Metal breakouts are still a serious problem; they may be a cause of injury or death and generally result in loss of production and damage to the furnace and its ancillaries. Their frequency has been greatly reduced by the application of science, but their precise cause frequently remains a mystery because the escaping metal usually destroys the evidence. Two main factors have been identified, namely, the limitations of refractories, e.g. inadequate slag resistance or excessive shrinkage, and improper furnace operation. The progress made towards a general solution will be illustrated by examples drawn from the iron and steel industry, a major conclusion being that men are as important as materials. In conclusion it will be suggested that the present trend towards continuous processes is likely to be attended by new risks due to the replacement of big cranes and ladles by pumps, pipes and valves demanding refractories better than are at present available.