Disclosed is the use of benzylidene malonates of formula (1) wherein R1 is methyl; ethyl; propyl; or n-butyl; if R1 is methyl, then R is tert. butyl; a radical of formula (1a) or a radical of formula (1b) wherein R2 and R3, independently from each other are hydrogen; or methyl; R4 is methyl; ethyl; or n-propyl; R5 and R6 independently from each other are hydrogen; or C1-C3alkyl; if R1 is ethyl; propyl; or n-butyl, then R is isopropyl; for the protection of human and animal hair and skin against UV radiation.