Methanol (wood alcohol) poisoning occurs in patients who ingest methylated spirits or methanol-containing antifreeze. It is rapidly absorbed from the gastrointestinal tract and is metabolized and excreted at approximately 20% of the rate of ethanol. The toxic range is thought to be 60–250 mL, although as little as 15 mL has caused death. Alcohol dehydrogenase metabolizes methanol to formaldehyde and formic acid, which is responsible for ocular toxicity (diminished light sensation or frank blindness), and anion gap metabolic acidosis; these are the principal symptoms of intoxication. Other symptoms include nausea, vomiting, headache, seizures, and coma. GC-MS is used to measure blood methanol levels, with a peak level greater than 50 mg/dL considered toxic. In addition, serum osmolality levels are increased to levels greater than 300 mOsm. Methanol (or ethylene glycol) poisoning should be considered in acutely ill patients with hyperosmolarity, metabolic acidosis, and increased anion gap.