Early Effects of the Serious Accidents Punishment Act on Occupational Health Outcomes in Korea: A Nationwide Difference‐in‐Differences Study (2017–2023)

BACKGROUND: Work-related injury and occupational disease remain major public health challenges worldwide; South Korea continues to report comparatively high industrial accident rates among OECD countries. To strengthen managerial accountability for worker safety, the Korean government enacted the Serious Accidents Punishment Act (SAPA) in 2021, effective January 2022. The Act institutionalizes corporate responsibility for occupational safety through compliance-based governance. SAPA was implemented in phases, initially covering enterprises with ≥ 50 employees and construction projects exceeding 5 billion KRW. This selective enforcement created a quasi-experimental setting to evaluate early effects. We assessed differences in short-term patterns of occupational injury, disease, and fatality rates between enterprises covered and not covered by SAPA during its initial enforcement phase. METHODS: We analyzed nationwide industrial accident statistics for 2017-2023 using a difference-in-differences (DID) design. Injury, disease, and fatality rates were stratified by enterprise size and industry to compare outcomes between enterprises covered and not covered by the law. RESULTS: From 2017 to 2023, occupational injuries and diseases increased, whereas fatalities declined slightly. DID estimates showed no statistically significant nationwide reductions in injuries or fatalities after SAPA enforcement began. However, disease rates declined significantly in construction (β = -0.067; p < 0.015), suggesting differentiated effects across industries. CONCLUSIONS: During the limited enforcement phase (2022-2023), SAPA did not immediately reduce nationwide accidents but showed early improvements in disease prevention in high-risk sectors such as construction. Although immediate effects were limited, continued monitoring and expanded coverage are essential to evaluate long-term impacts on worker health and safety. Findings underscore the need for integrated policies that couple legal accountability with preventive safety capacity-building.