One of the safety issues related to ITER concerns the potential impact of Tritium that could be released to the environment in a postulated accident. As the final site located at the vicinity of Cadarache nuclear facilities in France is known, some calculations have been made to assess the effect of the nominal release of 1 g of tritium for ITER site specific characteristics. Sensitivity studies have been performed according to these characteristics, but also to assumptions related on the way the tritium could be accidentally released (chemical form, height of the releases...). The results being used for demonstrating the low impact of tritium accident releases, care has been considered on the selection of the most penalizing assumptions in terms of results. The results have shown that, whatever are the assumptions, the consequences of 1 g of tritium that could be accidentally released into the environment is extremely low, in the domain of low doses. In spite of this very low impact, many safety provisions are undertaken with regards to defence in depth principles in order to further reduce both the likelihood of an accident involving tritium and its consequences.