Hi Olichar,
All the latex you are likely to encounter (either Dunlop or Talalay or made with natural or synthetic rubber or a blend of both) will have been tested to similar criteria (either Oeko-Tex or Eco-Institut) for harmful substances and VOC’s so I would consider any latex to be safe (see post #2 here). Latex hybrids such as the Sealy Optimum also contain other materials such as the polyfoam used in the base layer which may have more VOC’s than the latex. If polyfoam is CertiPur certified then it would also have been tested for harmful substances and VOC’s and while the testing protocol isn’t as stringent as Oeko-Tex or Eco-Institut, for most people it would also be “safe enough”. There are no “all memory foam” mattresses since memory foam is only used in comfort and transition layers.
Outside of knowing the specific results of any testing that has been done on a material there is no way to quantify the specific amount of VOC’s that may be coming from any material but in very general terms … out of the three main types of foam material … for those that are more sensitive or have health conditions such as MCS (multiple chemical sensitivities) the highest odds that they may be sensitive to a foam material would be with memory foam, followed by polyfoam, and the lowest odds would be with latex. There is more information in post #2 here and the posts it links to that may be helpful for those that are trying to research the confusing and complex issues that can help them answer “how safe is safe enough for me?”.
The tutorial post includes this link to a list of the members here that sell mattresses online and many of these sell all latex and/or latex hybrid mattresses that use different types and blends of latex that have a wide range of designs, options, prices, and return or exchange policies that would be well worth considering and would be better quality/value than the Sealy Optimum…
If you let me know your city or zip code I’d also be happy to let you know if there are any other options or possibilities i’m aware of in your area.
Phoenix