I'm looking for a fic that I think was a gen fic, but I'm not sure about that. The Avengers were fighting some alien blob things of different colours and each coloured alien's ooze effected what it touched differently, like acid. Tony got hit in the face with some black ooze, blinding him, gagging and making it really hard to breathe. He might also might not have been able to hear as well as he should. The Avengers band around him while he panicks and they calm him down. They go back to the tower and have a group shower only to find that the black stuff can be dissolved in water.
I'm almost posative it was on archiveofourown.
Hope someone knows what this fic is, I would really like to read it again.