ISO 2928:2021 specifies requirements for rubber hoses and rubber hose assemblies used for the transfer of liquefied petroleum gas (LPG) in the liquid or gaseous phase and natural gas and designed for use at working pressures ranging from vacuum to a maximum of 2,5 MPa (25 bar) within the temperature range −30 °C to +70 °C or, for low-temperature hoses (designated -LT), within the temperature range −50 °C to +70 °C.