 Mazut may be used for heating houses in the former USSR and in countries of the Far East that do not have the facilities to blend or break it down into more conventional petro-chemicals.In the West, furnaces that burn mazut are commonly called "waste oil" heaters or "waste oil" furnaces.Mazut-100 is a fuel oil that is manufactured to GOST specifications, for example GOST 10585-75 (not active) or GOST 10585-2013 (active as per December 2019).