Health

"Perc" comes from "perchloroethylene", an irregular and confusing name used only in industry. In more formal chemical nomenclature, the name might suggest the presence of a perchloryl group, which is not present. But the obvious abbreviation of TCE was already taken.

Tetrachloroethylene was the chemical responsible for toxicity and carcinogenicity in the W.R. Grace chemical waste dump made notorious by the book and film, A Civil Action. The solvent was used as a degreaser, if my info is correct. That's more or less what "dry" cleaning is -- cleaning with liquids other than water, and usually water-immiscible, which usually means oil-soluble. Great for removing oil and grease (like dissolves like), but hazardous.

https://en.wikipedia.org/wiki/Trichloroethylene#Cleaning_solvent
https://en.wikipedia.org/wiki/Tetrachloroethylene#Health_and_safety