Release of chemical ‘would cause fear and panic’

OSMIUM TETROXIDE is the chemical believed to be at the centre of an alleged bomb plot foiled by ‘British and American intelligence agents.

It is thought the supposed plan involved detonating an explosive device and the compound.

Andy Oppenheimer, a nuclear, biological and chemical weapons expert for Jane's Information Group, said osmium tetroxide was an unusual choice as a chemical weapon but it could kill.

He said if terrorists were going to use it they would be likely to do so in a small bomb in a confined space.

"You can't get hold of barrels of this stuff but if you were going to set off a small device and frighten people you wouldn't really require that," he said.

"You don't think of it being used in a bomb but you would get dispersal of the chemical in a bomb and in an enclosed space it would harm people. If people breathed in enough gas in an enclosed space they could die.

"I don't think there would be any point using it in a big bomb because people would be hit by the explosion."

He said the main impact of such a bomb would be to spread fear and panic.

"It would be used to up the ante, to frighten people. It's just the very idea that anything could be used even if it was a common chemical. There really is a growing threat of terrorists getting hold of this sort of material.

"With chemicals there are so many that could be used. It may just be sheer opportunism, terrorists will get hold of what they can."

Osmium tetroxide is used by scientists to stain materials and as a catalyst to speed up chemical reactions. It is also a toxic substance with corrosive effects on eyes and skin, making it dangerous to touch or inhale.

But given its high cost and volatile nature, some scientists say it makes an unlikely ingredient for an effective "dirty bomb".

Dr Steve Simpson, a senior lecturer in chemistry at the University of Salford said the yellow crystalline solid is a volatile substance because it turns from solid to gas at room temperature.

The resulting vapours corrode skin and eyes and fumes damage the lungs when inhaled. In the laboratory it is only safely handled inside a fume cupboard.

"If you get the vapour in your eyes, even a small amount, it can turn them brown or black and you could be permanently blinded," said Dr Simpson.

"It is so volatile, you would be in appreciable danger just opening a bottle. If you had 10g and you opened it up in a normal-sized room, within a couple of minutes it would cause people's eyes to stream. Some people might feel a bit tight in the chest. It would cause massive panic. You would certainly know it was there it has an acrid smell."

Osmium tetroxide is not a fatal substance but, said Dr Simpson "could cause trouble" if swallowed. However, it is so quick to react it would be hard to take most likely decomposing in the mouth. Harmful effects aside, scientists believe it is an "extremely unlikely" candidate for use in a dirty bomb.

Handling the chemical would be difficult for any terrorist. And it is expensive one gram costs about £96- £130 (€146-€198).