This industry comprises establishments primarily engaged in refining crude petroleum. Petroleum refining involves the transformation of crude oil by such processes as cracking and distillation.

This industry comprises establishments primarily engaged in manufacturing asphalt paving materials; manufacturing roofing rolls, sheets and shingles, by saturating mats and felts with purchased asphalt or bituminous materials; and manufacturing roofing cements and coatings.

This industry comprises establishments, not classified to any other industry, primarily engaged in manufacturing petroleum and coal products. Establishments primarily engaged in re-refining used products are included.