In the wrong mix, the chemical simply killed the subject.

But the doctors said they did not know how the chemical could have killed so many liver cells so quickly.

The chief obstacle to wider use is that the chemicals can kill many of the crops they might be protecting.

In sufficient quantities, such chemicals can poison and even kill the bee.

The chemicals break down the faeces and obviously kill any bacteria present.

Some chemicals in graviola may also kill cancer cells directly.

"They couldn't find anyone to inject the chemicals to kill him."

But at lower doses the chemicals may not kill or irritate cells and so will be harmless.

But too few photographers realize that chemicals used in making shoe boxes could be killing their images.

"These chemicals either kill you or they leave you alone, without any consequences," he said.