The Occupational Safety and Health Administration (OSHA) regulates the mattress industry with their warranties.  According to OSHA, a mattress manufacturer can void their warranties if the customer has stained the mattress.  People are lead to believe that this regulation is about protecting workers from handling unsanitary mattresses.  This sounds legitimate on the surface but retailers handle stained mattresses almost on a daily basis.  As an added service for buying a mattress from a retail store, retailers will deliver the new mattress and remove the old mattress for free.  OSHA doesn't seem to care about the safety of mattress retailer's employees when they handle these old stained mattresses.  There seems to be some duplicity here.  Perhaps the mattress industry has lobbied OSHA through the International Sleep Products Association, the lobby group that represents large mattress manufacturers.