If you would like to know if the stains inside your Philips grill could be harmful, please find the answer in the following lines.
Are the stains inside my Philips grill harmful?
The stains inside the Philips grill cannot be harmful
Due to the high temperature in your grill, all bacteria are eliminated during standard use.
Bacteria are killed at 100°C and the temperature during grilling cycles are much higher than that.
Therefore, there is not any hazard situation (bacterial growth) possible: all stains inside your Philips grill are harmless.