Institutional graduate capabilities and discipline threshold learning outcomes require science students to demonstrate ethical conduct and social responsibility. However, the teaching and assessment of these concepts are not straightforward. Australian chemistry academics participated in a workshop in 2013 to discuss and develop teaching and assessment in these areas, and this paper reports on the outcomes of the workshop. Controversial issues include: How broad is the mandate of the teacher, how should the boundaries between personal values and ethics be drawn, and who determines what constitutes social responsibility? In this position paper I argue for a deep engagement with ethics and social justice, achieved through case studies and assessed against criteria that require discussion and debate. Strategies to effectively assess science students' understanding of ethics and social responsibility are detailed.