Some explosives are mixtures of chemicals that do not react and are known as composites.
Composite explosives generally have oxygen balances that are closer to the ideal case of zero. Here are the mixtures used for some common composite explosives:
A common example is composite B-3 which is made up of a 64/36 mixture of RDX (C3-H6-N6-O6) and TNT.
If written in the same notation, it would be:
And would have an oxygen balance, OB = -40.5%.
ANFO which is a 94/6 mixture of ammonium nitrate and fuel oil has a -0.6% oxygen balance.