A: I didn’t know that humans spit acids
H: uhg we usually don’t, I think I ate something toxic
A: I see so the acid is used to neutralize the toxins
H: it really isn’t. Get back I’m gonna blow another chunk -- Anon Guest
[Offensensitivity warning: descriptions of regurgitation]
The Human digestive system is a mass of toxic substances in valved tubes. -- Gryxnu's Comparative Anatomy, 236 GalStand years before Human Admission into the Galactic Alliance.
221 Years before the Human Admission...
Human Bob evicted a stream of acid and other substances that Medik Gryxnu's livesuit registered as dangerous and informed on procedures to safely neutralise it. Step one included powdered cellulose. Step two was to seal off the area to prevent incidental contagion. Fortunately, a Medik's livesuit has extras that untrained lay people just don't have access to. Step three was where it started to get complicated.