pf2e.fyi
From Pathfinder Treasure Vault (Remastered), which isn't enabled.

Corrosive Engravings

ITEM 5
Price 140 gp
Usage held in 1 hand
Bulk L

These tin sheets are bound in brass and show significant signs of erosion. The grimoire's title is acid-etched, and flipping between the sheets leaves your fingers covered in flecks of rust and powdery metal.

Activate (concentrate)
Frequency once per day

Effect If your next action is to cast an acid or poison spell that deals persistent damage, any creature who takes persistent damage from the spell is also Sickened 2 until the persistent damage ends. Using an action to retch can reduce the sickened value as normal, but it can't reduce the sickened value below 1 until the persistent damage ends.
Pathfinder Treasure Vault (Remastered)ORC