what makes the rubbery bits on a fridge/freezer black and mouldy?

[juicychops]

as thats pretty much what colour the rubbery bits on my fridge freezer is. its not hygenic and its pretty gross but does it mean there is actually something wrong with the fridge/freezer? like air getting into it or something? or does it just need regular cleaning?

I always thought it was damp/condensation. My fridge and freezer have it, but I do think my seals need replacing.

Bumping anyway for a more knowledgable answer.

thanks for your response solo

Actually, I'm sure Kim and Aggie dealt withy this problem once and they didn't mention seals must need replacing so maybe it's just a condensation problem after all.