Just because I recall a few things from chemistry lessons undergone during my education, Ive checked a few things:
Burning Injuries from white phosphorus.
Incandescent particles of WP cast off by a WP weapon's initial explosion can produce extensive, deep second and third degree burns. One reason why this occurs is the tendency of the element to stick to the skin. Phosphorus burns carry a greater risk of mortality than other forms of burns due to the absorption of phosphorus into the body through the burned area, resulting in liver, heart and kidney damage, and in some cases multiple organ failure.[70] These weapons are particularly dangerous to
exposed people because white phosphorus continues to burn unless deprived of oxygen or until it is completely consumed. In some cases,
burns are limited to areas of exposed skin because the smaller WP particles do not burn completely through personal clothing before being consumed.
For those raging flames:
http://www.youtube.com/watch?v=Oke8GinWDG8cca 3:20
As Teyl previously stated, the core of the effect is chemical raction. WP is not dangerous for "raging flames" but for the part when if you get stained (hope thats the right word) the flame cannot be put out until there is no oxygene that it could react with. Chemical protection wont work, because it is the heat that damages even chemical protection suite, but you have to be exposed to this chemical so it will burn throught your armor, skin and flesh until it absorbs all oxygene in reach or is absorbed by reaction. More to it, I can hardly imagine that there is additional fuel for the fire in elevator shft, besides concrete and steel...
Back to my case.
Would removing the burning (stained) parts of armor help to lower the damage?
How muc of my armor is stained by WP, and how difficult would it be to remove it? IDN how quickly can one remove chameleon suit...?