Related Clues:

• Compound in some explosives
• Fertilizer and explosive
• Atacama Desert export
• 'ASTI permutations, mainly used in fertilizer (5)'
• Potassium nitrate
• Pyrotechnics compound
• TNT ingredient
• Fireworks compound
• Stuff in gunpowder
• Constituent of gunpowder
• American mineral water in Barking but not Washington!