New memory foam may initially have a slight odor; it is completely harmless and will dissipate over a short time with regular use, as our foam is made from a water-based material. If you do experience a slight odor when opening the box(es), it can be from the clear shipping wrap, this is to ensure your pillow(s) stays tightly compressed and clean until it arrives to your doorstep. We suggest you allow your pillow(s) to air out for 24 hours to eliminate the odor.