In some parts of the United States, methanol, instead of ethyl alcohol is used as a additive in gasoline to increase fuel efficiency. Methanol is a colorless liquid and when mixed with other liquids is almost unrecognizable to taste. Clinical Pharmacology Methanol is distinctive from many other toxins in that toxic effects after exposure may not be immediate. Peak plasma levels are seen 30-60 minutes after ingestion. Methanol can be readily absorbed via the skin, lungs or gastrointestinal tract.
Methanol is metabolized primarily in the liver.
Methanol is metabolized by hepatic alcohol dehydrogenase to yield formaldehyde. Formaldehyde is then quickly metabolized to formic acid contributing to the metabolic acidosis seen in methanol poisoning. As with ethylene glycol the major toxicity is not from the substance itself, but from the toxic metabolites. In the case of methanol the metabolite responsible for the detrimental effects is primarily formate. If hepatic THF levels are reduced, as in the case of most primates, the formate will accumulate producing metabolic acidosis .