Bedding may have a new upholstery smell when it is removed from the plastic wrap. The smell should diminish in two to three weeks. Increased air flow, such as opening a window in the room, will help to remove the odor. Alternatively, you may purchase sachets of charcoal to remove the odor. Odors that do not appear until several years after the mattress has been in a home are generally a result of being soiled over the years and long-term use. The upholstery of the mattress, like the fabric of clothing, is porous and traps odors when you cook or smoke at home. When this happens, it means your mattress is old and needs to be replaced.