There is increasing evidence to suggest that leaders need to use a combination of leader behaviors to successfully improve safety, including both transformational and transactional styles, but there has been limited testing of this idea. We developed a leadership intervention, based on supervisor training in both transformational and active transactional behaviors, and implemented it with supervisors at a UK-based chemical processing company. The study found that the supervisory training intervention led to significant improvements in perceived employee safety climate, over an eight-week period, relative to the comparison group. Although we found no change in the frequency of leader behaviors, the intervention was effective in helping supervisors to apply active transactional leader behaviors in a safety-critical context. The results indicated that transformational leader behaviors were already at a high level and effectively linked to safety. Our findings suggest not only that employees may be receptive to safety-related active transactional behaviors within high-risk situations, but furthermore, leaders can be trained to adjust their behaviors to focus more on active transactional behaviors in safety-critical contexts.