Safety motivation is, nowadays, acknowledged as a key determinant of safety performance. The relationship between motivation, work injuries and accidents has been confirmed by numerous studies that found that safety behavior is associated with fewer injuries and accidents and that some safety behavior, voluntary safety behavior (such as safety participation), is largely induced by motivation to work safely. Safety motivation can be considered as a multi-dimensional construct, in which it is possible to distinguish between controlled safety motivation and autonomous safety motivation on the basis of the degree of internalization of safety motivation at the individual level. The aim of this study was to shed some light on the antecedents of safety motivation and, in particular, on the role of safety values (i.e. individual perception of the priority given to safety at work) as a mediator between perceived quality of Personal protective equipment (PPE) and both dimensions of safety motivation: autonomous and controlled. The sample consisted of 426 employees who worked in three process industries. The data was collected by an anonymous questionnaire with validated measures. A statistical mediation model was adopted to analyze the data. The results show that general safety motivation is affected by perceived equipment quality directly and indirectly (via company safety value). Controlled safety motivation is not affected by perceived equipment quality (directly or indirectly). On the contrary, autonomous safety motivation is affected by perceived equipment quality directly and indirectly (via company safety value).The results are essential to define how PPE should be introduced not only to protect the workers but to increase their safety motivation too.