I searched and searched for HEPA filters for my Honeywell that did not emit the foul, headache causing odor and these are it. I purchased my Honeywell Air Purifier and plugged it in but was forced to stop using it almost immediately because of the terrible chemical odor that was being emitted into the room. In fact I almost returned it due to this problem but then I searched the internet and found that many people were having the same problem and it seemed to be coming from the HEPA filters that came with the Air Purifier. Since the ones that came with it are provided by Honeywell you would think they would be high quality and be the best at cleaning the air not contaminating it with even more terrible odors that cause terrible headaches, but this is not the case. After much searching and almost giving up I decided to give these a try and I am so glad I did, they seem to be doing a great job at cleaning the air and are not causing headaches and making me feel sick. We will see how they play out as time goes on, but so far so good, at least I can use my air purifier. The only issue I found is that the filters have a tendency to want to fall out of the designated spaces on the purifier, so I either have to lay the purifier down or quickly put the carbon filter over the HEPA filters and put the cover on or they fall out.