Los Angeles It's nicknamed the "Mother of Satan" explosive, it's made from a mixture of readily available and easily concealed liquids, and it's the main reason travelers have been barred from bringing all liquids and gels - from water to shampoo - on airplanes.
Law enforcement sources believe the foiled British terrorists may have been planning to mix the explosive, known as TATP, from three liquids they could have easily smuggled onto airliners in Sprite or Pantene hair-products bottles.
Once mixed, the liquids become a white, crystalline powder that, when dry, is so volatile it can explode with just the slightest friction or other heat source - no fuse or detonator is needed, experts said Thursday.
"It's very volatile. If you tried mixing it on an airplane, you could blow yourself up doing it," said bomb squad supervisor Sgt. Julio Salcido, of the Los Angeles County Sheriff's Department.
Equally ominous, the clear liquids used to make TATP, known to chemists as triacetone triperoxide, are not explosive separately. They would not rile bomb-sniffing dogs or set off airport explosive detectors geared for nitrogen-based substances.
A near recipe for the highly dangerous concoction appears in a scholarly article posted on a law enforcement Web site.
Widely used by Palestinian suicide bombers, TATP was the chosen explosive of last year's London transit bombers.