Dye in Vaccinia (smallpox)
Synonyms: diamond green, malachite green G,
C.I. 42040, C.I. basic green 1
Toxicology: May be harmful by inhalation, ingestion
or through skin contract. May act as an iffitant.
Harmful by inhalation, and contact with skin and if
swallowed
Protection: safety glasses. Do not breathe
dust.
http://physchem.ox.ac.uk/MSDS/BR/brilliant_green.html
Serves no other purpose in vaccines than for looks.