Seal, particularly for use with a ladle shroud in the casting of molten metal from a ladle, having an intumescent composition containing expandable graphite from which some, but not all, of interstitial water present therein has been removed. The interstitial water can be driven off from known expandable graphite by heating it to between approximately 230° C. and 280° C. for approximately 30 minutes. Once part of its interstitial water has been removed, the expandable graphite is used to produce the intumescent composition, which is then formed/shaped into the required seal.