pyrogallol

Pyrogallol, also known as 1,2,3-trihydroxybenzene, is an aromatic phenol in which three hydroxyl groups are attached to a single benzene ring. The presence of three -OH groups makes it a relatively strong reducing agent and readily oxidizes to quinone-type structures. Pyrogallol occurs in trace amounts in certain plants, notably gall nuts, and has historically been produced commercially from gallic acid or tannin-rich materials through chemical processing such as pyrolysis or related transformations.

In terms of physical properties, pyrogallol is a white to off-white crystalline solid that melts near 40°C. It is soluble in water and in many polar organic solvents. The substance oxidizes in air, forming various colored oxidation products, and its stability is affected by light and heat.

Uses for pyrogallol have varied over time. It has been employed as a reducing agent in early photographic development and in certain tanning and dyeing processes. In modern contexts, it serves as an antioxidant and stabilizer in some polymers and as an intermediate in chemical syntheses for dyes, pharmaceuticals, and related compounds. It is also used as a reagent in analytical chemistry for redox-related assays.

Safety and handling are important considerations. Pyrogallol is toxic and can irritate the skin, eyes, and respiratory tract; it is regarded as a potential skin sensitizer. Appropriate personal protective equipment and ventilation are recommended, and exposure should be minimized. Proper storage away from oxidizing agents and heat helps limit unwanted reactions.