This has actually been a discussion for many years. Some memory foam mattresses have been found to contain VOC’s which can be very harmful to humans especially to babies. This is why those mattresses supposedly smell like gasoline.
VOC’s can cause cancer….it’s the same component that’s been found in paint and other substances that have already been banned from use.
If you think you’ve bought a mattress with high content of VOC and it’s impossible to return this and get your money back, then you can opt to not use it right away. Let it off-gas first as what some people have been doing. Take it out of the package and put it in the garage or air it out in the attic. Let it stay there for at least two weeks to get rid of the smell (which can really hurt sensitive people).
Additionally, here are some more information about toxic substances that may be harmful to your family.