Definition: a fear of chemicals or chemistry
I could figure this one out from the word structure, but here’s the interesting thing about this – this is always irrational, because everything is chemicals. We tend to think “chemical” means something artificial, created in a lab. But water is a chemical. Everything is a chemical.
It is not possible to be rationally chemophobic. To do do would be incompatible with living as a human. When people express chemophobia, they usually mean the artificial manipulation of materials and elements by humans by scary guys in white lab coats. Chemicals themselves are technical harmless.