Cyclic Crude, Intermediate, and Gum and Wood Chemical Manufacturing This U.S. industry comprises establishments primarily engaged in one or more of the following: (1) distilling wood or gum into products, such as tall oil and wood distillates; (2) distilling coal tars; (3) manufacturing wood or gum chemicals, such as naval stores, natural tanning materials, charcoal briquettes, and charcoal (except activated); and (4) manufacturing cyclic crudes or cyclic intermediates (i.e., hydrocarbons, except aromatic petrochemicals) from refined petroleum or natural gas.