Chemistry and inclusion control are two of the main keys to the production of quality steel products. The refractory materials have a direct influence on the quality of elaborate grades at different levels: (i) The control of solute elements such as carbon, sulphur, nitrogen, hydrogen, oxygen. (ii) The prevention of non-metallic inclusions. A good knowledge of the metal-slag-refractory products interactions is consequently necessary in order to have a better control of elaboration procedures. Among all the points brought up, we could mention all the developments that will limit the contribution of refractory products in clogging phenomena, carbon pick up and atmospheric re-oxidation, in conjunction with efforts of the metallurgists to produce clean steels.