Most antifreeze are prepared by mixing distilled water with some kind of alcohol like Ethylene Glycol, Methanol, Propylene glycol (mainly ethylene glycol). Ethylene glycol is known to be a sweet agent. The major cause of poisoning due to ethylene glycol are its metabolites - glycolic acid and oxalic acid. The symptoms of ethylene glycol poisoning generally follow a 3 step progression (in severe poisoning it may be different) Stage 1 (30 min - 12 hours) mainly neurological and GI symptoms - intoxication, dizziness, headaches, incoordination of muscle movements, nystagmus (involuntary fine eye movement), sometimes slurred speech, and confusion. There may be nausea and vomiting. Stage 2 (12 to 36 hours) may present with increased heart rate, high blood pressure, hyperventilation (rapid deep breathing) and metabolic acidosis (arterial blood gas sample and electrolytes are needed to assess this). There may be hypocalcemia (reduced Ca in blood), overactive muscle reflexes and muscle spasms and congestive heart failure may occur. Stage 3 (24 to 72 hours) - In severe cases, kidney failure may occur. Symptoms include low back pain and decreased or absent production of urine. If kidney failure occurs it is usually reversible, although variable duration of supportive care including hemodialysis may be required before kidney function is restored.