A HUGE clean up operation is going on in Djibouti following a spillage of toxic chemicals shipped from the UK and bound for Ethiopia.

Lloyd's List said that at least 20 port workers had already fallen sick as a result of the spillage, which occurred last month, although details have only now started to emerge.

More than 200 tonnes of the chemical, which is used primarily as a wood preservative for power and telegraph poles, were being shipping from CSI Wood Protection, based in Widnes in England, to Ethiopia via the Ethiopian Shipping Line.

It is said that 10 of the containers spilled, contaminating a considerable area of Djibouti port and necessitating a massive clear up operation that is being undertaken by the UN Food and Agriculture Organisation.

FAO has set aside $100,000 to pay for the clean-up operation and now wants to know the cause of the spillage.

A FAO spokesman said that previous shipments of the chemical had used steel drums for the products, not plastic, and there had been no earlier leakages.

But the UK company said that the plastic containers were approved for the product by the United Nations.

A spokesman acknowledged that the spillage was a "catastrophe," but said that the cause was still "a mystery."

The shipment was to be made to the Ethiopian Power Corporation. Lloyd's List said that preliminary investigations had revealed that the spillage had probably occurred while the containers were on the ship and the possible cause was that they had been stacked too high, causing the lower ones to split under. The worst affected site in Djibouti is within 400 metres of a food store and there remain concerns for the health and safety of dock workers.

Earlier, FAO, had warned that about 200 tonnes of the toxic substance stored at the port of Djibouti posed a serious threat to human health and the environment.

The chemical, chromated copper arsenate, is primarily used as a wood preservative for power and telephone poles.

The chemicals, which FAO says is dangerous to the environment, was shipped last year from Britain to Djibouti to be delivered to the Ethiopian Power Corporation.