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Irresponsible leaking of information

Dear Reader,

When I read the Guardian this morning it come to my attention that Mike McCaul in the USA has made a statement regarding the explosive which the Manchester bomber used. He stated that the bomb contained acetone peroxide. I think that this was a very bad thing to do as it limits the ability of the British authorities to deal with the criminal or criminal network which is behind this outrage.

I am not sure quite how fast the forensic workers can work, I also wounder how accurate the results which he leaked were. Fox news has claimed that a bomb making workshop was found during a raid recently,

I have to also ask the question of “need to know”, what does the public need to know about the bombing. The public should be told that a bombing has occurred and that the police and other parts of the state are dealing with it. But I would argue that the public do not need to see photographs of the wreckage from the bomb or know technical details of the bomb at this stage. I have to ask the question of what good does it do to tell the public the identity of the explosive.

I can not see a reason or purpose right now, I could understand it coming out during the trial of a bomber. My own view is that the trials of bombers should occur in open court, but during those sections of the trial when the design of the bomb is discussed these sections should be held in camera. My reason is that I would rather that the next generation of bombers do not get an education on bombs by attending (or reading about) a trial where bomb design is considered and discussed.

Now the cat is out of the bag, I see no point in not discussing some aspects of the explosive here. The explosive in question is a rather rare one, it is nitrogen free. Many explosives (TNT, ANFO, Picric acid, RDX, nitroglycerine) contain nitrogen. One of the driving forces for the detonation is the formation of nitrogen gas. A typical explosive contains both a fuel and an oxidant. In the case of TNT the fuel is the methyl group and the aromatic ring while the oxidant is the oxygens in the nitro group.

In the case of the London Tube / Bus bombings and the Manchester concert bombing it appears that the bombers used combinations of an organic fuel and peroxides to build their bomb. In the interests of public safety I will not be giving any details of how to make explosive organic peroxides. I hold the view that the UK is going in the right direction with the law on explosive precursors (Control of Poisons and Explosives Precursors Regulations 2015). This law restricts the sale and possession of chemicals such as hydrogen peroxide. The current limit in the law for hydrogen peroxide without a license is 12 % w/w. This is a rather strong solution compared with what is needed for bleaching hair and other household uses.

If we assume that the density of 12 % hydrogen peroxide is 1 gram per ml, then 1 litre of such a solution will contain 120 grams (3,53 moles) of hydrogen peroxide. This would generate 1.76 moles of oxygen gas if it was decomposed totally which would have a volume of 42 litres. An old fashioned way to express the concentration of hydrogen peroxide is to state the number of litres of oxygen which would be generated by the total decomposition of 1 litre of the hydrogen peroxide solution. When I was a boy I used to buy 30 vol hydrogen peroxide to use in my chemistry experiments which I did in the shed. I had set out to buy 20 vol hydrogen peroxide but I found out that the chemist sold 30 vol hydrogen peroxide instead. I once bought some 50 vol hydrogen peroxide, this would now come under the UK law which I mentioned above.


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