2 types de curves are taken into account, the curve of the ISO834 for « classic » fire, and the HCM « Oil plus » for fire occured by trucks highly combustible.
Level N0
•Minimum requirements to be met by any structure. CN 60
Level N1
•For the majority of fires. It ensures the structural strength during the time
for action relief. CN 120
Level N2
•It applies to facilities that must be preserved regardless of the fire intensity, during the time for evacuation shelters and relief
action. HCM 120
Level N3
It applies to facilities that must undergo the most violent fire during the time
maximum. CN 240 HCM 120
