How Do You Describe the Amtrak smell?

Back on that Northeast Regional jam and there is truly nothing on this planet like the smell of an Amtrak train. What is that smell?!? Gimme your best adjectives and guesses.
  1. Slightly metallic, kinda moldy, but weirdly sterile?
    Like am I breathing completely disgusting air or is this completely clean air? Also it's stale and dry but kind of smells wet? Anyways, that's my assessment.
  2. Like the inside of a clean shoe, a generic windex spray, and the lobby of your doctors office.
    Suggested by   @ameliaville