I bought a topper from a company associated with physio.----- The mattress came and it too had a very high smell of chemicals, so much so it had to go into the spare room with the windows open for about a week. After that it was fine.
It is now 2 years since we got the topper which cost 110.00pound(GBP). I feel though it now needs changing, it has a lump(best way I can describe it) in the middle even though we moved it upside down and inside upside everyway. I feel I was sold a real fake. This was not off ebay but read everything on the description before you decide to bid or buy.,.
Try and buy the best u can afford but it is well worth saving up and getting the more expensive and GAURANTEED..