Hi MFC Memory Foam Comfort
Unless you have a mattress with a zip cover that gives you access to the individual layers and there are any identifying stickers or markings on the layers that would identify the materials (which may or may not be the case) you would be dependent on trusting the reputation, integrity, and knowledge of the manufacturer or retailer you purchased it from. The same would be true about any type of mattress and the materials inside it because if a manufacturer or retailer really wanted to deceive their customers about what is inside their mattresses they certainly could since most consumers wouldn’t have the knowledge or experience to be able to identify the specifics of the materials inside any mattress they purchase.
I would certainly trust the members here and I recommend them “as a group” although there are also many other manufacturers or retailers that are mentioned in the various forum lists that I also think highly of and would trust as well.
Post #4 here also has a list of the better online sources I’m aware of for individual components and materials that include different types and blends of latex as well and there is also a list for manufacturers and retailers that ship across Canada (including yourself) in post #21 here.
Phoenix