What is memory foam made of?

Memory Foam is a chemically produced foam, not too dissimilar to other foams you may have around the house. The difference is that Memory Foam is viscoelastic, or reacts and softens when subjected to heat.

VASCO 60Memory foam comprises of a number of chemical compounds used in its manufacture. Each brand may use different suppliers from different countries. This means that Memory Foams won’t all share the same exact chemical compositions, each manufacturer will have their own recipe or formula. Each country also has its own chemical standards and accepted rulings of the use of them. A cheaper mattress from China may have a completely different ‘accepted’ set of chemical ingredients to one manufactured in the UK or USA. This ingredient list is kept a closely guarded secret.  The Fire Regulations set by each country differ so imported Memory Foams may not meet the requirements of the UK.

That said there is a set of some 61 ingredients that are likely to be found in Memory /Viscoelastic Foam.

Memory Foam is manufactured as a polyurethane foam using water, isocyanates (common examples toluene diisocyanate and methylene diphenyl diisocyanate) and polyols (common examples glycerine, petroleum, plant-based oil derivatives) which are usually sprayed onto each other on a conveyor belt and then combined with a reactant that acts as a catalyst to create an open cell structure.

This may all sound very complicated but we simplify it as follows:

  • Water and a number of chemicals are combined (isocyanates & polyols), with an agent (reactive)
  • This makes them then react a certain way aerating them (giving them the open cell structure) to create a foam.
  • These are either sprayed continuously onto a conveyor belt or then poured into moulds and allowed to dry.
  • Once dry you have the finished product of ‘Memory Foam’.

A small change in some of the chemicals then alters the density, hardness or response rate of the foam. The majority of foams are manufactured using a slabstock manufacture process, which is the process above of making large ‘slabs’ of Memory foam using the conveyor belt process rather than individual moulds which would be incredibly expensive.


The end result is a foam which reacts to heat, making it mould and conform to whatever shape and pressure that is placed upon it, usually a human! Memory foam is often described as a foam that allows you to sink slowly into it as it moulds to your body.  Interestingly people either love or hate this sensation, but fear not there are a variety of variations of these properties!  Hybrid Foams, for example, don’t need as much heat or mould as much. Latex, on the other hand, is vastly more responsive than memory Foam.