There are many natural materials which produce a strong odor, no different to many synthetic materials. The smell of a substance is not related to the danger it might pose – some very dangerous chemicals (like Carbon monoxide) are odorless to humans.

The VOC off-gassing people worry about stands for Volatile Organic Compounds.
So - technically - just because something is organic doesn't make it safe.
This is why every component used in our mattresses is tested and certified chemically safe by Oeko-Tex Standard 100.