Coal tar is a black fluid of tremendously high viscosity when coal is carbonized,
Coal tar is among the by-products which manufactured coke or gasified to make coal gas.
Coal tars are compound and variable mixtures of phenols, polycyclic aromatic hydrocarbons (PAHs), and heterocyclic compounds.
Paracetamol is the only coal-tar derived analgesic which is still in use today, but industrial phenol is now usually synthesized from crude oil rather than coal tar.
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