When a mattress is manufactured, it is pumped with gas to help push all of the cushioning and foam into its proper places. The gas that helps create your comfortable night's sleep also gives off that new mattress smell. Some people worry that the gases are toxic and could cause harm. Other people just do not like the smell a mattress has when purchased. No matter the reason, the solution is the same. Getting rid of the gas inside the mattress will eliminate the smell.
Remove the plastic wrapping from the mattress. A mattress is packaged in airtight cling film immediately after it is manufactured to ensure that it is sterile, dry and clean for the consumer. This has pros and cons. On the upside you know that no one has had dirty, sweaty hands on the place you plan to sleep. Unfortunately it also means that the mattress gases are trapped inside the airtight wrapping, leaving the mattress with that toxic "new mattress" smell.
Find an empty room in your home for the off-gassing process, which will remove the smell. You want a room that has good air circulation, with a window that can be left open at least ten hours per day or a room with a window unit air conditioner. The room also has to be off limits for about a week, so it needs to be a space that you will not miss. If you do not have an empty room, a garage or dry basement will also work. Leave the garage door open just an inch or two to allow in fresh air.
Run any fans, air conditioners and dehumidifiers you own in the degassing area. All of these will help keep the air moving and suck the gas and odours out of the room as they release from the mattress.
Lean the mattress against the wall at an angle. Each day, rotate the mattress so the opposite side is on top, getting more fresh air. This will allow the entire mattress to lose the new mattress smell evenly.
Allow the kids to jump on the mattress, or if you do not have kids, jump on it yourself. Jumping on the mattress will release the gas even more quickly. You can jump on the mattress the first day of degassing and as often as you'd like during the process. Just do not stay in the degassing area more than a few minutes, because you will be breathing in the gases you are trying to avoid.
Continue the degassing process at least four days but as long as two weeks if you would like. You can judge for yourself if the smell is going away.
After degassing, you should allow the area you used for the process to air out before using it for it's normal purpose. Just a day with an open window after the mattress has been moved will do the trick. Leave the blankets off the bed during the day for the first month or so even after degassing. This will allow any leftover gases to come out rather than becoming trapped under heavy comforters.
Do not degas your mattress outside. You may get rid of all the gas, but you will likely have a new problem--bugs.