Pentachlorophenol

Source: pentachlorophenol.pdf (epa.gov)

It was primarily used as a wood preservative.  Pentachlorophenol is extremely toxic to humans from acute (short-term) ingestion and inhalation exposure.

During the late 1940s, pentachlorophenol (penta) was approved for use with wood crossties. Penta is an excellent wood preservative that is still in use in the wood utility pole industry. During the next decade, or so, penta was either added to creosote for ties (proving to be highly corrosive) or used as a standalone treatment by railroads in small quantities, in various methods of application, for wood ties (Cellon process, heavy oil carriers, etc.).

The practice of using penta for ties fell out of favor with RRs in the early 1960s.The principal use for pentachlorophenol is as a wood preservative; it is also used for the formulation of fungicidal and insecticidal solutions and for incorporation into other pesticide products. (1) Workers at wood treatment facilities and lumber mills are estimated to breathe in about 10.5 to 154 mg/ day, and workers who handle treated lumber can absorb about 35 mg/day through the skin. (1) Pentachlorophenol and its breakdown products can be measured in blood, urine, and tissues. (1)

How much is in the ground, air or dust and water?

How does it act in this environment? ‘

What does it do to the human body?

Acute inhalation exposures in humans have resulted in neurological, blood, and liver effects, and eye irritation.  Chronic (long-term) exposure to pentachlorophenol by inhalation in humans has resulted in effects on the respiratory tract, blood, kidney, liver, immune system, eyes, nose, and skin.  Human studies suggest an association between exposure to pentachlorophenol and cancer.