jimvela - 10/1/2007 6:50 PMIt is my understanding that it is due to pure H2O2 being very hazardous, much like the reason that they don't allow hydrazine...
A.3.9.1 The following fuels and oxidizers shall be considered safe for operation at the Competition Venue: ethane, ethyl alcohol, gaseous oxygen, hydrogen, H20, H202 in concentrations less than or equal to 70%, isopropyl alcohol, kerosene, liquid oxygen, methane, N20, propane, butane.A.3.9.2 The following fuels and oxidizers shall be considered unsafe for operation at the Competition Venue: H202 in concentrations greater than 70%, nitric acid, hydrazine, unsymmetrical dimethylhydrazine, monomethylhydrazine, any hypergolic propellant combination.