Their pants are not acid proof. (cue massive gasps of surprise)
It is not acceptable to complain to your lab's "Mother Superior" about ruining your $130 yoga pants after you spilled on yourself, especially when there is an entire rack of labcoats within arm's reach.
After filling out the requisite incident reports and packing you off to employee health, I will judge the everloving shite out of you.
ETA. I'm not unsympathetic to how terrible (and painful) acid burns can be, I just don't have much sympathy for anyone who thinks the university should compensate them for their now ruined overpriced yoga pants. Especially when that's what they'd rather address instead of dealing with what will likely be a nasty scar.