"Acetone peroxide (triacetone triperoxide, peroxyacetone, TATP, TCAP) is an organic peroxide and a 
primary high explosive. It takes the form of a white crystalline powder with a distinctive bleach-like odor.
"It is susceptible to heat, friction, and shock. The instability is greatly altered by impurities, including its own oligomers. It is normally fairly stable when pure trimer. It is not easily soluble in water. It is more stable and less sensitive when wet."
"'Acetone peroxide' most commonly refers to the cyclic trimer TCAP (tri-cyclic acetone peroxide, or tri-cyclo, C9H18O6) obtained by a reaction between hydrogen peroxide and acetone in an acid-catalyzed nucleophilic addition.[5] The dimer (C6H12O4) and open monomer are also formed, but under proper conditions the cyclic trimer is the primary product. A tetrameric form was also described.[6] In mildly acidic or neutral conditions, the reaction is much slower and produces more monomeric organic peroxide than the reaction with a strong acid catalyst. Due to significant strain of the chemical bonds in the dimer and especially the monomer, they are even more unstable than the trimer."