Letter: Diluted fertiliser or the odd bomb?

Sir: R. P. Warner's suggestion ('Bomb disposal', Letters, 30 April) that ammonium nitrate (AN) fertiliser be modified by the addition of an inhibiting substance that would prevent its usefulness as an explosive agent (as he may know has already been done in this country with the weed killer sodium chlorate), deserves a response.

There are two main difficulties. First, the amount of inert diluent required to achieve the desired effect is so great that farmers would be buying and applying to their fields almost as much diluent as ammonium nitrate.

Second, the great difference in solubility between ammonium nitrate and suitable diluent substances is such that large-scale separation of the two by fractional crystallisation is a very simple business.

These disadvantages have nevertheless not been sufficient to prevent prohibition of undiluted AN in Northern Ireland and the Republic of Ireland for about the past 20 years.

On this side of the Irish Sea, the Government considers causing annoyance to the farmers and landowners by depriving them of the fertiliser to which they have been conditioned by the fertiliser industry as a greater inconvenience than the odd bomb or two in London.

Indeed, their official line is that AN is not an explosive at all but a mere 'oxidising agent'.

Even after the Baltic Exchange bomb, the explosives inspectorate of the Health and Safety Executive (whose function I for many years wrongly believed to be health and safety, but now realise is the execution of the Government's policy on health and safety, which is sometimes very different) went as far as to state that 'fertiliser grade am-

monium nitrate is not a security

problem'.

Yours faithfully,

SIDNEY ALFORD

Sidney Alford Ltd,

Explosives Engineering

Corsham,

Wiltshire

1 May