Oxygen Balance
Definition
A percentage expressing the surplus or deficit of oxygen in an explosive molecule relative to stoichiometric complete oxidation of carbon to CO2 and hydrogen to H2O. Negative values indicate oxygen-deficient products (CO, soot); near-zero values indicate efficient detonation.
- TNT oxygen balance
- -73.9% to -74%
- RDX oxygen balance
- -21.6%
- PETN oxygen balance
- -10.1%
- ANFO oxygen balance
- -0.4% to ~0%
- Effect of near-zero balance
- Maximizes detonation energy output and efficiency
Common questions
What does a negative oxygen balance tell you about an explosive?+
Negative oxygen balance means the explosive molecule doesn't have enough oxygen to fully oxidize its carbon and hydrogen. During detonation, this oxygen shortage produces carbon monoxide and soot instead of complete combustion products. TNT has a negative balance of about -74%, which is why it generates significant soot and black smoke.
Why is ANFO's oxygen balance close to zero?+
ANFO is formulated with an oxygen balance near -0.4% to 0% to maximize detonation efficiency and energy output per gram. Near-zero oxygen balance allows the explosive to combust nearly completely, releasing more energy with less soot than oxygen-deficient explosives like TNT.
How do you calculate oxygen balance?+
Oxygen balance is expressed as a percentage comparing the surplus or deficit of oxygen in the explosive molecule to the amount needed for stoichiometric complete oxidation (carbon to CO2, hydrogen to H2O). The calculation depends on the molecular composition of the specific compound.
Related terms
- Brisance
- The shattering power of a detonating explosive, distinct from heave (bulk displacement). Measured by the Trauzl lead block test. High-brisance explosives (RDX,...
- Deflagration
- A subsonic combustion front propagating through an explosive by thermal conduction. Characteristic of low explosives such as black powder and smokeless powder;...
- Detonation
- A supersonic shock wave coupled to a chemical reaction front, propagating through a high explosive at velocities between approximately 4,500 and 9,100...
- Brisance (Shattering Power)
- The localised shattering effect of a detonation shock wave, measured by the Trauzl lead block test or the sand-crush test. RDX and...
- C-4
- US military standard plastic explosive containing approximately 91% RDX in a di(2-ethylhexyl)sebacate and polyisobutylene binder. White, odourless, malleable. Detonation velocity 8,050 m/s....
- Chapman-Jouguet Velocity
- The minimum stable detonation velocity for a given explosive at a specific density, a thermodynamic property of the explosive composition. Used to...
- Composition B (Comp B)
- A secondary high explosive formulation of 60% RDX and 40% TNT by mass, melt-cast from the TNT matrix. Used in artillery shells,...
- Critical Diameter
- The minimum charge diameter below which a detonation wave cannot sustain itself, because energy losses to the sides of the charge exceed...
- Detonating Cord
- A cord with a PETN explosive core (5-40 g/m) that detonates at approximately 6,400 m/s when initiated. Used to connect multiple charges...
- Detonating Cord (Det Cord)
- A flexible tube containing a PETN explosive core at a standard linear charge density (3.6 g/m for No. 2 cord). Propagates detonation...
- Detonator
- A small initiating charge of primary explosive (lead azide, lead styphnate, mercury fulminate or DDNP) that converts an electrical, mechanical or pyrotechnic...
- DMDNB
- 2,3-Dimethyl-2,3-dinitrobutane, the primary detection taggant mandated by the 1991 ICAO Convention on the Marking of Plastic Explosives. Required at 0.1% by mass...
Explained in these topics
- Conventional High Explosives: TNT, RDX, PETN, HMX, Composition B, C-4 and SemtexThe percentage surplus or deficit of oxygen relative to stoichiometric complete oxidation in an explosive molecule. TNT (-73.9%) produces significant CO and so...
- Explosives Classification: Low vs High, Primary vs SecondaryA percentage expressing the surplus or deficit of oxygen in an explosive molecule relative to stoichiometric complete oxidation of carbon to CO2 and hydrogen t...
- Explosives: Definition, Types and ClassificationThe percentage excess or deficit of oxygen relative to that required to oxidise the carbon, hydrogen and metals in the explosive fully. RDX has oxygen balance...
- Specific Explosives: TNT, RDX, PETN, HMX, ANFO, TATP, Urea NitrateA measure of the excess or deficit of oxygen in an explosive compound relative to full oxidation of carbon to CO2 and hydrogen to H2O. Negative oxygen balance...