As for any novel nanomaterial, the applications development and industrial adoption of graphene-based materials will be subject to confirmation of their safety profile and risk assessment. The analysis performed here maps the current knowledge on the safety of graphene materials as extracted by a literature mapping exercise of the studies investigating the material in preclinical animal models. We attempt to identify gaps for future studies and elucidate the critically important structure-function correlations between reported biological effects and graphene material physicochemical characteristics.