PARIS, Aug 10: As airlines banned the carrying of liquids onto planes after the suspected plot to blow up flights from Britain to the United States, experts speculated on the liquid explosive that may have been involved.

Several different kinds of liquid explosive were identified, including nitroglycerine, the best known “liquid bomb”.

The oily, yellow-coloured liquid is used in explosions on building sites and in quarries and is normally ignited with a detonator. A French explosives expert, requesting anonymity, told AFP that nitroglycerine could explode with a small detonator the size of a pen top.

The detonator could be set off by an electric shock provoked by a small battery in a portable electronic device or by a slow fuse lit with a cigarette lighter, he said.

Two or three litres of liquid components in the baggage compartment of an airplane could set off a blast that would break through the side of the plane, he added, depending on its size and where the explosive was placed.

Other liquid explosives include nitromethane or a similar alternative, nitroethane.

Another chemical, methyl nitrate, is unusual in that it will explode as soon as it is combined with another substance and does not need to be ignited by a detonator device.

“Methyl nitrate has been used as a component of an anti-personnel mine. When you step on the mine, you break a container which causes the substances to mix,” Dr Alford, chairman of the explosives company Alford Technologies, told Britain’s domestic Press Association news agency.

Liquid explosives can easily be disguised in bottles of drink or cosmetics.

“Most people associate explosives with either solid materials or gases,” Alford said. “You don’t expect an explosive to be liquid. If it’s in a baby’s bottle, or a clearly labelled bottle of gin or whisky, or cough mixture, how many security staff are going to question it?”—AFP