GM technology is an essential part of biomedical and life science research, with in general a long history of safe use in laboratories. It is a legal requirement in Hong Kong to ensure that any GM use in microorgansims, animals or plants remains contained, and ‘lab-leaks’ are prevented. This briefing will cover the legal requirements regarding GM use in Hong Kong, some specific examples where GM technology demonstrated the potential to cause severe harm in ways that were not predicted in advance, and a framework for evaluating the risks associated with GM work.