NIST didn't forget to test for explosives, they followed the evidence and there was no evidence for explosives bringing down an unfought fire after almost seven hours of burning.
Once I get a suggested lab or two to test the dust I will tell Kevin Ryan all about it. Since I'm researching this from the ground up, I don't yet even have proof that there IS an easy test for thermites. Once the labs respond I'll know more.
Good point. Let me consider here only differential scanning calorimetry (DSC) as an analytical method and epoxy resins as "rivals" to thermites since epoxy resin was provingly used as a binder in red primer paint used for WTC floor trusses.
As I have found in the literature and have discussed in Oystein′s "paint thread" (e.g. see
here , p 209-231),
common polymers including epoxy resins (e.g. binders in paints) are usually rapidly degraded in the range ca 360-430 degrees C not only under air, but also under nitrogen. So, even DSC measurements under inert atmosphere cannot (in principle) distinguish thermitic reaction from other exothermic processes connected with the degradation of the epoxy binder. This must be taken into account.
On the other hand: Common polymers (including epoxies) rapidly degrade mostly in the region fairly below 500 degrees, where thermitic reaction is not observed even for "nanosized thermites". It is shown
here
Fig 7.1, that "onset temperature" of thermitic reaction could be even below 500 degrees C, but this may be valid only for extremely fine aluminum particles of the sizes below ca 10 nm.
As regards "shapes" of DSC curves, it must be noted that polymer degradation is seldom investigated by DSC, since this method is not suitable for processes accompanied with the great loss of mass. Anyway, you can find some DSC curves for epoxies in the linked article from books.google (e.g. Fig. 8).
As you can see, for epoxies, almost complete loss of mass (overall exothermic process) occurs in the range ca 100 degrees (heating rate 10 K/min), even under nitrogen. Degradation under air (thermal-oxidative degradation) has the similar rate. This rate is comparable with the rate of burning of real nanothermite in Bentham paper. So no big difference between thermal degradation of epoxy and burning of nanothermite can be expected here... (Basically, DSC measurements should be done in isothermal mode and even real thermites can "burn" quite slowly at these conditions).
In conclusion: I think that only the positions of observed DSC exotherms can be taken as some proof that we are dealing with epoxy binder/thermite. For thermites, exotherms should lay above 500
oC, for epoxy binder, those should lay slightly below 400
oC.