What is "pentachlorobenzene"

Pentachlorobenzene (PeCB) is a chemical compound with the molecular formula CHCl which is a chlorinated aromatic hydrocarbon. It consists of a benzene ring substituted with five chlorine atoms. PeCB was once used industrially for a variety of uses, but because of environmental concerns there are currently no large scale uses of PeCB. Pentachlorobenzene is a known persistent organic pollutants (POP), classified among the "dirty dozen" and banned globally by the Stockholm Convention on Persistent Organic Pollutants as of 2011.