Firefighters said five kilograms of sodium was produced and deposited in a cauldron at the Sichuan Sangao Biochemical Co Ltd which could have exploded and razed an area within a radius of 20 meters if it came into contact with water.

Plant employees, nearby residents, as well as students and teachers of a local high school had to be evacuated to safe locations, and traffic near the plant was stopped.

Chemical experts and officials rushed to the spot in Longquan District in Chengdu, capital of Sichuan Province, and worked out several solutions.

It was finally decided that ethanol should be put in drop by drop into the cauldron through a 50-metre-long thin pipe.

The reaction would produce a stable compound of sodium and hydrogen, and the gas would slowly discharge from the cauldron.

Nitrogen, a kind of inert gas, was continuously put into the cauldron to reduce the danger, according to plant staff.

Dozens of sandbags were also placed around the large cauldron to serve as a buffer in case an accident occurred during the reaction.

The process was completed after five hours Thursday night, and the whole reaction was said out of danger.

According to a report in a local newspaper Thursday, workers at Sangao put some 10 kilograms of sodium into a cauldron as usual on Wednesday morning, only to find that half the raw material remained on the wall inside.

To make matters worse, the sodium was in a powder form, making it highly unstable.

In a different explanation, a Sangao manager surnamed Zhao said the cause of the accident was the erroneous supply of methylbenzene rather than benzene by a raw materials company.

His staff failed to detect this, and put 13,000 kilograms of methylbenzene into the cauldron. They were soon alerted to the mistake and only one of five cauldrons at the plant was in danger.

Vice-Mayor Tang Chuanping of Chengdu and other top local leaders rushed to the location and stayed there until the threat of an accident was eliminated.

(China Daily October 11, 2002)