Memory foam mattresses are platforms comprised of a mixture of polyurethane and other chemicals to grant it the combination of pliancy and inelasticity for which it is known. There are two density variations of memory foam; high density memory foam is responsive to temperature, as it increases in malleability when warmed, while low density memory foam is responsive to pressure. The firmness of memory foam is calculated using a rating system known as Indentation Force Deflection (IFD), however, its accuracy has been controversial.
Some believe that it is more conclusive to measure the density of memory foam in order to determine the quality and comfort level of the mattress. This has also been contended because there are modulations between the performance and feel of low and high density memory foam mattresses, and it is thus asserted that an ideal memory foam mattress has a balance between density and IFD score. The logic behind this is that a denser memory foam mattress will be firmer and potentially less comfortable, but a less dense memory foam mattress can exhibit low resilience.
Memory foam mattresses have an open cell structure for their chemical composition. As a result, the tightness of the cellular structure determines the airflow throughout the material. For looser cellular structures, the memory foam mattress will be less odor retentive, will detain less heat, and will exhibit better recovery in shorter periods.
Thickness is also a determinant of the character of the memory foam mattress. Memory foam mattresses and toppers that are less than 2 inches thick will not provide any benefits from the material. Alternately, memory foam mattresses and toppers that are six or more inches thick will be too dense and yielding to be suitable to sleep on. Every degree of thickness within this range results in a different feel and ultimately, different resting experience with mattress or topper.
Given the chemical constitution of memory foam mattresses, they are combustible. In response, most manufactures have infused memory foam mattresses with high levels of polybromiated diphenyl ethers (PBDE), though it has been established that such levels of such chemicals can be hazardous. Subsequently, and particularly in the European Union, PBDE’s are no longer used in memory foams, which may indicate that they are currently more flammable.
Other hazards include the fact that its open cellular structure can result in dust and dander emissions, which can cause respiratory irritation. The degree to which this issue is liable to arise is proportionate to the density of the material. Airing can also reduce respiratory implications associated with memory foam mattresses. Moreover, it is advisable that these mattresses are not used for babies and small children, as the nature of the material may hinder movement and result in suffocation.
As more memory foam manufacturers enter the market, such mattresses become more affordable. Given they are highly desirous type of mattress, interest in the products has grown as their prices have reduced. This is due to the fact that they are touted as some of the most comfortable and ergonomic mattresses on the market in addition to the fact that they have therapeutic properties that can aid in pain relief and sleep regularity.