Related Clues:

• Fireproof material, dangerous to health
• Fire-resistant material, injurious to health
• Fireproof substance, dangerous to health
• Fibrous insulation material, dangerous to health
• 'Fireproof substance, dangerous to health (8)'
• Can't get fired like the foremost rounds, perhaps
• As it can't be bettered, so it turns out it can't be fired
• Like the best circles, no firing there
• As there are no better rounds, there can't be any firing
• The way the very good rounds can't get fired?
• Like very good rounds, will never get fired
• Cannot be fired, in the way of the rounds that are top quality
• One can't get fired in the way of the 3 down rounds
• Like the very good ones, so it's wrong never to be fired
• Like the best circles, cannot get fired