BS 6387 Flame temperature and duration of test

The flame temperature used and the duration of the test shall be selected from the following categories:

category A 650 ± 40 °C for 3 h
category B 750 ± 40 °C for 3 h
category C 950 ± 40 °C for 3 h
category S 950 ± 40 °C for 20 min.