A gas cloud that is foul-smelling was emitted from a factory in northern France on Tuesday and has spread. The Associated Press reported that the gas cloud has spread to gone from outside Paris to Britain.

The gas is reportedly mercaptan gas that escaped from the Rouen chemical factory and France's Interior Ministry said in a statement that the gas is harmless.

"Bearing in mind the lack of danger, residents of the areas concerned are asked not to call emergency services," the Interior Ministry said.

The factory is in the city of Rouen and is owned by Lubrizol, which makes additives for industrial paint and lubricants.

"Mercaptan is a colourless additive used in natural gas because its acrid smell enables gas leaks to be detected. It is non-toxic but can be flammable in high concentrations," reported The Telegraph.

"Among other uses, mercaptan is added to otherwise odorless municipal gas to alert people of leaks. The factory has been shut down, and environmental authorities are carrying out tests," reported the AP.

The Telegraph reported that people were complaining that the smell was like "sweat, garlic and rotten eggs".

Mercaptin is also known as methanethiol. The Independent reported that the substance is  "a harmless but pungent-smelling gas which has been described as having the stench of rotting cabbages or smelly socks ... The gas is an organic substance, made of carbon, hydrogen and sulphur, and is found naturally in living organisms, including the human body where it is a waste product of normal metabolism. It is one of the chemicals responsible for the foul smell of bad breath and flatulence."

The UK's Telegraph reported that the gas stenchwent all over the channel from France to Sussex and Kent in Britain and was even reported in London which is 150 miles away from the source.

The terrible smell has resulted in a number of phone calls to police. The London Fire Brigade tweeted that  it had five times as many phone calls  as the day before about the smell before 10:30 am.

Residents of Paris and Rouen complained of nausea and headaches, reported The Telegraph.

Because of the horrific stench a French Cup football match between Rouen and Olympique Marseille was also canceled.

Lubrizol claims they are trying to stop the leak but has been unsuccessful thus far. "It's not so much a leak as a product that has decomposed, which smells very bad and which is escaping," Pierre-Jean Payrouse internal operations director at Lubrizol France said to RTL radio. "An investigation is under way (into what happened) but our priority is to deal with the problem."

Lubrizol's website states about their brand that "by formulating complex chemicals at the molecular level, Lubrizol engineers and chemists develop additives, ingredients and compounds that amplify the quality and performance of other products while reducing their environmental impact."

Their products span a wide range of applications including "lubricants and fuels, metalworking fluids, performance coatings, inks, personal care and over-the-counter pharmaceutical products, computers, sports gear, high-performance apparel, even ice cream," says the company's