Hi debating,
Other than the “so called” natural memory foam (which I don’t believe is natural) … as far as I’m aware they use 100% natural latex in their base layers (but of course they can confirm this).
While I don’t think that for most people they would be the best “value” choice … they do use good quality materials and there are no obvious weak links in their mattresses that would compromise the durability or useful life of their mattresses.
A warranty is important to guard against manufacturing defects in the materials or components inside a mattress that can happen on rare occasions … but I would also keep in mind that mattress warranties only cover manufacturing defects and they don’t cover the gradual (or more rapid in the case of lower quality comfort layers) loss of comfort and support that comes from foam softening that is the main reason that most people will need to replace their mattress. In other words warranties have little to do with the durability or useful life of a mattress or how long it may be until you will need to buy a new one. If there is an actual defect in the materials it will usually show up early in the life of the mattress but knowing the quality and durability of the materials inside a mattress is always a much more reliable way to assess the durability and useful life of a mattress than the length of a warranty. There is more about mattress warranties in post #174 here.
There is no way to quantify how long any mattress will last for a specific person or predict exactly when you will decide to replace it because it is no longer suitable or comfortable for you (because this is the only real measure of durability or the useful life of a mattress that really matters) because there are too many unknowns and variables involved that are unique to each person … if a mattress is well inside a suitable comfort/support range and isn’t close to the edge of being too soft when it is new (see post #2 here) and you have confirmed that it meets the minimum quality/durability specs that are suggested in the guidelines here then it would be reasonable to expect a useful lifetime in the range of 7 - 10 years and with higher quality and more durable materials like latex or higher density memory foam or polyfoam (in the comfort layers especially) it would likely be in the higher end of the range or even longer and the chances that you would have additional “bonus time” would be higher as well.
All the major brands (such as Sealy/Stearns & Foster, Simmons, and Serta) tend to use lower quality materials in their mattresses than most of their smaller competitors that will tend to soften or break down prematurely relative to the price you pay and I would avoid any mattress where you aren’t able to find out the type and quality/durability of the materials inside it (see this article) and confirm that they meet the quality/durability guidelines here which would exclude almost all of the major brand mattresses and the major chain stores like Sleep Country that specialize in them (see the guidelines here along with post #3 here and post #12 here and post #404 here).
All foam materials have “some” VOC’s so it’s not possible for any manufacturer to claim that a mattress that contains any type of foam material (including polyfoam, memory foam, or latex foam) contains no VOC’s at all. The goal is to make sure that any materials in a mattress don’t contain harmful substances or VOC’s in amounts that would be harmful. The only reliable way to assess the “safety” of a material in more general terms is based on any laboratory testing and certifications they have for harmful substances and VOC’s (see post #2 here for more information about some of the reliable “safety” certifications) and if the materials in a mattress have a reliable “safety” certification then for most people they would be “safe enough”.
The amount of any particular substances would be more important than whether they are present at all. There are also many sources for formaldehyde inside the home besides just the materials in a mattress and there are also natural sources for it as well so there is even some formaldehyde in background amounts in ambient outdoor air (see post #6 here).
Phoenix