Conventional mattresses are filled with synthetic materials. For example, most mattresses contain polyurethane foam. Polyurethane foam constantly breaks down and releases chemicals, which is called off-gassing. Polyurethane foam is made from chemicals that are known carcinogens.
Other toxic chemicals that can be found in conventional mattresses are PBDEs (polybrominated diphenyl ethers) or boric acid. These are used in mattresses as a flame retardant. PBDEs have been shown to have health effects in animals and are so toxic that Europe is phasing out the use of them completely!
Mattress materials are not regulated or rated for safety, but doctors told us that the ideal mattress should use natural, non toxic materials since we spend about one-third of our life lying in bed. Many sleepers report a sensitivity to the materials commonly used in mattresses. Their complaints range from headaches and rashes to more serious issues.
There are four basic types of materials used in making mattresses: steel springs, foam (memory, poly, latex and soy), cover materials (cotton, polyester, bamboo) and plastic/canvas in air and water beds. Foam is the common ingredient used in every type of mattress. Softer foams are used in the cover and in the top layers of the mattress for cushioning. Firmer foams are used on the sides and either beneath the spring unit or in place of the spring unit.
Most foam is petrochemical based meaning that it is made from oil. As a result it can off-gas noxious fumes as it wears. Every mattress contains foam. So what is that smell in memory foam? It is the off-gassing of toxic chemicals and is noticeably strong for weeks to months. This has been known to cause headaches and other severe health reactions in people who sleep on them.
Mattress materials differ depending on not just the type of mattress but on the placement in the mattress. A modern mattress will consist of three layers of materials: the core or support layer, the comfort layer and the quilt layer. Each layer is made of different materials.