UNE-EN ISO 12922:2020

This document specifies the minimum requirements of unused fire-resistant and less flammable

hydraulic fluids for hydrostatic and hydrodynamic systems in general industrial applications. It is not

intended for use in aerospace or power-generation applications, where different requirements apply. It

provides guidance for suppliers and end users of these less hazardous fluids and to the manufacturers

of hydraulic equipment in which they are used.

Of the categories covered by ISO 6743-4, which classifies the different types of fluids used in hydraulic

applications, only the following are detailed in this document: HFAE, HFAS, HFB, HFC, HFDR and HFDU.

Types HFAE, HFAS, HFB, HFC and HFDR are fire-resistant fluids as defined by ISO 5598. Most HFDU

fluids, while displaying an improvement in combustion behaviour over mineral oil, fall outside this

definition and are more appropriately considered less flammable fluids.

NOTE For the purposes of this document, the terms % (m/m) and % (V/V) are used to represent,

respectively, the mass fraction and the volume faction of a material.