Brilliant green (dye)

Brilliant green (also known as zelyonka or zelenka) is one of the triarylmethane dyes. It is closely related to malachite green.

Uses
Brilliant green has been used to color silk and wool.

It is indicated for disinfection of fresh postoperative and post-traumatic scars, umbilical cord of newborns, abrasions, cuts, and other violations of the integrity of the skin, in the treatment of purulent-inflammatory processes of the skin - hordeolum ("barley"), meibomite, blepharitis, pyoderma, local furunculosis, carbunculosis, staphylococcal infection. It is applied externally, the drug is applied to the damaged surface, capturing the surrounding healthy tissue.

In Russia and Ukraine (and much of the rest of the former Soviet Union), the dilute alcoholic solution of brilliant green is sold as a topical antiseptic, also known under a Latin name solutio viridis nitentis spirituosa and the colloquial Russian name of zelyonka (, lit. 'green stuff' in Russian), which is zelenka  in Ukrainian.

A 1% solution in 60% alcohol can be used for treatment of skin. 0.5% solution is used for mucous membranes or for infants.

Brilliant green is a visible light-activated photocatalyst in organic synthesis.

Safety and toxicity
Brilliant green is effective against Gram-positive bacteria. The main advantage of brilliant green over the more common antiseptics such as iodine is that it does not irritate mucous membranes as harshly on accidental contact. Soviet medical doctrine deemed it "not for use on mucosa" and cautions that it can cause eye damage and ophthalmic chemical burns and burns to an eye, at least in the typical formulations produced for medical use.

Brilliant green induces vomiting when swallowed and is toxic when ingested. The compound may lead to serious injuries if it comes in contact with an eye, even resulting in bilateral blindness due to corneal opacification.

Politics
In Russia and sometimes in Ukraine, zelyonka has been used to physically attack political opponents. Since 2016, many opponents of the Russian government have been splashed with zelyonka, including Alexei Navalny, Igor Kalyapin, liberal activists, Nadya Tolokonnikova, Maria Alekhina, Lyudmila Ulitskaya, Ilya Varlamov and Mikhail Kasyanov.