure may cause a skin rash, and as always when in doubt rubbing it in your eyes is probably not such a great idea.

So to summarize I’d say this (in my decidedly non-medical, non-expert capacity). Don’t drink the water, but if I were me I wouldn’t panic, either. I’ve spilled far more dangerous chemicals on myself and I’m still here. You’re probably in much more danger handling gasoline than handling this stuff, and all of us handle gasoline on a regular basis. (Gasoline DOES contain a little benzene, which is both volatile and a known carcinogen.) ON THE OTHER HAND, in the absence of a detailed toxicological profile I would refrain from drinking or bathing in said water because as discussed we don’t know for sure until the appropriate toxicological studies have been done, and there’s no point being a guinea pig.

The one thing that bothers me a little is this. Like most industrial chemicals this probably isn’t very pure. In the pharmaceutical/biotech industry, when we make a drug for sale or use in clinical trials, we make it about as pure as it can get. And in my subfield of analytical chemistry, I buy & work with very pure reagents because I’m trying to figure out what’s present in a sample and how much of it, so I need to minimize background/contamination, and I can get VERY anal about that, let me tell you. But large-volume industrial chemicals are a different story. Why bother purifying something if you’re just using it to wash coal? come on.

So there could very well be other stuff in there besides 4-MCMH, and it’s always possible there are impurities more nefarious than 4-MCMH itself. As I said, this talk about blue-green water puzzles me because 4-MCMH is colorless, so it’s definitely NOT the 4-MCMH that’s responsible for the color. At least one news report I saw distinctly said the water had turned blue-green. (NOTE: See update/clarification at bottom of post). Perhaps Freedom Industries could clarify. What else is in there? a lot of folks in West Virginia would sort of like to know.

Oh, and I guess the final moral of the story would be this. Don’t situate your chemical plant on the river upstream from a major water treatment plant, especially if you’re making a chemical for which no detailed toxicological profile exists, because if you DO spill something it will make a lot of people very miserable. So no, that’s not really a bright idea…

Update: A commenter pointed out that the Elk River is apparently always blue-green this time of year thanks to algae, so the blue-green “stain” described by the New York Daily News could be normal and have nothing to do with the spill.

31 thoughts on “Chemical spill in West Virginia: what IS that stuff?

  1. Could the “blue-green” color be the oil sheen resulting from the different refractive indices of standing water and a thin film of organic on top? In my experience, impure organics are usually yellow/tan to brown. Even as an impurity, blue and green compounds seem unlikely, unless it was intentionally dyed. Otherwise, chromium or copper salts?

  2. My instinct is that a slightly polar cyclohexane derivative is going to be only a little safer than cyclohexane itself. I know *I* would not drink water affected by the spill. I might possibly bathe in it after suitable filtration, however.

    As for the hypothetical impurity, there isn’t much to go on, especially as the solvent had been used, right? A contaminant would be likely to have similar polarity to MCMH, although if the spill was from a leak toward the bottom of the tank, even that seemingly obvious notion could be wrong.

    I appreciate your conclusion. The Right-to-Know laws were a big step toward improving public safety in that they forced industrial transparency, but information is not enough in and of itself. Common sense must be applied and action must be taken.

      • You and me both. I saw one story implying the solvent was used, but most articles are vague on this point. We’ll get clarification once the Federal investigation concludes, I suppose..

        I haven’t written to Freedom Industries myself, but I see they do have a ‘contact us’ option on their web page, if you can’t wait🙂

  3. The bluegreen color of the Elk River is constant summer thru winter. The color has nothing to do with the chemical spill!! I am lifelong resident of WV, i have fished and boted on the Elk
    River from its source in thr mountains of WV, to its confluence with the Kanawha in Charleston
    WV. Anyone familiar with this stream knows this!! It is more likely algae coloration due to
    poluution from farmlands and septics systems along its entireity. From Sutton dam to its source in Webster county,this stream supports a thriving population of brown and rainbow trout which reproduce naturally.

  4. Very nice paper. Thanks.
    Too bad the 3D view of cyclohexane is not labeled as such, even though it exemplifies the “axial” and “equatorial” positions of the hydrogen atoms. A 3D view of 4-MCMH would have shown how messy it is to deal with 3D views and why 2D views are so much simpler.

    • It will definitely not get converted to benzene. there is no biochemical pathway that could convert it to benzene. Both benzene and this compound have a six-carbon ring, but the six-carbon ring in benzene is all double-bonded carbons, which gives it some very different chemistry. look at the structure of benzene to see what I mean:

      http://en.wikipedia.org/wiki/File:Benzene-2D-full.svg

      Like I said, I’m not terribly worried about this compound itself (although as always when in doubt do a tox study). What would worry me more would be other stuff in there, particularly if it’s used solvent.

    • Not that you asked me, but my opinion would be it would break down into other cyclohexane derivatives. Even if MCMH somehow went through sequential dehydration reactions (unlikely), that would only result in two double bonds on the hexane ring, whereas benzene has three.

      Set MCMH on fire or crack it, maybe then you could form a little benzene.

  5. I was wondering what analytical technique you would use to measure the amount of 4-MCMH. I’m studying analytical chem now, and I am curious.

    • That’s going to be either GC or LC, but given the relatively low boiling point of MCMH, probably GC with GC/MS backup to ensure the peak isn’t confounded with other species..

