Employees’ engagement in safety is assumed to be a significant contributor to safety performance within the chemical industry. The current study tested this assumption by examining the role of prosocial safety behaviors (e.g., helping others) and proactive safety behaviors (e.g., seeking change) in predicting four safety performance outcomes: micro-accidents, property damage (accidents without injury), near-miss events, and lost-time injuries. Two-wave data collected from 511 employees located in 2 Italian chemical plants revealed that prosocial safety behaviors predicted micro-accidents and property damage, and proactive safety behaviors predicted near-miss events and lost-time injuries. These results suggest that benefits can be gained from distinguishing between prosocial and proactive safety behaviors when seeking to improve safety performance. Organizations may reduce the rate of minor injuries and property damage by increasing helping among employees. However, this approach will be less effective in reducing more serious accidents or increasing near-miss event reporting. More effective in these cases is creating environments in which employees feel able to raise their suggestions and concerns about safety.