This 100-percent Breathable mattress made from Bundle Fiber with memory helps regulate temperature by allowing air to pass through the entire mattress. It was designed with extra firm infant support and a comfortable plush side for your growing toddler. The cotton cover will easily zip off for a convenient washing experience every time. All materials used are hypoallergenic and safe for your little one to sleep soundly in. The Bundle Fiber with memory technology has all of the resilience of the highest grades of foam but there is no off-gassing (that chemical smell when you open a mattress with foam), VOC's or toxic emissions to ensure a safer night sleep. The Orion has no chemical flame retardants, phthalates, formaldehyde, or PVCs