Open the windows of your home. Turn on the ceiling fans or place a window fan in the room to ventilate the area. Place the window fan so that it blows air outside the home. Open a window opposite the fan or in another room of your home to help with the ventilation process. Do this at least for 24 hours or until you no longer notice the smell.
Place the sofa outdoors for several hours a day for a few days. Do not leave it out overnight because you do not want the morning dew to collect on the fabric or have to deal with a soggy couch if it rains unexpectedly. The fresh air and sunlight helps to remove the factory odor.
Sprinkle baking soda over the sofa seat after removing the cushions, if it has any. Otherwise, just sprinkle it directly over the upholstery. Let it sit overnight and then vacuum the sofa thoroughly with a vacuum cleaner attachment.
Set out small bowls of vinegar in the room near the sofa. Make sure the bowls will not accidentally spill on the fabric. Vinegar is a natural deodorizer. If possible, shut the door of the room and leave it for a couple of days. Remove the bowls of vinegar and ventilate the room by opening the windows or running a fan. Once the vinegar smell dissipates after about 30 minutes, the sofa odor will be gone.