Lye

Traditionally, it was obtained by using rainwater to leach wood ashes (which are highly soluble in water and strongly alkaline) of their potassium hydroxide (KOH).

[4] In Assam, north east India, extensive use is made of a type of lye called khar in Assamese and karwi in Boro which is obtained by filtering the ashes of various banana stems, roots and skin in their cooking and also for curing, as medicine and as a substitute for soap.

Lye made out of wood ashes is also used in the nixtamalization process of hominy corn by the tribes of the Eastern Woodlands in North America.

Sodium hydroxide is commonly the major constituent in commercial and industrial oven cleaners and clogged drain openers, due to its grease-dissolving abilities.

After several hours the chamber will contain a liquid with coffee-like appearance,[7][8][9] and the only solids that remain are very fragile bone hulls of mostly calcium phosphate, which can be mechanically crushed to a fine powder with very little force.

[13] A 3–10% solution of potassium hydroxide (KOH) gives a color change in some species of mushrooms: When a person has been exposed to lye, sources recommend immediate removal of contaminated clothing/materials, gently brushing/wiping excess off of skin, and then flushing the area of exposure with running water for 15–60 minutes as well as contacting emergency services.

[14] Personal protective equipment including safety glasses, chemical-resistant gloves, and adequate ventilation are required for the safe handling of lye.

Similar to the case of other corrosives, the containers should be labeled to indicate the potential danger of the contents and stored away from children, pets, heat, and moisture.

The majority of safety concerns with lye are also common with most corrosives, such as their potentially destructive effects on living tissues; examples are the skin, flesh, and the cornea.

Aluminium, magnesium, zinc, tin, chromium, brass and bronze all react with lye to produce hydrogen gas.