Board Thread:General Discussion/@comment-4161952-20130331221843/@comment-5675229-20130402023718

SenNoKuroiHonoo wrote: Self-Destruct mechanism implanted in them by Aizen using Hogyoku to prevent corpse-study? Come on man, we must come up with an answer!

On the other hand, Szayel's heart was pierced by Mayuri so does it counts as a mortal wound? If mortal wounds trigger their "dusting", maybe Tosen's explosion was also a result of having received mortal wounds.

Nah, being impaled in the head by a two-sided blade is not a mortal wound. Aizen survived being cut in half by Mugetsu, why would Tosen not survive that? =P