Ohh acha. But I'm pretty sure I read something about milk in NCERT. So damn sure. Maybe in biomolecules with some acid is added. I'll check.
Gosh. NTA kya karega. btw this is NEET question so IDK. But NTA won't give anything outside NCERT so I think for now, formalin is for corpses. Thats it.
I have no clue where in NCERT it is. If you could give me the page no. it would be really really helpful .