This is confusing, because almost all the rooms in Science labs are fireproof from my experience so far, with some exceptions like the restrooms with TV’s, fridges and so on, there was carpet I think and a lot of other stuff where the fire could spread throughout the room. But otherwise, for example, I always burn all the fungal stuff when I encounter it and I don’t even close the door for that particular room, all fungal burns down and no fire spreading anyway.
What kind of underground labs are you talking about where you are doing laundry?
Give some screenshots if you can, it would help to clear what’s up.