ALUMINUM TANKS:  fully charged with oxygen at 80°F to G.R.= 5000 psi to provide breathing for firefighters. The apparatuses have a have a safety factor of 2.5. One wonders, "Does that mean on temperature or pressure?" Check both cases.At that pressure the pressure relief valves of the tanks are set to blow if the tank pressure attains 16,400psi. If this tank is lost in a fire, at what temperature with the relief valve fail?