§ Mr. LivingstoneTo ask the Secretary of State for the Home Department what evaluation of the medical effects of the CS gas solvent, methyl isobutyl ketone, has been made by officials of his Department and the police scientific development branch since 1990; how many published or internal reports have been written by his Department on this subject since 1990; and how many of these reports are currently unclassified. [12180]
§ Mr. MichaelThe Home Office police scientific development branch, together with the Department of Health and the Ministry of Defence, fully evaluated all scientific data relating to methyl isobutyl ketone, MIBK, before police trials of CS spray canisters containing this solvent were conducted last year. The Home Office has not produced any reports, either internally or published, about MIBK.
The ideal solvent for use in CS spray will present no risk to health—in particular, the eyes—and will evaporate as soon as it has done the job of delivering the CS irritant to the target. I am told that MIBK is the solvent which comes closest to achieving this. It occurs naturally in oranges, grapes and vinegar. It has many applications, including use as a food additive. It has been used in CS sprays in France for many years without serious difficulty: in particular, extensive research there has shown that it has a low toxicity to the eyes. Its only drawback is that it has a relatively low volatility, which means that it remains on the skin of someone sprayed for a short time before evaporating and may cause de-fatting and blistering.