Ok, I did some searching....
Kerosene and JP fuels are largely the same. It's more or less the additives and blending that changes them. JP5 and JP8 being almost the same, to us on the ground they're exactly the same. JP 4 is a kerosene naptha blend.
From the Single Fuel Forward Compendium
MIL-DTL-5624 describes one grade of aviation turbine engine fuel; JP-5 a kerosene fuel. Previous revisions contained an additional grade, JP-4 which was a wide-cut fuel. Where prevailing low temperatures warrant a fuel with very low temperature operability, use of JP-4 is recommended.
JP-4 is essentially a 50:50 mixture of heavy naphtha fraction (like gasoline) and kerosene. This fuel is not considered to be an acceptable substitute/alternate for diesel fuel. JP-4 is interchanged within NATO under NATO Code Number F-40. JP-4 is mainly procured as ASTM D 975 Jet B (or perhaps as CAN/CGSB 3.22). The chief difference between JP-4 and Jet B is that JP-4 contains the three mandatory additives while Jet B does not unless requested during procurement.
JP-5 is a 100% kerosene blend and is an acceptable substitute/alternate for diesel fuel. JP-5 is interchanged within NATO under NATO Code Number F-44.
MIL-DTL-83133 describes one grade of aviation turbine engine, JP-8.
JP-8 is a 100% kerosene blend and is an acceptable substitute/alternate for diesel fuel. JP-8 is interchanged within NATO under NATO Code Number F-34.
Both JP-5 and JP-8 are essentially the same type of fuel but only differ primarily in their flash point minimum requirements. JP-5 specifies a 60C (140F) minimum requirement. JP-8 specifies a 38C (100F) minimum requirement.
The higher flash point requirement for JP-5 is due to the U.S. Navy's shipboard safety requirements.
Recently completed survey on JP-8 and JP-5 fuels being suggested under contract worldwide provided following averaged properties JP-5 fuels had average flash point of 62C (144F). JP-8 fuels had average flash point of 46C (115F).
This difference in flash point requirements translates to very subtle difference in the physical and chemical characteristics when comparing JP-5 to JP-8; e.g., the average viscosity at 100F is approximately 1.5 cSt as compared to approximately 1.3 cSt for JP-8.
ASTM D1655 JET A-1 is the commercial industry standard for aviation fuel and is available worldwide. JET A-1 is essentially identical to JP-8 except that it does not necessarily contains the three additives required in JP-8. The three additives mandatory for JP-8 are
Fuel System Icing Inhibitor (MIL-DTL-85470)
Corrosion Inhibitor (MIL-PRF-25017)
Static Dissipator Additive
ASTM D1655 also includes a JET A which is the industry standard for commercial aviation turbine fuel used only within the U.S. for domestic flights. The sole difference between JET A-1 vs. JET A is in the freeze point requirement. JET A-1 specifies a -47C (-53F) minimum, whereas JET A specifies a -40C (-40F) minimum.