ANFO (Ammonium Nitrate Fuel Oil)
Definition
A low-sensitivity bulk explosive mixture of prilled ammonium nitrate (94 per cent by weight) and fuel oil (6 per cent). The primary explosive in the Oklahoma City bomb. Commercially available as a mining explosive; its use in VBIEDs prompted regulatory review of ammonium nitrate access across the US, EU, and India.
- Primary use
- Commercial mining and construction blasting agent
- Composition by weight
- 94% ammonium nitrate prills, 6% fuel oil
- Detonation velocity
- 4,500-6,000 m/s
- Key detection method
- Ion chromatography for NH4+ and NO3- residues
Common questions
What's the composition of ANFO?+
ANFO is a binary mixture of 94% ammonium nitrate prills and 6% mineral diesel fuel oil. The ammonium nitrate can be commercial mining-grade or agricultural-grade, though improvised versions often use lower-sensitivity agricultural prills.
How is ANFO detonated?+
ANFO has near-zero oxygen balance and low sensitivity on its own. It requires a booster charge or detonator to initiate detonation. When detonated, it produces detonation velocities of 4,500-6,000 m/s.
How do forensic chemists detect ANFO residues?+
Post-blast analysis uses ion chromatography to detect the characteristic chemical products of ANFO detonation: ammonium ions (NH4+) and nitrate ions (NO3-).
Related terms
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- EU Regulation 2019/1148
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- Anti-Handling Device (AHD)
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- Blast Seat
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- Chapman-Jouguet Pressure
- The detonation pressure at the reaction zone/product interface in a steadily propagating detonation. For ANFO at operational density, approximately 5 GPa (versus...
- Command-Initiated Switch
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Explained in these topics
- Homemade Explosives: TATP, HMTD, Urea Nitrate and Precursor ControlA binary explosive mixture of porous ammonium nitrate prills (94% by weight) and mineral diesel fuel oil (6%). Widely used in commercial mining and constructio...
- Improvised Explosive Device Anatomy and TriageA widely used commercial and improvised blasting agent consisting of AN prills soaked in or mixed with fuel oil; the main charge in several major vehicle-bomb...
- Improvised Explosives: TATP, ANFO, Urea Nitrate and Modern IEDsAn improvised and commercial blasting agent consisting of 94% ammonium nitrate prills mixed with 6% fuel oil. Near-zero oxygen balance. Detonation velocity 4,5...
- Major Bombing Casework: Oklahoma, Mumbai, 7/7, Boston, ManchesterA low-sensitivity bulk explosive mixture of prilled ammonium nitrate (94 per cent by weight) and fuel oil (6 per cent). The primary explosive in the Oklahoma C...