Millions of French fretted Tuesday -- and some felt sick or got headaches -- after a gas leak at a chemical plant cast a strong odour that wafted from northern France as far as Paris.
Authorities insisted that the gas, mercaptan, was harmless, but emergency lines were inundated with calls from people worried about the pong that came from a Lubrizol factory in the Normandy city of Rouen.
The company said Tuesday it should within hours be able to plug the leak that began a day earlier and whose odours were blown by winds as far as the streets of the capital, over 100 kilometres (60 miles) away.
Despite the official insistence that the leak was not dangerous, French social media were awash with people in the affected regions complaining of headaches and nausea from the gas that smelled like rotten eggs.
"They're all saying not to panic, but they said the same thing about the cloud from Chernobyl," said mother of four Patricia Cousteau, referring to radioactive fallout that spread across Europe in 1986 after an explosion at a Ukrainian nuclear plant.
Local authorities said in a statement that a chemical substance at the Lubrizol plant, which makes additives for industrial lubricants and paint, became unstable and caused odours that are similar to those of town gas.
"The gas has an unpleasant smell but is not toxic," it said.
The concentration of the gas was also "very low", the statement said, adding that "a large number of people have been inconvenienced".