Some mattress stores sell low cost / low quality visco mattresses. These are generally imported from China. They are compressed and vacuum packed for easy shipping. Polyurethane foam is made from oil. It can be any type of oil such as corn, soy bean or petroleum.
If a foam mattress has a very strong odor, chances are you are looking at questionable quality. Usually this smell does not completely ever go away. (I have had customers tell me nightmares how when they came home the first thing they smelled when opening the front door was their stinky mattress).
Our better quality mattresses all contain “biodegradable high density soy based foam. This is soy bean foam and is considered to be some of the finest foam available.
Don’t make the mistake of buying these low cost, low quality mattresses which are made in china. They may look pretty on the outside however don’t let appearance influence you. Give it the smell test!