[{"from": "human", "value": "Describe this molecule. [C][=Branch2][Ring1][Branch1][=C][Branch1][P][C][=Branch1][=N][=C][Branch1][=Branch2][C][=Branch1][Branch1][=C][Ring1][=Branch1][Cl][Cl][Cl][Cl][Cl][O]"}, {"from": "gpt", "value": "The molecule is a manufactured chemical that does not occur naturally. Pure pentachlorophenol exists as colorless crystals. Impure pentachlorophenol (the form usually found at hazardous waste sites) is dark gray to brown and exists as dust, beads, or flakes. Humans are usually exposed to impure pentachlorophenol (also called technical grade pentachlorophenol). Pentachlorophenol was widely used as a pesticide and wood preservative. Since 1984, the purchase and use of pentachlorophenol has been restricted to certified applicators. It is no longer available to the general public. It is still used industrially as a wood preservative for utility poles, railroad ties, and wharf pilings."}]