There is frequent confusion about the type of foam used in mattresses produced for use in a nursing context. People are often uncertain how they should interpret the information provided by manufacturers. Every manufacturer uses its own terminology, making it even more difficult to understand things properly.

In general, the type of foam used is polyurethane foam (in this sector of the market, we also speak of “cold foam”). This is available in both hard and soft versions. The actual hardness or softness is determined during production of the foam by the use of additives such as water.

It is important to note that this has nothing to do with the density or specific gravity of the foam. That is expressed in kilograms per cubic meter (kg/m³), i.e. the weight of a block of foam measuring 1 x 1 x 1 metres.

The density of the foam is to a large extent responsible for its quality. In other words, a block of foam measuring 1 x 1 x 1 metres with a density of 43 kg/m3 has less “mass” (i.e. amount of foam) than one with the same dimensions but a density of 55 kg/m3.

To put it very simply: the lower the density, the lower the quality of the foam and the shorter its durability, especially in intensive use at a hospital or nursing home.

Nowadays, “slow” (visco-elastic) foam is very popular.

Every producer has its specific types of “slow” foam but they all basically amount to the same kind of thing. In actual fact, this type of foam has long been used in the packaging industry, so it is not really all that new. The original term for “slow” foam is “Shock Absorbing Foam” (SAF).

Slow foam is also made of polyurethane but special additives give it its “slowness”. Unlike other types of foam, which immediately spring back to their original form when you press and release them, slow foam – as the name implies – only does so gradually.

Slow foam also has the unique property of conforming to the shape of your body due to your weight and body temperature. This means that pressure is distributed evenly, thus protecting sensitive parts of the body that may be at risk of developing bedsores.


It is important for foam to be produced in an environmentally friendly manner, without using CFCs. Polyurethane foam is basically an environmentally friendly product and can be recycled both mechanically and chemically.

Safety aspects are playing an increasingly important role. Most manufacturers are capable of producing a polyurethane foam that complies with the CRIB5 standard for fire retardancy but few can produce a slow foam that meets that standard.