Yes,i know that by pictures it is a problem to give an answer.but i assumed that maybe you familiar with the material that usually used for fan base,since you are chemists experts.
I gave the name of the brand,the plastic code,the weight and closeup,the kind off smell(combination of stinking shoes and wheel tyre)and the black color that it left behind on your hand if you touch it.
So,i was hoping that from your experience you could give me an answer.
From my experience bad smell always idicate bad material/recycle material/toxic material.
The fan seems to be good quality but this smell ruins everything.