 For shipment purposes, this product is considered a ”dirty oil” product, and because viscosity drastically affects whether it is able to be pumped, shipping has unique requirements.Mazut is much like Number 6 Oil (Bunker C), and is part of the products left over after gasoline and lighter components are evaporated from the crude oil.The main difference between the different types of Mazut-100 is the content of sulphur.