Mercuric Sulphide
From Cargo Handbook - the world's largest cargo transport guidelines website
A red or black powder, a form of mercury, usually packed in steel drums. Used as a pigment.
Highly toxic by ingestion, inhalation and skin absorption. Cases have been known of spontaneous ignition of drums of this commodity through exposure to sun heat. Under-deck stowage in a cool hold is advisable and safe if the drums have not previously been subjected to heat.