We recently filmed a video showing the difference between microfiber pillows and wool pillows in regards to how flammable each of them is. What you'll see in the video is that despite all the chemical flame retardants the polyfill is still very flammable. Wool, on the other hand has natural properties that make it much more flame resistant.
Another question worth considering what sort of flame-retardants are pillow manufacturers having to put in their pillows to reduce their flammability? And are they good for your health? In other posts we explore this question. In the meantime, please enjoy the video.