Abstract: Non-carcinogenic bright stock extracts and/or deasphalted oils are produced from reduced hydrocarbon feedstocks. Such non-carcinogenic products are produced by establishing a functional relationship between mutagenicity index and a physical property correlative of hydrocarbon type for the bright stock extract or deasphalted oil and determining a critical physical property level which, when achieved, results in a product having a mutagenicity index of less than about 1.0. Process conditions are established so that a product stream achieving the desired physical property level can be produced. Non-carcinogenic bright stock extracts and/or deasphalted oils are then processed utilizing the conditions so established. A bright stock extract and a deasphalted oil substantially free from mutagenic activity, as well as processes for their production are also provided herein.

Abstract: Non-carcinogenic bright stock extracts and/or deasphalted oils are produced from reduced hydrocarbon feedstocks. Such non-carcinogenic products are produced by establishing a functional relationship between mutagenicity index and a physical property correlative of hydrocarbon type for the bright stock extract or deasphalted oil and determining a critical physical property level which, when achieved, results in a product having a mutagenicity index of less than about 1.0. Process conditions are established so that a product stream achieving the desired physical property level can be produced. Non-carcinogenic bright stock extracts and/or deasphalted oils are then processed utilizing the conditions so established. A bright stock extract and a deasphalted oil substantilly free from mutagenic activity, as well as processes for their production are also provided herein.