In this work, polymer films of low density polyethylene and ethylene-vinyl acetate copolymers containing two types of antifog additives (nonionic surfactants) were exposed to two simulated horticultural greenhouse environments, reproducing hot and cold climate conditions. The evolution of the antifog effect was visually observed and that of the additive concentration measured using Fourier transform infrared spectroscopy (FTIR). All the films studied showed good antifog properties, but in all cases, the duration of the antifog effect was longer in the hot-climate test. From the FTIR, we can conclude that the additives Studied showed a low migration rate and, therefore, when the antifog effect is lost, important quantities of the additive remain in the bulk. (C) 2008 Wiley Periodicals, Inc. J Appl Polym Sci 111: 2299-2307, 2009