The transport of gases such as water vapor and oxygen are a critical consideration for many packaging applications. Also, the migration of small quantities of volatile impurities in polymeric packaging materials is a health and environmental issue. The Center's capability to measure and correlate solubility, diffusivity and permeability has been quite useful in attacking various packaging problems. The ability to correlate and predict gas and vapor diffusion not only above the glass transition temperature, but also below the glass transition temperature has been particularly useful in the investigation of impurity migration from packaging.