Chinchillas are from the Andes Mountains where the air is clean and clear naturally, their lungs were not made to handle man-made perfumes or other chemical odors/compounds. Pneumonia is usually the eventual result of exposure to these man made odors. Your friend/roommate could easily kill your chinchillas by spraying chemicals, powders or using any other "man-made" items in the same room as your chin, such as, but not limited to, bath powder, air spray, sented candles, perfume, cleaning chemicals, bug spray, cat litter with an 'odor controller', and cedar wood chips, just to mention a few.
If you clean your chin's cage weekly, there should be no real noticeable odors
to most people. But, some people have sensitive noses. You might want to 'gently suggest' your roommate not go into the room where your chinchillas are kept and keep the door to that room closed, as not to offend your roommate's nose. If this does not work for your roommate, you might think of getting a new roommate OR finding your little ones a new home. (Sorry, but, as a breeder of chinchillas for 20+ years, I'm 150% for chinchillas.
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Keep us posted on what you decide to do. Hope all works out for the best (especially for the chinchillas).
Jo Ann