From the Skeptical OB Blog
Though methyl mercury and ethyl mercury might sound like they are very similar, one is poisonous and the other is not. How can that be? Consider the case of alcohol. Methyl alcohol (methanol), also known as wood alcohol, will lead to blindness or death if you drink it. Ethyl alcohol (ethanol) is the alcohol found in wine and spirits. Chemical structure is more important than the identity of the individual atoms that make up the compound.


An interesting analogy. However, ethanol is very poisonous - people still die from acute alcohol poisoning when they go on a bender, and alcohol is also poisonous in cumulative doses - alcohol abuse causes brain damage, cirrhosis of the liver, and blood vessel damage, just to name a few side effects. So perhaps it would be more correct for the Skeptical Ob to say that these two types of alcohol are poisonous in different ways.