While researching the clinical and biophysical aspects of Sodium Thiosulphate Na2S2O3 (photographers "hypo") as a CN antidote, I came across this tidbit I'd never seen mentioned before:

3.3.10 Incompatibility

Incompatibility with iodine, acids, lead, mercury and silver salts (Windholz, 1983) and with salts of heavy metals, oxidizing agents, and acids has been indicated. If sodium thiosulfate is triturated with chlorates, nitrates, or permanganates, an explosion may occur (Martindale, 1989).

No definitive information here, but the statement raises some interesting questions. Granted there are many substances that can explode when combined or ground together in a mortar (chlorates and sulphur being one of most notorious combinations), but what is it about common hypo that will trigger an energetic reaction with nitrates and permanganates? Just how energetic is this sort of reaction likely to be, and more importantly, can it be exploited somewhere in an explosive train, even as an auto-igniter, or is the reaction merely a low-energy "novelty" that merits a warning to lab personnel but has no practical application?

I guess the only way to find out is to.... find out... by trying it :p
Of course thats obvious :rolleyes:

For safety reasons, only try a sample of a few grams of the mix.
I would do it myself, but i lack Na2S2O3.

Would this reaction occur with all thiosulfates, or is it only with certain thiosulfates (say, the alkali metals).

Maybe if it proves powerful enough it could have certain applications in expedient devices.

It's because of the sulfur impurities reacting with the chlorate. Nothing astonding.

As for nitrates, it's likely along the lines of a gunpowder reaction, with an oxidizer/fuel combo being locally heated by compression/friction.