I aired this out for 48 hours as the instructions said. As the 6th memory foam topper I've purchased I expected a smell. All 3 of my dogs started sneezing and having runny noses after I put it on my bed, under a mattress pad, sheets, blankets, etc. sleeping on it felt average compared to other memory foam toppers of similar size and price. After the third morning the dogs were at their worst, sneezing and with runny noses. This has not happened with any other toppers I've had. I took it off my bed, washed everything, and banished it to the basement to air out. I suppose I might be able to use it on a guest bed but I won't bother trying it again on mine. Too much effort to return or I might do that.