He added that there would be lots of problems with using hydrogen sulphide in clinical practice because it was so toxic.

BBC: NEWS | Health | Gas induces 'suspended animation'

On Tuesday, state pathologist Prof Jack Crane said the levels of hydrogen sulphide and other toxic gases were high enough to render the men unconscious.

BBC: Noel (L), Nevin (centre) and Graham Spence (R)

Low doses of hydrogen sulphide, a gas which smells like rotten egg, can safely reduce the metabolism of mice, putting them into a state of suspended animation.

ECONOMIST: Researchers find hydrogen sulphide can lower metabolism

The inquest was told fumes, including hydrogen sulphide, would have been emitted in such vast quantities with the slurry that anyone in its path would have collapsed almost immediately.

BBC: Essex farm workers 'overcome by slurry'

The mice's consumption of oxygen and production of carbon dioxide dropped ten minutes after they began inhaling hydrogen sulphide and remained extremely low as long as the gas was administered.

ECONOMIST: Researchers find hydrogen sulphide can lower metabolism

Warren Zapol, of the Massachusetts General Hospital and a professor of anaesthesia at Harvard Medical School, along with his colleagues, monitored the vital signs of mice exposed to low-dosages (80 parts per million) of hydrogen sulphide for several hours.

ECONOMIST: Researchers find hydrogen sulphide can lower metabolism

Dr Fumito Ichinose, assistant professor of anaesthesia at Harvard Medical School said that if the effects of hydrogen sulphide was confirmed in larger mammals it could be useful in helping to sustain the functionality of organs in patients undergoing cardiac surgery or in patients with severe trauma.

BBC: NEWS | Health | Gas induces 'suspended animation'