British scientist Professor Iain Stewart, who spent two days inside an airtight chamber inhaling oxygen produced only by plants, survived the harrowing experiment.

The experiment, which was conducted to show how vital plants are for our survival, had previously never been done with a human.

He entered the transparent chamber on Thursday night and spent time there until Saturday night.

The level of oxygen was taken down from normal 21 per cent to 12.5 per cent. Then lights were turned on to allow plants to produce oxygen through the process of photosynthesis.

The oxygen level went up, providing Stewart with enough oxygen to survive. However, he admitted that he suffered blinding headaches.

Speaking on the topic, Stewart said, "The oxygen obviously went up enough and I got through it but not without some cost."

The experiment was a part of a new BBC TV series called "How Plants Made the World".

In 1772, Joseph Priestly was the first scientist to conduct a similar experiment showing a mouse could survive in an airtight box full of plants, but dies in a box devoid of plants.