A new photochemical method for a permanent flame retardant finishing of textiles made of cotton (CO),
polyamide (PA) and polyester (PET) is described. Using a mercury vapour UV lamp vinyl phosphonic acid
(VPA) can be fixed durable to different fabrics made of CO, PA and PET in the presence of a cross-linking
agent and a photo-initiator. After a home laundering cycle up to 50 wt% of the reaction mixture is
retained on the fabrics and the absolute phosphorus content was found to be more than 2.0% in all
investigated cases. The photochemically modified textiles showed high levels of flame retardant
performance and passed a vertical flammability test for protective clothing.