Possible Clues:

• Heat-resistant mineral
• Fireproof substance, dangerous to health
• Fireproof material
• A few letters of distress about the greatest footballer with a mineral that's not very fiery
• Answer distress signal sheltering top dangerous in-house material
• Mineral involved in much litigation
• Answer distress signal about most useful and dangerous in-house material
• Heat-resistant material
• TA bosses arranged protection against fire
• Danger in old homes