MCHM: West Virgina Chemical Spill and 4-Methylcyclohexane methanol


Home / MCHM: West Virgina Chemical Spill and 4-Methylcyclohexane methanol
One of two isomers of 4-Methylcyclohexanemethanol Image built with Gabedit Open Source software

One of two isomers of 4-Methylcyclohexanemethanol
Image built by John Jaksich with Gabedit Open Source software

4-Methylcyclohexane methanol, the substance spilled into a West Virginia river, is somewhat of a mystery compound. The original patent filing of 1990 lists the substance as a frothing agent for coal. Used in conjunction with another co-frothing agent(s) and water, the agents basically clean the coal, producing a more pure finished product.

MSDS for 4-Methylcyclohexane methanol

The MSDS, or Material Safety Data Sheet,  for 4-Methylcyclohexane methanol gives very little information other than it has a high boiling point (386 degrees Fahrenheit which is approximately 160 degrees greater than water) and it may dissolve in water (specific gravity is  0.96 ).

Another data source gives a better picture of the molecule—a fat-to-water solubility ratio of approximately 2.0 (otherwise known as log P). To put the picture in some  perspective: ethanol has a log P value of -0.3 and gasoline (straight octane) has a log P value of approximately 5.0.

As one may surmise, the higher values denote greater fat solubility while the lower value denotes water miscibility.  On the other hand, the specific gravity (specific gravity is a measure of density) lets the reader know that with a value less than one, the substance will float on water (otherwise greater than one would denote the molecule is likely to sink). In other words, when mixing cooking oil and water one expects the oil to sink because the oil is heavier than water.

Coupling the log P with specific gravity—provides one the following rough description: The physical properties of the MCHM gives the molecule two disparate properties—water solubility and lipid (fat tissue) solubility. This compound possesses a total of eight carbon atoms that are responsible for fat solubility and it is alcohol group that gives the molecule water solubility.

MCHM: Synthetic Alcohol

The compound is a synthetic alcohol whose structure is anything but similar to common grain alcohol, ethanol. Ethanol is a two-carbon alcohol, while the substance in question is a ‘complex,’ eight carbon alcohol.

Another interesting property of the molecule is the boiling point—as stated above, it is greater than water. Why? There are a couple of reasons: The molecule is large (bigger than water) and because it tends to self-bond (through hydrogen bonding).

The patent disclosure of 1990 lists at least four different components other than the alcohol that could be used in the process. It should be understood that, presently, no one truly knows exactly what is in the river. All that is ‘said to have leaked’ is 4-methylcyclohexane methanol.




Because the MSDS does not inform us of the dangers, more research yielded an intriguing find from the National Institutes of Health (NIH) database.  The intriguing aspect of the bio-assay are the outliers of the assay. From some 86 tests for bio-activity, 8 returned an inconclusive result and 78 returned non-toxic result.

The compound was tested for toxicity of human biochemical pathways, but seemingly did not list how the molecule could gain access to those pathways.

A obvious rule of thumb would indicate that any foreign chemical substance in the presence of ‘life,’ could be a problem. However, the bio-assays performed seeming to have eluded common testing standards. MCHM, the substance deemed by West Virginia regulators as dangerous does appear to have an official designation as such.

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