Like almost any new mattress, there’s a new-mattress smell. Even the natural and organic beds have a fresh-out-of-the-box smell, though it’s admittedly less pungent than the usual chemical off-gassing. The Aurora does have an off-gassing period. The website says 24 hours, but in our (ample) experience with new bed-in-a-box mattresses, it’s more like two days.