The reliance of minimally processed chilled foods on low temperature for distribution with optimized controlled/modified atmospheric packaging to maintain safety and quality poses new challenges to food microbiologists. Effects of controlled/modified atmospheric packaging conditions on microbial growth are briefly discussed. Microbial growth models are systematically examined with emphasis on the temperature dependence models—the Arrhenius model and the square root model. Their applicability for making predictions of both shelf life and safety under nonisothermal conditions is assessed. The use of time-temperature integrators for shelf-life prediction and safety assurance is also addressed.