A Systematic Review of the Definitions for Social Robots in Regulation and Its Implications for Researchers and Developers

Social robots are increasingly present in homes, schools, and care settings, but in regulations and international standards they are typically classified as mobile service robots (MSRs). What qualifies as an MSR varies across jurisdictions and standards, creating definitional ambiguity with practical safety consequences: for example, Paro, the robotic seal, is classified as a medical device in the U.S. but treated as non-medical in the EU, complicating which safety requirements apply. This problem is amplified by ongoing changes in standards, including ISO 13482’s shift from ‘personal care robots’ (2014) to broader ‘service robots’ in the 2024 draft. To support clearer hazard analysis, testing, and oversight, we systematically review MSR definitions in research and standards and map resulting misalignments. Using PRISMA, we synthesize recent literature and compare it with ISO 13482:2014, the revised ISO/DIS 13482:2024, and ISO 8373:2021 on robotics vocabulary. Our results show that vulnerable groups, especially children, older adults, and pregnant women, remain insufficiently protected; emotional and cognitive risks are rarely specified; and standards continue to emphasize physical hazards. Many robots described in the literature do not clearly align with ISO MSR criteria, creating uncertainty for hazard analysis and conformity assessment. Based on these findings, we propose a refined MSR definition incorporating diverse embodiments, services, and social interaction.