CYLINDERS OF hydrogen cyanide stored for decades by pest control company Rentokil have been neutralised chemically in what is believed to be the first such disposal in Ireland.
Following the process to deal with the 15kg of deadly gas, the seven cylinders have been exported for incineration in Germany.
South Dublin County Council expects to receive certificates of destruction from the German incineration specialists within the next fortnight.
A US company, Integrated Environmental Services (IES), specialists in on-site management of such gas cylinders, carried out the process at a compound owned by South Dublin County Council at Grange, Co Dublin.
The council said there was no risk to the public and the nearby golf course was closed during the neutralising process, which began early on Tuesday morning and was completed on Wednesday afternoon.
John Quinlivan, senior executive officer with the council, said yesterday the council's priority was always "to effect the safe disposal" of the chemical, without risk to the public.
He pointed out that throughout the process, monitors - to detect leaks - were placed on each of the cylinders and held by all personnel involved and there had been no venting or leaks.
Mr Quinlivan added that air, water and soil sampling at the compound, which was carried out before and during the work, would continue for the next 10 days.
Four IES personnel from Atlanta travelled to Ireland to carry out the disposal procedure and used specialist equipment flown in from the US.
The initial plan to dispose of the chemical by explosion at an Army rifle range in Kilbride, Co Wicklow provoked public outrage.
The deadly chemical, reportedly used in Nazi concentration camps, had been used as an agriculture poison, for pest control and to fumigate buildings such as flour mills as well as ships.
Rentokil, which had not used the cyanide in decades, had been storing the chemical at its Ballymount, Co Dublin site for some 40 years.
Local politicians claimed it was a "crazy plan" to dispose of the chemical in west Wicklow because the cylinders could explode during transport, especially on a country road with potholes and poor surfacing.
Mr Quinlivan stressed however that if explosives had been required for any of the seven cylinders the Wicklow range would have been used for that purpose.
He said however that the US specialists X-rayed the cylinders and found they were "substantially more stable than anticipated" and recommended that the first option should be to neutralise them chemically.
This was done by drilling the cylinders and neutralising them with reagent.
The cylinders were transported from the Ballymount site to the compound located between Lucan and Clondalkin, by a hazardous waste company.
The council is to publish details of the work done by IES as part of a case history and will make this available to other local authorities and agencies.
The cost of the operation, which involved a number of agencies, will be paid by Rentokil, which the council described as a "good corporate citizen".
The Green Party has welcomed the successful destruction of the chemical.
Wicklow Senator Deirdre de Burca said it was a relief to residents living in the Kilbride area of Wicklow.
She said the Green Party had asked the council "to explore alternative methods to neutralise the hydrogen cyanide as we were not convinced that the disposal methodologies put forward reflected the best and up-to-date environmental and health and safety practice".
