Think the ally parts would be ok over coals ... the metal is good and thick , probably durable enough , but the plastic handle would probably suffer anywhere near flames !!!!
I don't know how durable the Silicon Sealing Ring that fits between the upper and lower body parts would be ... although MrsWhistle uses silicon cake "tins" and baking sheets ...
safe enough in the oven so must be tough enough s'pose ... P'haps you can find a cheap one at a boot fare or charity shop , then it wouldn'matter so much Ha ha ha !!!
Cheers Whistle