Hi brass,
Like you … I tend to take a more “balanced” approach to the issue of Chinese foams.
There are some things that you can know with certainty. One of these is that when it comes to polyfoam and memory foam that the polymer density of the foam (relative to other foams of the same type) is the most significant factor in its durability … regardless of the country of origin (see post #4 here about the factors that can affect the durability and useful life of a mattress). This is a matter of foam chemistry.
Another is that in terms of the relative “safety” of foam materials they can be tested for harmful substances and VOC’s so a certification such as CertiPur would be important.
Another is that foam additives can be used either as a filler to lower the cost of the foam or they can be added to a foam to change or improve its properties (such as gel materials or some types of filler to improve stiffness) so when there are fillers added to memory foam or polyfoam it’s difficult to know the effect it will have on durability.
Another is that regulations and oversight in China are not as stringent as regulations in North America (or at least the US and Canada) or in Europe.
Finally most foams that “fail” will tend to show obvious signs of failing in the first few of years of ownership so the experience of mattress manufacturers or retailers that use “poorly made” foams will also play a role in weeding out the worst foam manufacturers.
What can’t be known is the specific formulation of memory foam or polyfoam because these are proprietary to the manufacturer although in generic terms the chemistry of the same type of foam polymers is similar.
What you also won’t generally be able to find is specific testing for each of the thousands of foam variants that are used in mattresses compared to their specific competitors.
When you take all of this together it’s really a matter of the “risk” someone is willing to take or a matter of knowing how to tilt the odds of a good quality/durability choice in your favor. North American foam manufacturers are very competitive in terms of quality and while there are differences between them … mattress manufacturers will often change suppliers for similar quality/density foams without a significant change in durability. Chinese foam manufacturers are more of an unknown.
For me … if a Chinese foam manufacturer is well known and on the list of CertiPur certified foam manufacturers* (meaning they are one of the few willing to compete in terms of foam safety and durability testing with North American manufacturers) and the foam hasn’t been compressed in shipping for more than a few weeks to a month or so (if you can find this out) and if they don’t use fillers (which may not be possible to know for certain) then “in theory” Chinese foams would compare with North American foams of the same density on a relatively equal basis but the difficulty is that you usually won’t know for certain so there is always more uncertainty involved about whether the foam densities are an accurate reflection of their quality and durability.
ADMIN NOTE: *Removed 404 link|Archived Footprint: certipur.us/pages/for-industry/find-a-foam-supplier/
You can read more of my thoughts about Chinese foams in post #6 here.
Phoenix