Hi Bhairavi,
Whenever you buy a mattress / topper combination (or a futon/topper) you are adding a level of uncertainty to your purchase because choosing the most suitable topper for a specific mattress or futon can be almost as difficult as buying a mattress when you can’t test the specific combination in person. The topper that works best for you will depend on the specifics of the futon, your body type, your sleeping positions, and your own preferences. While it can be a good option “in theory” … in practice it would depend on how well the combination works for your specific needs and preferences in terms of PPP (Posture and alignment, Pressure relief, and Personal preferences) and choosing the best topper for you may take some trial and error.
You may also want to assess some of your basic assumptions about what materials you consider to be “safe” and which aren’t so you aren’t being unduly influenced by some of the misleading information that is common around the web. I’m not sure if you are more sensitive to some chemicals than most people due to a medical condition such as MCS (Multiple Chemical Sensitivities) and need to avoid polyfoam in all your furniture or other materials in your home that most people would be fine with or whether it’s just a matter that you prefer more natural or organic materials as a personal preference. There is much more information about organic, natural, and “safe” materials in post #2 here and the links it includes that may help you sort out some of the complex and confusing and often contradictory information that can help you answer the question of “how safe is safe enough for me?” if it’s more a matter of your concern about the safety of some materials rather than how natural or organic they may be. There is no definitive answer to this question except based on your own preferences and circumstances. There are many synthetic or less natural materials that are just as “safe” as natural or organic materials and have been tested for VOC’s using the same testing methods as natural or organic materials.
You can read more about so called “soy based” foams or other “plant based” foams in post #2 here. They replace a small percentage of the polyols that are made from petrochemicals with a chemical polyol that is derived from a plant oil. They are basically just polyfoam and in terms of quality can be compared directly with other types of polyfoam based on their density.
I haven’t tried this in person but many have and for some it will work well and for others it won’t depending on the specifics of the futon’s materials and construction and the topper they choose in terms of the type of latex and the thickness and firmness of the topper. Natural fibers would generally be be a firmer and less resilient and responsive support system than either foam or innerspring support systems … especially as they compress over time … and wool will generally be more resilient than cotton and more costly. You may need to use some trial and error so that the topper you choose is a good match for your body type and sleeping positions with the futon you choose. It would need to be “just enough” in terms of thickness and firmness that it would isolate you from the firmness of the futon in your most pressure prone sleeping position. Different futons would be firmer or softer depending on their construction and materials so each futon design may need a different topper. Either way it will have a very different feel from more resilient support systems. The topper guidelines in post #8 here may help you use your sleeping experience on a futon by itself as a guideline for choosing a topper. The “best” option would be to test the specific combination you are considering in person.
It would be less “risky” to either choose a sleeping system that you can test in person and doesn’t need additional layers or components to make it “right” or to use a design for a mattress or sleeping system that has good options to make changes or replace layers (or a topper) after a purchase if you don’t have the chance to test it first and your choice turns out to be less suitable than you hoped.
If you choose the right combination it can work well … but the “trick” is to choose the right topper for the mattress/futon you are using and that is the best match for your unique needs and preferences.
Phoenix