content: I know, late reply but yeah, form active duty now Air National Guard.  Used to work on F-16s, I'm sure you can guess what my AFSC was.  I ride a desk now in the guard however, enough flight line for me when active.  The military was definitely the first time I heard PPE but have heard the term in civilian industry as well, I think it's just not as prominent because as you said, you hear it a thousand times a day.  Especially when QA was being referenced.