Hi JStevens,
What a great question! I do have many opinions on this and some of my thoughts and research on this is here
www.themattressunderground.com/mattresse...al-vs-synthetic.html
In spite of the fact that so many of the arguments about this controversy are portrayed as "black and white" I see it more along a spectrum and I personally like to be on the natural side and/or bio-friendly side of the spectrum even if I don't go all the way there. There is also a great deal of misinformation in this area and a misuse of words like "natural" and "organic" and many others.
For example ... wool or cotton or other natural fibers are widely regarded as natural and yet they can be treated with chemicals to make them "softer" or remove their natural oils or make them more fire retardant etc. Many of these treatments may not disclosed by the original suppliers. Bamboo is a natural ingredient and yet the methods used to make bamboo useful as a fiber for blending in a fabric (usually cotton) are certainly not natural and involve some rather potent chemicals ... yet they are marketed as "natural". There is also a current trend with polyfoams and memory foams to replace the oil based polyols used in their manufacture with plant based polyols ... usually made from soy or other plant oils ... and then they are advertised as being "natural" foams when they only contain a small percentage of these alternatives and the polyol after processing is no longer "natural". In the case of soy in particular ... much of the soy being used comes from the rainforest and the growing methods used are destructive so it is not at all "bio-friendly. Many materials that are "natural" in one part of their production or may start off with raw materials that are natural may involve "less natural" or even toxic processes or chemicals along the way from raw material to finished product. The term "organic" is also completely misused.
In terms of foams ... one of the reasons I prefer latex is that even in the synthetic SBR version (the latex raw material is either synthetic latex called SBR or natural latex called NR which comes from a rubber tree), I believe it has far less potential for harm than either polyfoam or memory foam regardless of the polyols used. Talalay latex usually comes in a blended version (a mixture of SBR and NR) or in a natural version (no SBR). The blended version is less expensive and has very similar qualities to NR which is why it is more popular. Dunlop latex has a wide variety of different "blends" but most of the higher quality Dunlop is mainly or all NR. This is because Dunlop uses a less complex and expensive production technique so tends to cost less thanTalalay even in the NR versions. I would personally avoid 100% SBR latex as I believe it is inferior in quality to a blend or NR latex but I like the blended Talalay. Latex either in SBR or NR versions is also more biodegradeable than other foams
While most of the memory foam or polyfoam that I would even consider has been tested by an organization such as CertiPur (or others) for VOC's (offgassing), I still believe that there may be some potential for "harm" as the foam breaks down into fine particles which can be inhaled as the chemicals in the foam itself may be toxic if absorbed.
While innersprings are certainly not toxic ... they also don't break down or biodegrade easily and even here there are some who believe that the metal can lead to biomagnetic disturbances.
Fabrics fall along a wide spectrum of "degrees of natural" but at least here there is often more certainty that when you buy something from a source that is genuinely concerned with natural and organic materials ... that they really will be.
All in all this is a controversy that is cloudy at best and each of us needs to decide the "tradeoffs" we will make as we move along the spectrum towards one end or another. Personally I tend towards natural ingredients but not to such an extreme that it becomes the primary basis of the decisions I make. All other things being equal or close to equal ... I will choose natural ... but I will also do my homework to find out where in the spectrum the materials that are being promoted as "natural" really are. There is also much more information about safe, natural, green, and organic materials in
post #2 here and the information it links to.
My own mattress contains both NR and blended Talalay latex along with a blended fabric ticking but on a personal level I would not have considered polyfoam or memory foam (even though there are some layering schemes that use memory foam in combination with latex that I quite like) as they are on the "other side" of the spectrum from where I prefer to be ... but this is personal opinion and "bias" only.
Phoenix