The International Union of Pure and Applied Chemistry (IUPAC) and UNESCO have proposed that the International Year of Chemistry, 2011, should make a strong educational contribution to the goals of the UN Decade of Education for Sustainable Development. This emphasis is absolutely necessary because education for sustainability remains practically absent nowadays in many high school and university chemistry curricula all over the world. Behind this lack of attention to the current situation of planetary emergency, there are several obstacles that we analyse in this paper. We firstly discuss an extended conception of "pure Chemistry"--object of chemists' research and teaching- the object of which would just be to increase knowledge: moral problems should only appear in connection to the use of the applications of science by, generally, nonscientists. This belief that genuine scientific activity lies beyond the reach of moral judgment is logically transferred to teaching, voluntarily limited to the transmission of the corpus of knowledge. Consequently, the challenges of sustainable development, with so many social implications, are put aside. After questioning this and other obstacles, we develop the possible contribution of chemistry and chemical education to the construction of a sustainable future, in accordance with the goals of the International Year of Chemistry.