So, if red phosphorus is re-heated at a high temperature, say like it survives a 'barn burner' of a fire, does it adopt some of its origional properties as yellow phosphorus? That is what SWIM has read in other documentation recently. SWIM is no more than your average 'chem-hack', but someone is trying to tell him that the red never survived a fire, but instead is full of chromium dioxide and that is why it is so volitile at room temperature and has 'charcoal' bits mixed in it. Now SWIM is no idiot. He knows that was his barrel of RP that he 'extracted' from the pile of ash and rubble. He knows through his loss of equipment and lack of funds that the fire really did happen. He also knows that the person trying to convince him of this 'chromium dioxide' tainting, is an uneducated, 'monkey see, monkey do' clown that is trying to cover his own ass on a mistake of his own. Any help in this subject would be appreciated.

Red phosphorus: Yields the white modification when distilled at 290 deg. Catches fire when heated in air to about 260 deg and burns with formation of the pentoxide.  Burns when heated in an atmosphere of chlorine.

What does sulphuric acid do to it? SWIM thinks someone may have switched his HI (57%), for H2SO4 when he wasn't around. They both have very similar weights and smells, and even looks.....(but not reactions!). Any knowledge or suggestions for such a situation?

It depends on the concentration. Concentrated H2SO4 might destroy it, but diluted will do nothing.

In regard to your comment below about H2S04 and red phosphorus:

They both have very similar weights and smells, and even looks.
Bullshit.

HI and H2SO4 neither look or smell anything alike!