Can Thermafleece burn?
When exposed to fire, wool self extinguishes and naturally melts away from the flame source. Thermafleece is also treated with a natural fire retardant, Borax that improves its fire resistance and complies with British Standard BS 5803-4 with regard to flammability and resistance to smouldering. Thermafleece has a higher fire resistance than both cellulose and cellular plastic insulation.