We used to sleep on bed mattresses made of more or less natural untreated stuff. But now, they tell you that you ain't cool, man, if you do not have a visco-elastic polyurethane foam (also called memory foam) mattress. They say this is the technological revolution in your bed, the Star Trek dream in your bedroom and the idea of the rigid mattresses is just a prejudice. It is being strongly advertised that the memory foam will remove your back, neck and articulation pains. Millions of people have got a better sleep and life quality, according to the sites selling these products, and, in their published surveys, about 90 % of the clients vote for these mattresses. More than in the elections held in a Communist country. But the sites do not mention that the foam is made from petroleum-based chemicals, starting from the proper foam to flame retardants and viscosity inducing agents. First: what does polyurethane mean? The term refers to any polymer made of organic units joined by urethane connections. By organic units you should understand hydrocarbons from the petroleum or derived chemicals. Theoretically, a fully reacted polyurethane polymer should be chemically inert. But any chemist will tell you that even fully reacted polyurethane can produce dust inducing mechanical irritation to the eyes and lungs. And, as there are no industrial processes 100 % complete, you should expect the polyurethane to expel its chemical load. Only the resin blends can expel isocyanates, which were proven to be skin and respiratory sensitizers, causing asthma. This is just a short list of toxins found in an analyzed type of memory foam: TDI (Toluene Di-Isocyanate), Polyol (Poly Ether Gycol), Silicone Surfactant, Tertiary Amine, Stannous Octoate, Flame Retardant, Pigments/Dyes. TDI is an aromatic hydrocarbon (it is really smelly) causing asthma. Tertiary amines have strong odors and are allergenic. No need to comment on the dyes... OK, I understand that the material can be used in various technologies, but how the heck you can make mattresses out of it? People spend around one third of their life sleeping. This way, you expose people repeatedly and continuously, for long periods, to low levels of chemicals. Sleeping on such a mattress or pillow exposes the person to tight contact to the chemical source, fact that increases several times the contamination degree. It is clear that the hydrocarbons evaporate and load the sleeping room. Most of the hydrocarbons are powerful carcinogenic chemicals and attack, with severe damages, the immune and nervous systems. Most autoimmune disorders (like arthritis, lupus, allergies asthma, and others) have been connected with or thought to be boosted by increased exposure to petroleum. Interestingly, in the US there are no exposure limits for carcinogenicity in the case of the polyurethans. Some researches detected very high levels of toxins, like arsenic and phosphor compounds, in the memory foams. Such actions forced producing companies to remove most toxic chemicals from the mattresses and pillows in many western countries, but the remaining stock can be sent to new virgin markets, unaware of the issue. Memory foam was originally developed by NASA, but the agency found it too expensive.