"clean, quiet, safe" means the room is clean and quiet and safe.

switching e and t and removing comma gives

"clean, quite safe" means the room is clean and quite safe, i.e. not "safe" but "quite safe".

See here as well:
An English professor wrote on the board: A woman without her man is nothing.
The class was then asked to punctuate the sentence.
The men wrote: "A woman, without her man, is nothing."
The women wrote: "A woman: without her, man is nothing."