Daniel Radcliffe isn't the first actor to suffer a severe injury when shooting a film, but he may be the only person who has accidentally poisoned himself while on set, and is rather lucky to have not caused any serious damage.

Daniel Radcliffe
Radcliffe drank antifreeze while filming in Canada

The "Harry Potter" star appeared on 'Conan' on Thursday (Nov 6th) to discuss his new movie 'Horns,' which was filmed in Canada, and revealed he became "horrendously ill" after having a drink of "non-potable" water.

"It is very cold in Canada and as a solution to that, they don't want the water to freeze in the pipes in the trailers overnight, they put antifreeze in it," Radcliffe explained to host Conan O'Brien. "So it's all non-potable water that comes out of the tap."

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But prior to having a sip of the poisoned liquid, the British actor was unaware of this procedure.

"I did not know that, so I drank a full cup of non-potable water," he continued. "So I guess like half-antifreeze or whatever it would have been."

"That can kill you!" O'Brien exclaimed.

Fortunately Radcliffe didn't die, and so far there hasn't been any long term effects, but it wasn't until several weeks later he was informed about the poisonous water.

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"I got horrendously ill and didn't know why I had become so ill, and a couple of weeks later I went to drink a glass of water in hair and makeup and they were like, 'What are you doing? Don't do that, that's crazy you can't drink that water!" he said.