History

• In 1966, scientists at NASA began experiments to develop an alternative to traditional cushions for use in air and space crafts. Scientist Charles Yost and his team developed what we now call memory foam. In 1991, Swedish company Fagerdala World Foams released their "Tempur-Pedic Mattress" to the general public for sale. In the early 1990s, other companies began producing their own mattresses based on memory foam technology. Since then, memory foam has also been used in sports equipment and hospital bedding.
  
  

Features

• Memory foam is made of mostly polyurethane in a dense, elastic form. Other chemicals in memory foam, like butadiene, chloride and dimethylformamide, are used to bind the polyurethane and prevent it from breaking down over time. Memory foam is denser and heavier than other types of foam and other kinds of mattresses. Memory foam is distinct because it responds to body temperature and pressure. The foam molds to the body shape instead of creating depressions only at pressure point areas.
  
  

Function

• The most common use for memory foam is in mattresses. Doctors recommend memory foam mattresses to people who have muscle, bone or joint disorders. Memory foam is also used in cushions for seats in commercial vehicles and air crafts. Hospitals use memory foam pads in hospital bedding to prevent bedsores or reduce pain caused by chronic disorders. Sport helmets and pads also use memory foam as padding.
  
  

Identification

• Memory foam is measured and identified by density. The density of the foam impacts its firmness. Density is measured in pounds per cubic foot. Other bedding materials have a density measurement of around 3 pounds per cubic foot, but memory foam can be as dense as 5 pounds per cubic foot. The indentation force deflection (IFD) rating is used to measure pounds of force necessary to make a 1-inch dent or impression in a memory foam mattress. A soft mattress has an IFD rating around 10 and a firm mattress has an IFD rating of up to 16.
  
  

Considerations

• Memory foam is made of a condensed material that does not always facilitate air flow; some people find memory foam mattresses too hot to sleep on because of the lack of circulated air. Memory foam mattresses are made of chemicals that might irritate people with a chemical sensitivity; the chemicals in memory foam also cause a smell that should dissipate over time.