Foam Mattress Guide

History

• Foam rubber mattresses have been in use since the 1950s. They provide an alternative to spring or coil type mattresses, which can lose their shape and became lumpy and uncomfortable. There are two basic types of foam that mattresses are made of: latex foam rubber and memory foam. Latex foam rubber can be made of natural or synthetic materials.

  Researchers in the 1970s at the National Aeronautics and Space Administration (NASA) were searching for a substance that could cushion astronauts on take off. The material they developed became known as visco/memory elastic foam, which was also the perfect foam to cushion a person while sleeping. Visco, soon to be known as memory foam, conforms to a persons shape, including pressure points such as hips and shoulders, but bounce back as soon as a person moved. In the 1990s, memory foam mattresses began to be manufactured in the United States. Visco foam mattresses are usually more expensive than latex foam.

Types of Foam

• Both latex foam and visco foam can be used on firm surfaces such as platform beds without the need for box springs. The difference between the two is that latex rubber has a higher resiliency than visco foam and will feel springier and bouncier. Visco foam feels more solid where it will not push back up when you press down on it--it raises back up more slowly. Some mattresses companies are using a combination of these two types of foam. The other difference between the two types of foam is that some people are allergic to latex, in any form, and break out in a rash.

  In some parts of the world, both types of foam had been treated with the toxic fire-retardant chemical plybrominated diphenyl ethers (PBDEs). The manufacture of foam bedding with this toxic substance has been partially outlawed in the United States but there are some loopholes and some furniture is still entering the country treated with it. Furthermore, your old mattresses may have been treated with PBDEs. In addition, make sure the foam mattress is not made of polyurethane, which has also been shown to be toxic.

Comparison Ratings

• Foam mattresses are rated in different categories that indicate how well the mattress rebounds quickly into its normal shape. These ratings also indicate a foam mattresses quality and durability. Look for the following ratings when buying a foam mattress: weight, indentation load deflection, resilience tensile.

Density

• Look for the weight or density in pounds per square inch; the higher the density the more elastic the foam will be. A good foam mattress will have a 4 or 5 pound density, according to the Memory Foam Mattress Organization.

Load, Resilience and Tensile Strength

• The Indentation Load Deflection or ILD rating tells how hard or soft the foam is. A high ILD indicates a firmer mattress.

  Resilience measures the amount of spring the mattress has. This rating is tested by dropping a steel ball from 36 inches above the mattress and seeing how deep the ball bounces. A higher resilience rating indicates a more durable mattress.

  The tensile test tells how durable the foam mattress is. Manufacturers test this by stretching the mattress to see how far it can stretch before it ruptures. A higher tensile score means a more durable mattress.

Odor

• Most foam mattresses, even those made in the United States, may have a strong smell that may last a couple of weeks but will soon go away. For some people this smell is very offensive. If it bothers you, open up the mattress and store it in another room until the smell fades away. Wash your sheets every day for the first week of using the mattress to reduce the smell as well.