Instruction: Given a question and the related document, and generate the answer to the question based on the information provided in the document.

Input:
Question: Can you use it in the master bedroom when occupied ? Saying overnight ?
Document: That just stunk to high heaven and the only way I could even sleep in my bedroom where the mouse died somewhere was to run this air cleaner at full throttle. Finally, I did find the mouse and once it was tossed out, the air cleaner really helped get all the funk out of the room.The fan did die......... after a few months of use.
A small but powerful filtration system that does what it claims to do. Whether or not the unit remains placed in a higher or lower location is of no real consequence; this is really not so much of an issue. It doesn't matter where the GT50 is operated, but the size of the room/space does. I use this guy in our small bedroom.Having 3 pets on the bed can make for some "challenging" environments, to say the least.
I'm a heavy smoker, have it running everyday in my 15x20 bedroom but not in the evening.Have it on the lowest setting.Due to my experiance with a large ozone machine,($400) which works very good to sanitze any room or basement. I just use the lowest setting on the GT50 as to not smell the Ozone.Per Instruction w/the lg. machine your not suppose to be in the room when the Ozone running. I've had the GT50 now for about 5 to 6 wks.
There's no doubt this product works. Plug it in and less than an hour later you can notice a difference in the air quality in your home. It's an unusual, copy machine/lightning storm smell at first, but you stop noticing it after a while. It's like many other products with a plastic shell: it takes a little use before that new product smell disappears.I've used it in the bathroom, kitchen, bedroom, etc, always on the lowest setting, and it works beautifully.
Amazon must be knowingly complacent in the aggressive and active promotion of products that are hurting people. Ground-Level Ozone hurts people even when the O3 is virtually immeasurably low. Here's what the NIH (The National Institutes of Health, singular most important and highly regarded guardian of the world's says: [...]Compaines who facilitate (make or sell) occupied, indoor use of ozone generators damage, so, at least says the NIH to people using them.
(I have left the unit on overnight and still performs at the same level as when first turned on, but time will ultimately tell)Cons:- None to speak of at the time of this review. (But I will update as necessary)Conclusion:Of course the only way to confirm (or disprove) the pro's and con's of the GT50 is to purchase one for yourself. If you don't love this product after using it, you can always return it and be refunded.
So far it works great. I am  concerned however after reading the reviews. People are saying it well stop working after a little while. They have a 90 day waranty. Witch is short for the price. So now I have regrets about this purchase, but I guess time well tell.
I bought a laptop and it worked perfectly, but it really smelled strongly of cigarettes. I tried everything to get rid of it and searched the interwebs for advice. Well apparently the smell gets right up inside the heat sinks and it's impossible to get rid of...well almost impossible. I bought one of these things and left the laptop turned on in front of it overnight.
I bought this product to help eliminate pet odors in my house. I have 2 large dogs and a cat. I keep the dogs out of the main house  but live in a humid climate so odors tend to permeate and linger. This product works great. Eliminates odors immediately. I also am painting the nursery and used this overnight to help with the paint fumes and it did exactly that.
Vacuumed the carpet and it smells even better, the whole upstairs smells fresh just from 1/4 turn of this little green machine. I noticed a reviewer saying that the machine had a buzzing sound when he turned it on, I had the same problem and thought I may have broken it, but I unplugged it, gave it a few taps on the back where the air opening is and plugged it back in and the buzzing sound went away and its working fine.
Answer: I would check to ensure the people staying in the room do not have a reaction towards ozone air purifiers. I would tend to lean towards using while someone is not in the room.  If you have plastic in the room over time the ozone can deteriorate the plastic as well. Some people get a feeling of something caught in their throats as a reaction towards ozone.  Hope this answers you question and use at your own caution.