There is a lot of memory foam coming from China these days. I do not believe they make quality memory foam yet. The quality of memory foam is based on many factors such as: the manufacturer, proprietary formulas and processes, density values, firmness determinations, and thickness. High density values (4 - 7 PCF) is what makes memory foam unique but that is not all you need to consider. Remember the IFD value. It is easy to make a heavy mattress (4 - 7 PCF) that is firm or stiff, but quality memory foam is dense yet still soft and elastic.
Some unscrupulous manufacturers are aware that consumers are looking for high PCF values and so incorporate additives into their foam formulas that increase the density of their foam but not while maintaining a low IFD value. If they provide you a PCF value but are not able to give you the IFD value I would look elsewhere.
The odor of memory foam is also an issue with people. New memory foam does have its own characteristic odor but this does diminish over time. Despite what some may have you believe, the odor of memory foam is not a big issue. There is always a small fraction of the population that is allergic to something. In fact a small fraction of the population is allergic to penicillin. Allergic reactions to memory foam are rare and not the norm. However, if you are someone who is prone to allergies then I would certainly stay away from made in China memory foam, at least until their quality improves. The odor of memory foam is mostly dependant on proprietary formulas and processes and this is something that is only learned with time and experience. Most of the older more experienced memory foam manufacturers are in Europe and the US.
This does not mean that there is no quality memory foam coming from China at all. There may well be. Just remember to look for memory foam with a density in the range of 4 - 7 PCF and an IFD in the range of 12 -16. If you come across some memory foam with a density of 4 - 7 PCF but with an IFD value above 20, chances are it will not be as elastic and temperature sensitive like true quality memory foam. If you are thinking about a memory foam brand made in China be sure to get both the density and IFD values and at least confirm the density value as described in this website.
I just bought a memory foam topper from Therapedic, a US company. The tag on the topper says it was made in China. It has a terrible odor. I have read that this odor is the outgassing of toluene, which is carcinogenic. So, I feel like while the mattress smells, it’s still dangerous. If the mattress doesn’t smell anymore, will it still outgas toxic materials? Thanks.
Yikes, yes toluene is carcinogenic. If it were me I would not keep it, I would try to return it.