At the beginning of the test, 20 °C. (68 °F.).
At the end of the first 5 minutes, 538 °C. (1,000 °F.).
At the end of the first 10 minutes, 704 °C. (1,300 °F.).
At the end of the first 30 minutes, 843 °C. (1,550 °F.).
At the end of the first 60 minutes, 927 °C. (1,700 °F.).
For a further definition of the time-temperature curve, see Appendix I of the ASTM Standard E119, "Fire Tests of Building Construction and Materials".
46 C.F.R. §164.008-3