Ingesting as little as of pure<unk>  can cause permanent blindness by destruction of the optic nerve. is potentially fatal. The median lethal dose is , i.e., 1–2 mL/kg body weight of pure<unk> . The reference dose for<unk>  is 0.5 mg/kg in a day. Toxic effects begin hours after ingestion, and antidotes can often prevent permanent damage. Because of its similarities in both appearance and odor to<unk>  (the alcohol in beverages), it is difficult to differentiate between the two; such is also the case with denatured alcohol, adulterated liquors or very low quality alcoholic beverages.<unk>  is toxic by two mechanisms. First,<unk>  can be fatal due to effects on the central nervous system, acting as a central nervous system depressant in the same manner as<unk>  poisoning. Second, in a process of toxication, it is metabolised to formic acid (which is present as the formate ion) via formaldehyde in a process initiated by the enzyme alcohol dehydrogenase in the liver.<unk>  is converted to formaldehyde via alcohol dehydrogenase (ADH) and formaldehyde is converted to formic acid (formate) via aldehyde dehydrogenase (ALDH). The conversion to formate via ALDH proceeds completely, with no detectable formaldehyde remaining. Formate is toxic because it inhibits mitochondrial cytochrome c oxidase, causing hypoxia at the cellular level, and metabolic acidosis, among a variety of other metabolic disturbances. Outbreaks of<unk>  poisoning have occurred primarily due to contamination of drinking alcohol. This is more common in the developing world. In 2013 more than 1700 cases nonetheless occurred in the United States. Those affected are often adult men. Outcomes may be good with early treatment. Toxicity to<unk>  was described as early as 1856. Because of its toxic properties,<unk>  is frequently used as a denaturant additive for<unk>  manufactured for industrial uses. This addition of<unk>  exempts industrial<unk>  (commonly known as "denatured alcohol" or "methylated spirit") from liquor excise taxation in the US and some other countries. During the course of the COVID-19 pandemic, the U.S. Food and Drug Administration found a number of hand sanitizer products being sold that were labeled as containing<unk>  but tested positive for<unk>  contamination. Due to the toxic effects of<unk>  when absorbed through the skin or ingested, in contrast to the relatively safer<unk> , the FDA ordered recalls of such hand sanitizer products containing<unk> , and issued an import alert to stop these products from illegally entering the U.S. market.
Methanol
Ethylene glycol
Vinyl chloride
Triphenylchloroethylene
Chloroethane
Heptachlor
Chloroform
Beta-Hexachlorocyclohexane