The suspect in the attempted bombing of Northwest Flight 253 used a highly explosive substance called PETN, a law enforcement official told CBS News Saturday.

PETN (Pentaerythritol tetranitrate) is a high-grade explosive used for commercial and military purposes.

PETN, which usually is a white powder, can be ignited with a hammer blow and is often used by itself as a detonator.

Virtually odorless, it is very difficult to detect, making it the terrorist weapon of choice.

ABC News reports that the device involved more than 80 grams of PETN (about 3 ounces).

For reference, investigators suspect that 11 ounces of Semtex (mostly PETN) was used to bring down Pan Am103 in 1988.

Richard Reid, the “shoe bomber” who tried to bring down American Airlines Flight 63 on Dec. 22, 2001 had 8 or 10 ounces of easily-made triacetone triperoxide (TATP) and PETN (detonating cord).

Reid’s shoe was supposed to be detonated by a fuse, which failed to light, but an FBI-DHS report cited by Time magazine  notes that “TATP or HMTD may be placed in a tube or syringe body in contact with a bare bulb filament, such as that obtained from inside a Christmas tree light bulb, to produce an explosion. … Terrorists have used peroxide-based explosive both as a main charge (weighing in excess of 20 pounds) and improvised detonators.”

In the Flight 253 attack, PETN appears to have been used as a secondary explosive with the syringe apparently serving as primary.

Witnesses described the syringe as “smoking.” The Nigerian suspect accused in the attack was trying to ignite the PETN with some sort of hot liquid in the syringe.

Since PETN’s autoignition temperature is 190 degrees (far less than a match) and the suspect suffered burns exactly why the device didn’t explode is a bit of a mystery.