The panel is made entirely of polyester hence it is inherently flame-retardant. The weight of the panels ranging from 2-3kg. The panel is composed of PET (Polypropylene Terephthalate) with NRC 0.6-0.7 which has the good sound-absorbent characterictics.It's 100% recyclable and there is low to almost undetectable formaldehyde contents.