§ The Countess of Marasked Her Majesty's Government:
At what rate they would expect the organophosphate fenitrothion applied to waxed canvas material to break down (a) when exposed 21WA constantly to the elements; (b) when exposed intermittently to the elements; and (c) when kept folded and contained in bags in a confined space; and
At what level they would have expected the organophosphate fenitrothion to have been present in the tent tested by the Laboratory of the Government Chemist (referred to in the letter to the Countess of Mar from the Assistant Private Secretary to the Minister for the Armed Forces dated 9 October 1997) at the time of the tent's purchase in 1993, assuming that it had not been exposed to the elements since the application of the chemical, and at what concentration the chemical would originally have been applied.
§ The Minister of State, Ministry of Defence (Lord Gilbert)Organophosphate compounds which have been applied to any surface will normally break down over a period of years. The rate at which this process takes place depends on many factors, such as moisture levels, temperatures, acidity or alkalinity, and sunlight. The breakdown process may be delayed if the compounds are used on material that has been treated with a wax finish, as was the case for the tent section tested by the Laboratory of the Government Chemist.
In the absence of any data concerning environmental factors, it is not possible to provide an accurate assessment of the levels of fenitrothion that would have been present on the tent in 1993, or to estimate at what rate fenitrothion would break down under the conditions given in the examples described. There is no evidence, however, that either in 1993, or during the Gulf conflict itself, the health of any individuals has been damaged by their having come into contact with pesticide residues on these tents.
The formulation of the fenitrothion-based pesticide which was made available to British troops during the Gulf conflict was a 40 per cent. emulsion concentrate. One part of this concentrate was diluted with 40 parts water and, when applied to tentage, the diluted solution was used at a rate of approximately 4.5 litres per 100 square metres.