what are the small black things that fall from top ceiling of my grill? I have quite an old cooker, and when I put foil paper in I notice little black things fall onto the foil from the top of the grill (I think broiling in US) compartment. Even when I don't cook if I put something in and hit the ceiling/gas heating element I can see these little black things fall.

I'm concerned it might go onto food and I'll eat them without knowing.  Do you know what these are likely to be? Is it a hazard, or maybe time to get a new grill?
This answer is in regard to an outdoor Weber grille.  According to the Weber grille people the black peelings are carbonized grease that accumulate when cooking and are not harmful. They might not be tasty though so I recommend a quick wipe to loosen the particles before cooking.  Again Weber suggests using aluminum foil to brush the top and I believe that is because aluminum is softer than steel and so won't scratch the surface.  Happy grilling!