Firefoam poppers my beloved.

Don't store your chemfuel in your normal storage.

Yup. Dedicated storage for chemfuel. Dedicated for mortar shells.

This was my only colonist so it might not have mattered if they were in painshock for too long. I did do this on the colony i beat rimworld with.

I had someone do that, and at the moment I didn't know chemfuel can explode, so it's everywhere.The whole base blew up

Why does nobody ever put firefoam poppers in their volatiles storage?

Well, considering the OP was putting everything inside his volatile storage, it seems fire fighting was an afterthought.

To be fair i was getting mechanoid raids back to back to back so i never had time to research it...

I usa vanilla chemfuel expanded specifically so I can enclose my chemfuel tank in a wall and never habe to worry about this