Tamil Nadu Hooch Tragedy: Methanol Sourced Alcohol

Science (CSC) Health and Diseases

Context: More than 50 people have died in Tamil Nadu after consuming spurious liquor which contained methanol.

It is a commonly used term for poor quality alcohol, derived from Hoochinoo, a native Alaskan tribe that was known to produce very strong liquor.
Unlike branded liquor which is produced in factories with sophisticated equipment and rigorous quality control, hooch is made in much more crude settings.

All alcohol is produced using two basic processes: fermentation and distillation.
Fermentation:When heated, yeast reacts with sugar (from grain, fruits, sugarcane, etc.) to ferment and produce a mixture containing alcohol. This is an age-old process, used to create beverages like beer or wine.
Limitation: As fermentation continues, and alcohol levels rise, conditions in the mixture become toxic for the yeast. Eventually, no more fermentation can take place. Thus, to make anything stronger (above 14-18% ABC), beverages need to be distilled.
Distillation:This is the process of physically separating alcohol from a fermented mixture using evaporation and condensation.
Since different parts of the mixture have different boiling points, heating it up to the correct temperature makes it possible to separate only the alcohol from the water and other remnants. Distilled beverages, or spirits, are far more potent than any fermented beverage.

The fermented mixture which is distilled contains more than just consumable alcohol (ethanol). It also contains methanol, an industrial alcohol which is highly toxic for human beings.
Non-distilled alcoholic beverages like wine contain relatively harmless trace amounts of methanol. But during the distillation, both ethanol and methanol are concentrated. Thus, if done incorrectly, distillation can lead to an end product which contains high quantities of toxic methanol.

Methanol or methyl alcohol can cause impaired vision, high toxicity and metabolic acidosis, a condition in which the body produces excessive acid that cannot be flushed out by kidneys.
The treatment for this is to intravenously administer Fomepizole and ethanol. However, fomepizole can be expensive and unavailable in many parts of India.
In such cases, doctors administer a mixture of ethanol and water (1:1 ratio).
Ethanol inhibits methanol’s conversion into toxins and helps in flushing it out of the body either naturally or through dialysis.

Schedule I of the Manufacture, Storage and Import of Hazardous Chemical Rules 1989 includes methanol.
The Food Safety and Standards (Alcoholic Beverages) Regulations 2018 stipulate the maximum permissible quantity of methanol in different liquors.
For example, these values span a wide range including “absent” in coconut fenny, 50 grams per 100 litres in country liquor, etc.
The Indian Standard (IS 517) applies to how the quality of methanol is to be ascertained, and together with the Tamil Nadu Denatured Spirit, Methyl Alcohol, and Varnish (French Polish) Rules 1959, what signage, methanol packaging should carry

Once methanol is ingested, the body takes some time to completely eliminate it. There are two immediate ways to treat methanol poisoning.
One is to administer ethanol (of a pharmaceutical grade, by healthcare workers). Ethanol competes with methanol for the ADH enzymes. As a result, the methanol is kept from being metabolised to formaldehyde.
The other option is to administer an antidote called fomepizole, which slows the action of the ADH enzymes, causing the body to produce formaldehyde at a rate that the body can quickly excrete, preventing the deadlier effects from kicking in.