Our 100 IFR% polyester velvets are flame retardant for the life of the curtains. They should never require additional FR retreatment. Depending on their environment, we suggest periodic cleaning. We recommend annual field testing.    Light vacuuming with a soft brush keeps 100% IFR polyester curtains fresh and removes airborne pollutants, such as dust and allergens. Dry clean these curtains as often as needed.   Our 100% FR cotton velvets will require dry cleaning for extended exposure to high or low humidity, or unusual dust build up. These conditions can degrade FR performance. Cotton velvets require new FR treatment after dry cleaning and we recommend annual field testing.   Light vacuuming with a soft brush and keeping the area clean and dust-free will reduce the need for dry cleaning.