Another quality-control anecdote, just for you folks who complain about having to control dust on film or in a darkroom: In the Pharmaceutical plant next door, when they suit up for production in the
cleanroom, nobody can enter or exit until the end of the entire run, even if it takes 12 hrs - no batrhroom or lunch breaks, or the entire batch gets discarded and they clean the lab from scratch.
Each factory floors has huge HEPA dust hoods to scrub the air. Before production, the quality guys
come in, put on a brand new pair of white gloves and run their finger on the inside rim of the dust
hood. If the glove shows any stain,dirt, or dust at all, you're fired.