I would like to know what raw material is used to produce synthetic latex. Can’t seem to find a discussion of this. And is there a “standard” composition or does it vary across manufacturers?
Thanks for your very informative articles & forum.
Hi Hoppy,
Welcome to the Mattress Forum! 
That’s a good question, but a very complex one.
Styrene Butadiene (SBR) is basically synthetic latex. You can read the Wikipedia description here, which details the creation of SBR from the monomers Styrene and Butadiene into the fully-reacted co-polymer Styrene-Butadiene. It’s like salt which is Sodium and Chloride which is different from either Sodium or Chlorine (which can be harmful by itself). It’s polymerized through either an emulsion or a solution process.
This paper gets into quite a bit more detail about the SBR process.
There is more information about the monomers Styrene here and Butadiene here.
Synthetic rubber in general is discussed here.
Both synthetic latex and natural latex are equally “rubber” or “latex” except natural latex is primarily isoprene rubber that comes from a tree (which can also be synthesized) and synthetic latex in the case of latex mattresses is made from Styrene Butadiene rubber (or SBR). Both natural and synthetic rubber are stable and inert materials when they are cured. This is similar to tires which also uses various blends of synthetic and natural rubber depending on the specific qualities that the tire manufacturer is looking for. Both natural and synthetic rubber used in mattresses … unlike tires … is foamed rubber which means that there are several other compounds that are needed in addition to the rubber to make the foamed latex core. These include curing agents, gelling agents, antioxidants, mold release agents, and other compounds that are used to make both natural and synthetic foamed rubber. These also become inert when the latex is cured or in some cases are washed out when the latex is washed after manufacturing.
In terms of safety … all the latex you are likely to encounter (whether it’s Dunlop or Talalay and made with natural rubber, synthetic rubber, or a blend of both) will have been tested for harmful substances or VOCs by either Oeko-Tex or Eco-Institute and certified as being “safe” so safety wouldn’t be an issue for most people regarding any type or blend of latex (see post #2 here for more about certifications)
If you’re concerned, IMO … the best way to determine the “safety” of a material is with the testing certification it has (otherwise you would need a degree in material science or chemical engineering to answer these types of questions from a more technical level) but no matter how safe a material may be each person needs to answer the question of “how safe is safe enough for me?” or decide on their comfort level with a certain material on an individual basis.
As an example …
You can see a material safety data sheet for styrene butadiene co-polymer here.
You can see the material safety data sheet for polyisoprene (the main ingredient in natural rubber) here.
I know this may be more information than you desire, and much of it gets into the weeds, but I wanted to organize some of the SBR information that was spread throughout the site into one location for you.
Phoenix