Twelve shipping containers packed with dangerous chemicals were still missing yesterday after falling into the rapid current of the Yangtze River on Monday.

Four ships sent out by the Three Georges Maritime Administration have been searching the river since a Shanghai-bound cargo ship lost 62 containers as it tried to accelerate in the lower part of Three Georges, near Yichang city, Hubei province.

Six of the crates held potassium permanganate, usually used as a disinfectant; five carried potassium hydroxide, a toxic chemical used in fertilizers and soaps; and one held sodium permanganate, which is used to make circuit boards.

Three containers loaded with metal doors, pickles and other food products were recovered from the surface of the river during the first phase of the search, Peng Xinyan, an official from the administration, said.

The next phase will focus on the bottom of the river and try to locate the remaining 59 containers by sonar. A detailed salvage plan will be discussed once they have been found, Peng said.

"If there wasn't a heavy collision when they fell, there is a only a slight possibility for the chemicals in the containers to leak," Peng added.

But He Gang, director of the emergency office with Yichang government, is more concerned about the poor packaging of the chemicals and the possibility of leaks developing in the containers, some of which may be 80 to 90 m deep.

"The containers probably won't sink to the bottom if they are sealed water-tight," he told China Daily yesterday.

Environmental officials in Yichang city have been testing the water quality downstream for contamination.

Crew members from the cargo ship have been detained for further investigation, according to He.

(China Daily August 13, 2009)