Australian scientists improve our understanding of how peroxides destroy chemical warfare agents. 

Peroxides are efficient and effective chemicals for chemical warfare agent decontamination, both in solution or as a vapour.  Although these chemicals are widely used, the way that they work - their reaction mechanisms - are not well understood.  Now Andrew McAnoy, at the Defence Science and Technology Organisation, Melbourne, and Stephen Blanksby and colleagues at the University of Wollongong have identified the reaction pathway for the perhydrolysis degradation reaction.

The chemical reaction between the chemical warfare agent stimulant, dimethyl methylphosphonate, and the hydroperoxide (HOO-) anion was carried out in the gas phase with surprising results.  'What we observed was a chemical reaction, the -effect, which for the last twenty years has been widely accepted as impossible to observe in the gas phase,' says McAnoy. 

The -effect refers to the enhanced reactivity of an atom which occurs because an adjacent atom has lone pair electrons. 'It is this enhanced reactivity which is believed to be responsible for the efficient, and sometimes selective, degradation of chemical warfare agents,' says McAnoy.  

McAnoy describes the research as an important link between theoretical and experimental chemistry. However he recognises there are challenges to be overcome. 'These gas phase reactions have still to be linked to degradation processes taking place on the lab bench and ultimately in the field,' he says. 'If this can be done then existing technologies can be improved and new, better technologies developed.'   

'Vaporous peroxide-based decontaminants have the potential to clean up buildings, vehicles and even small electronic equipment following chemical or biological contamination,' McAnoy says. 'Indeed, vaporous hydrogen peroxide was used in some of the remediation work that followed the 2001 anthrax attacks in the US.'

Janet Crombie