I wanted to share some information with you from our blog about this topic.
The Healthy Children Project recommends ” buying clothing, bedding and furniture made of natural fibers, such as cotton and wool, which do not melt near heat and as such do not need to contain flame-retardants.” The Environmental Working Group says, “To avoid any chemicals in sleepwear and reduce the risk of igniting sleepwear, we suggest you choose natural fibers that are inherently fire resistant and snug-fitting.”
Most children’s sleepwear is made of polyester (fleece), nylon acetate, and rayon. These fabrics begin their lives as a vat of chemicals, including petroleum. They have a prolonged landfill life, create more dependence on oil and take 40% more energy to produce than cotton. They are not breathable and block out air sometimes causing the body to overheat. These synthetics can also emit toxic gasses and are allergenic, causing respiratory disease in some cases. Polyester is plastic and will melt when heated. Synthetics must also contain flame retardants.
Hope this helps:)