Fire stage

Heat (kW∙m−2)

Max temp (˚C)

Oxygen (%)

Equivalence

ratio ɸ

VCO/

Combustion

efficiency (%)

Fuel

Smoke

In

Out

Non-flaming

1a. Self-sustained smouldering

n.a.

450 - 800

25 - 85

20

0 - 20

-

0.1 - 1

50 - 90

1b. Oxidative, external radiation

-

300 - 600

20

20

-

1c. Anaerobic external radiation

-

100 - 500

0

0

-

Well-ventilated flaming

2. Well-ventilated flaming

0 - 60

350 - 650

50 - 500

20

0 - 20

<0.7

<0.05

>95

Under-ventilated flaming

3a. Low vent. room fire

0 - 30

300 - 600

50 - 500

15 - 20

5 - 10

>1.5

0.2 - 0.4

70 - 80

3b. Post-flashover

50 - 150

350 - 650

>600

<15

<5

>1.5

0.1 - 0.4

70 - 90