A gaseous trace contaminant load model is presented for the Space Station Freedom Man Tended Capability (MTC) configuration at assembly flight MB-6. The model is based on offgassing data gathered in Spacelab missions SL-1, SL-3, SL-D1, SL-IML1, and human metabolic data documented in the NASA Bioastronautics Data Book. These data were extrapolated to create a list of contaminant generation rates for Space Station Freedom using materials data, mass properties data, and operations for the MTC configuration. Results of an evaluation of the gaseous contaminant load model against removal device performance are also presented. The evaluation was performed using a computer model to predict toxicological acceptability of the spacecraft cabin atmosphere at flight MB-6.