In US. I recently tried to modify this air purifier (pictures) with the purchase of Activated Carbon Refill, 1200+ IAV Australian Charcoal. It was quite simple, I just replaced the activated carbon filter media with the charcoal and the pre-filter mesh holds it against the HEPA filter just fine. Other picture is partial fill before completion for better perspective if needed. Unfortunately even after running it for hours to try to ventilate, there has been a smell that is a dull sweet earthy smell thats constantly coming from the purifier that was not present before the charcoal placement. Smells in my opinion like some sort of aldehyde/ketone almost. The carbon bag has no odor in it. The company I bought the charcoal from stated that the carbon is pre-washed and ready to use out of the bag and that from their perspective 100% not an issue with the carbon, no need to heat the carbon or wash it again. I dont have a means to heat the carbon if there is something adsorbed to the carbon somehow being emitted anyway. My research online has not yielded much other than potentially some of the charcoal having gotten inside of the motor and creating odor? At a loss at this point and hopefully didnt ruin the air purifier if I go to remove the carbon. There is no ionizer. 

What emissions if any are being released from my air purifier with new activated carbon?