Hydraulic circuits. Hydransafe HFDU 46 lessens the serious risks presented by recourse to a mineral oil on the occasion of rupture of a hose or when a leak gives rise to oil mist, in the immediate vicinity of a flame, a part in the process of melting or a switch cupboard. Hydransafe HFDU 46 is recommended for hydraulic equipment operating in locations comprising a fire risk such as iron and steel works (coking plants, blast furnaces, continuous casting), mines, etc? Thanks to its biodegradability, it is especially recommended when there is a possibility of water contamination: offshore, mines?