Advice? Bitumen paint on cast iron grill

Is this stuff likely to give off toxic or bad tasting fumes?

The supplied grids for the charcoal in my smoker have given up the ghost, but I've found a cast iron drain cover that would fit just about perfectly (I was thinking it would also help regulate the temperature). Problem is it's got bitumen paint on it, should I try to get the paint off it?

I suppose I could do a test burn & see how the smoke smells....

Thanks,

Rod