A kinetic model has been derived from the classical (Fick and Henry's) laws of the gas theory for predicting the oxygen permeability of a closed composite container, initially filled by pure nitrogen under a pressure slightly higher than the atmospheric pressure. Its two main parameters, namely the coefficients of oxygen solubility and diffusion, were determined beforehand by routine laboratory tests of oxygen permeation at 20, 30, and 45 • C. It appears clearly that oxygen molecules will quickly cross the composite wall to progressively modify the gas composition inside the container. Several solutions are proposed for trying to reduce the oxygen permeability.