My earliest encounters with “memory foam” was some 15 years ago when my aunt brought a memory foam pillow from the USA to South Africa, where I was living at the time. I remember being amazed at this apparent new technology that I heard had been developed by NASA for use in space. No one else in the country had such a pillow of what I believed to be cutting edge technology that would magically conform to the shape of your face. How cool is that? I don’t sleep comfortably unless I use my “memory foam” pillow.
Roll forward to today and the marvel of this product has worn off somewhat. Maybe it has to do with the fact that I am further chronologically challenged, have a small child now, and am studying public health, but when I opened up the mattress-in-a-box “memory foam” mattress, I excitedly purchased last week, I was suddenly overwhelmed by extremely noxious fumes that emanated from the strange foam that popped out of the box. Thinking to myself that this cannot be healthy for a small child and pregnant wife, I began looking closer at what I previously thought to be a technological wonder was exposing us to so intimately.
“Memory foam” is polyurethane foam with additional chemicals to increase its density and viscosity and as such is often referred to as visco-elastic polyurethane. It has the ability to react to body heat in a way that it moulds itself to the body shape in a few minutes. It was developed over 40 years ago by NASA as safer aircraft cushions but after the early 90’s, began to have wider commercial applications such as pillows and mattresses, especially in the medical setting to reduce pressure sores, and nowadays even in football helmets.
So upon further research into what chemicals are actually in “memory foam”, I found that there are about 61 different chemicals that may be found in such products. Several are of major concern, such as formaldehyde, which was what the debacle regarding the FEMA trailers post Katrina was about, benzene, a known carcinogen, and a variety of flame-retardants. PBDE (Polybrominated diphenyl ether) was a very common flame retardant that was extensively used prior to its ban in 2004, when it was found to have cause numerous hormone disruption effects, particularly estrogen and thyroid. PBDE was replaced however by other similar chemicals, often guarded by mattress manufacturers as their flame retardant trade secret, but one such chemical is BDE-99 or PentaBDE (Pentabromodiphenyl ether), which I fear we are being exposed to on a daily basis.
There are no human studies on the absorption, distribution, metabolism and excretion of PentaBDE, but animal studies seem to suggest that it is readily absorbed from the gastro-intestinal tract and widely distributed to all human tissues, and furthermore can cross the placenta to an unborn fetus. Now one may argue that few if any of us chew on our mattresses when we sleep, but polyurethane dust which is known to emanate from these foams can settle everywhere and we all know how often one places ones hands in your mouth after touching everything. Metabolism pathways for PentaBDE appear to occur mainly in the liver as further metabolite products in the pathway are subsequently found in urine and bile. Excretion of PentaBDE appears to predominate in fecal and urine but animal studies also found significant quantities in breast milk.
Having understood what happens to the chemical in our bodies however does not give us an indication of what effects it may have on us in the short, medium or long term. Unfortunately there is scant evidence of toxic effects in humans that do not permit any conclusions to be made. Extensive animal studies demonstrate numerous hormone and enzyme receptor interactions, which may result in liver and thyroid damage as well as developmental problems such as hyperactivity and changes in motor behavior and other brain functions. Chronic exposure has not been adequately studied, but it has been hypothesized that it has the potential for causing cancer through its interaction with estrogen receptors.
The ubiquitous nature of these flame retardant chemicals surely warrants further evaluation and restriction if necessary. I for one am not comfortable on my mattress anymore, especially in light of the fact that we spend a third of our lives in bed.