HOW STRONG ARE PVC WINDOWS AGAINST FIRE?

PVC windows like other organic materials such as plastic, wood, textile etc., used in buildings will burn when exposed to fire.  However, PVC window will extinguish on their own in other words they will no longer burn once the source of fire is removed. PVC windows have fire safety features due to their high chlorine content.  They are hard to blaze up and their heat generation is relatively low.