Therma Premium shutters are made from non toxic, fully recyclable natural solid Polymer foam which looks and feel like wood. Environmentally friendly product which uses no old growth forest timber . It is naturally flame retardant, can be safely used in hospitals and schools, and very safe for domestic application. Water resistant, ideal product for all wet areas inside in bathrooms and outside for patios and balconies. High Thermal "R" values, the thermal insulating properties are 3 times greater than timber and up to 1500 times greater than aluminum.