Health care workers in British Columbia face exposure risks from hazardous drugs via contaminated surfaces. This study evaluated the effectiveness of closed-system drug transfer devices (CSTDs) in reducing surface contamination and explored the change management experience of health care workers during CSTD implementation within the Fraser Health Authority. A before-and-after study design was used across four facilities, with surface wipe samples collected at three time points: one month before implementation (T0), one month after implementation (T1), and five months post-implementation (T2). A total of 156 samples were analyzed for 11 hazardous drugs. Results showed a statistically significant reduction in contamination from T0 to T1 and from T1 to T2 (p < 0.01). A staff survey also revealed positive feedback on the implementation process, though respondents recommended varied training formats and improved communication. These findings confirm the effectiveness of CSTDs and highlight important considerations for optimizing future health and safety initiatives through responsive change management strategies.