To study interaction loads between ice and sloping structures, numerical models are required that can predict failure of the ice based on physical ice properties, deformations and structural shape and size. An important component of these models consists of the failure criteria that are employed, as failure limits the loading of the ice on the structure. Failure in interaction with a sloping structure can occur in multi-directional tension, compression, bending, splitting or a combination of these, making it important to capture and combine all failure conditions in a single model. In this paper, these failure criteria are derived for a lattice model, linked to field measurements and failure envelopes are presented. For the first time, a complete set of failure criteria that is required to simulate ice-sloping-structure interaction scenarios, is derived in this paper. It is shown that the criteria have minimal dependence on cell-size and -orientation and are applicable for multi-directional loading conditions.