      Which is good, because LC also needs qualitative confirmation and the development of techniques to do so remains in disarray.

      • This is actually a reply to your reply (there wasn’t another reply button that I saw). I suspect the upper temperature limit cited in the EPA method is due to the columns (GC columns will denature if they are overheated, that is to say, the column coatings degrade). One can obtain columns that have higher maximum temperature ratings, but often at higher expense and changes in separation efficiency.

        Anyway, your EPA method looks to be primarily for VOCs, and you are right, with a BP of 202 C, MCMH is not a VOC. All this reminds me that equipment suppliers are often great sources of information. Any of the column suppliers listed in your EPA method could probably give you a good answer about what column and method to use for GC analysis of MCMH. If you have an interest in pursuing that line, I would suggest starting with either Agilent or Restek. Oh wow, in fact, the Restek web site has a blog post up on this very topic!

    • If I were me…the details of the method will depend on the matrix, but for a quantitative assay I would do something like this. If it’s in air, I would collect with an adsorption tube then desorb with an appropriate solvent and run on GC with flame ionization detection(FID). If it’s in plasma or urine or river water, I would extract with organic solvent then run on GC. Presumably in urine you would be looking primarily for the metabolite (GC-MS would be useful here). For environmental analysis, there are very often EPA-approved methods that have already been validated and so those are typically what are used. I don’t know whether there’s actually an EPA-approved method for this compound though…doesn’t seem very likely since EPA doesn’t seem to have paid this particular compound very much attention.

  6. I learned last night that the use for this chemical is to “wash” coal ..pretty word that we would all like to do ourselves….but what wash means in the coal industry is to coat low grade coal so that it will burn hotter therefore sell more coal….is that the purpose of this chemical?

    • My understanding is that the MCMH wash separates the coal from any inorgranics mixed with it: rocks, dirt, that sort of thing. That’s totally from media stories, though.

      While it makes sense to me that a process step to do this would be needful,I have no expertise in the coal industry, being more interested in polymers and all.

  7. My understanding is the Tank Farm was part of an old refinery built either in WWII or slightly before. The Tanks are single-walled as per the practice of that day, with external secondary concrete block wall confinement structure added later. My understanding is the secondary structure failed as well as the Tank itself.

    The Tank Farm predates the Water Treatment Plant by many decades.

  8. Hi, I’m a resident of the Kanawha Valley in WV and have been affected by the chemical spill. I’ve been wondering why reports have not been available from chemists who can break down the properties of this chemical the way you have here. Much appreciated that you took the time to do it. In light of the new information about what’s actually in the water (Crude MCHM, which contains 6-7 ingredients not found in 4-MCHM, and PPH), could you provide any additional information? I found myself really wishing I was a chemist as I reviewed the MSDS – http://online.wsj.com/public/resources/documents/Eastman.pdf. I also researched some about the possibility of the blue-green tint resulting from interaction with copper pipes. The MSDS states that Crude MCHM is “incompatable” with “strong oxidizing agents” (chlorine, fluorine?). Our water heater contained a blue-green, gelatinous sludge when we drained it, and I’m curious if copper oxidation or some other chemical reaction might be responsible. Thanks again for your insights!

  9. I am with Lynn. I tried to determine the breakdown for MCHM in water. The MCHM was varied concentrations and the water had free chlorine at 2 PPM and Fouride at 4 PPM. I am confident that it will not react with PVC pipes (only acetones, keytones, or esters). However, much of the public water suppy is cast iron with significant corrosion (iron ready to go into solution), and trace sediment accumulated in the system. All these unkowns are just food for thought, however the free chlorine and flouride are constant. From a layman’s view that was good at chemistry 20 years ago but hasn’t looked at it since, I can’t see any immediate problems. I see it remaining stable (not breaking down) while in the public water supply, just continually being diluted. Once in a sewer system or in nature, I would guess that the alcohol will be metabolized by microbes and broken down into simple sugars.

  10. Dear Puff:
    Thanks for your post. You say “I guess the final moral of the story would be this. Don’t situate your chemical plant on the river upstream from a major water treatment plant”. But suppose this plant was relocated just downstream of the West Virginia American Water’s intake in Charleston. Would that have solved the problem? No.

    It would help the problem, through dilution, but not solve it. There are hundreds of cities and many millions of water customers downstream of Charleston along the Kanawha, Ohio, and Mississippi Rivers. See http://www.wvgazette.com/News/201401140162 for discussion of how Cincinnati and many other communities shut off their water intakes as the MCHM spill flowed by.

    I would say the morals are: inspect storage tanks frequently, maintain a Department of Environmental Protection that is not beholden to industry, and do testing on chemicals that will be widely used so that we know their toxicity, in advance of a major spill.

    PS: Freedom Industries has transferred the MCHM out of Charleston to a Rosebud Mining facility somewhere in Armstrong County, upstream of my water intake here in Pittsburgh, so I am now nervous about this.

  11. Just wanted to add that I’ve searched the net unsuccessfully for this answer and short of going out and reading chemistry books, your knowledge seemed the best next step🙂 Thanks in advance!

  12. Loved your blog. You make o Chem easy to understand and memorable for us simpletons. I liked the one especially about acetylcholine esterase and the guy who discovered tabun.🙂

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