The main benefit of cooperative vehicular communication networks is the increased traffic safety that safety applications could introduce. Although the technological aspects have been extensively researched, the feasibility regions in which communication could support safety applications are yet not clear. This is, primarily, due to the lack of clearly defined application requirements. Moreover, reduction of false positives and false negatives are either not considered at all or only partially. In the current paper we investigate under which conditions vehicular communication can support safety applications. For this, we identified the requirements of safety applications, on the example of Forward Collision Warning, first from application perspective and pursuing zero false positive and zero false negative constraint. Afterwards, we quantify what is the maximum vehicle density for which application requirements can be supported under realistic communication conditions, as well as how much the idealistic application requirements have to be relaxed in order to achieve a balance between scalability and zero false rates.