The missing box containing radioactive material hadn't been found as of Tuesday.

The citywide search for the dangerous equipment continued since it disappeared from an unattended company truck in Jinshan District on Saturday.

The producer of the missing cylinder said that human lives were only at risk if the sealed container that holds gamma radioactive material was broken by force.

Inside the alloy box is a 9-kilogram cylinder container that secures a selenium chip, the radioactive source that generates gamma-rays used to perform industrial radiography called non-destructive testing.

An expert, surnamed Ding, from the company in Haimen, Jiangsu Province said they had set five locks in the cylinder.

Special conduits must also be installed on both sides of the cylinder to successfully remove the tiny selenium chip, Ding said.

Ding analyzed the photo and said the conduits were not attached to the box. This means even if the keys were left inside the box, the cylinder would still be impossible to open normally.

However, the producer confirmed that strong forces could break the container and expose the deadly radioactive material. "Unpredictable" results would occur if that happened, the producer said.

An employee from Tongyong Non-Destructive Testing Company allegedly lost the box on Saturday. He left it unattended in a company truck outside his residence. When he returned four hours later, the box was gone.

Tongyong has offered a 10,000 yuan (US$1,200) reward for the return of the equipment or clues to its whereabouts.

(Shanghai Daily June 2, 2004)