Recent research has shown that the reported participation of employees in voluntary safety activities is related to the prevention of accidents and injuries. Encouraging such participation, then, is beneficial to organizations. A key question, therefore, is why employees should choose to report that they engage in such activities: what is their motivation given such activities are not compulsory? We used social exchange theory (SET) and organizational support theory (OST) to develop a model linking perceived organizational support to reports of safety participation. SET postulates that the benefits given (by an organization) are reciprocated with potential benefits to the giver as a result. OST emphasizes that feeling obliged is a key part of why people reciprocate the perceived support they get from their organization. Voluntary safety activities have the potential to benefit an organization, so for the first time, we test whether there is a link between perceived organizational support and the reported participation of employees in such activities, and whether the relationship is mediated by felt obligation. We also test whether another key SET motivation to reciprocate, the anticipated reward, is involved in mediating the relationship. A structural equation model with a sample of 536 workers from a Belgian public company, involved in the production and distribution of safe drinking water and in waste water treatment, supported the hypotheses of the authors. The model showed that felt obligation mediated the relationship between perceived organizational support and safety participation reports, and that the anticipatory reward, in the form of perceptions that management was committed to safety, also mediated the relationship between perceived organizational support and safety participation reports. These processes were shown to be separable from employee job engagement and employee perspectives on whether or not voluntary safety activities were part of their job. The findings add to the understanding of why employees choose reported participation in voluntary safety behaviors and also, add to the literature on OST by demonstrating for the first time the involvement of felt obligation and perceived management commitment to safety as mediators between outcomes and perceived organizational support.