Many consumers worry that discoloration of memory foam means that the foam has gone bad, become toxic, or will no longer perform like it used to. Do not be alarmed – while many consumers have these worries, the slight yellowing or discoloration of memory foam is natural and in no way corresponds with the quality or performance of the foam.
Generally, memory foam discoloration that is due to an oxidation process is permanent. This process often happens over time gradually and naturally. Though it can be baffling when one notices that a product’s color or appearance has been altered, in the case of memory foam, there is not much to worry about. Memory foam can still continue to function as it is meant to despite low levels of oxidation due to exposure to the environment that may cause discoloration.
In the case of noticing discolored or yellowed foam, remember that it is due to a natural reaction within the foam and that low levels of oxidation do not have negative consequences for the quality or performance of your favorite memory foam products.
It can become time to change your pillow when you see the outer cotton case yellow or stain, (washing approximately once a year) or if you exceed the three-year manufacturing warranty. At this point, it is best to change your pillow for hygienic reasons.