Before you ask if a memory foam topper is good for your child, is his mattress alright? Because, frankly, that is the most important thing. Way too many people try to use memory foam pads as a cheap fix for a sagging mattress, or a mattress that is too soft. Unfortunately, this just does not work. For a memory foam mattress pad to work well, it needs to be placed on top of a firm mattress.
Now, let’s move on to the safety aspects. Memory foam is NOT safe for babies. A baby may turn over to lie face down on a foam pad and suffocate because she does not have the strength to turn back up. In fact, this is true of any mattress that is made of a dense material. Such materials last a long time, but they are impermeable to air. If you stuff someone’s face in them, they act like a plastic bag and will suffocate that person.
On top of that, babies have sensitive lungs. Memory foam usually releases a little bit of Volatile Organic Compounds (VOCs), especially when just unwrapped as well as when they get old. Furthermore, because they are inflammable, most bedding manufacturers inundate them with flame retardant chemicals, and this further aggravates any sensitivity in the lungs. This problem holds true with anyone with a sensitive respiratory system, e.g. even adults with asthma or some other lung disease may be affected. Basically, babies and those with a lung problem should stick to untreated organic bedding.
The inflammability of memory foam brings up an important point. If your child likes to play with fire, you should avoid getting a foam pad for him. Even if the memory foam bed topper is treated to be flame resistant, it is better not to take chances. After all, the flame retardant treatment only lasts as long as the chemicals do not evaporate off the topper. After many years, the treatment will weaken.
In short, from the safety point of view, babies, children with respiratory trouble, and kids who like to play with fire should not be given memory foam pads. From the practical point of view, a memory foam mattress topper works best on a firm mattress in good condition.