Giant bottles of Chanel No. 5 perfume are arranged in the shape of the number five at the Royal Palace in Antwerp, Belgium.

London - Chanel No 5 perfume, the top-selling perfume in the world - a bottle is sold every 30 seconds - is under threat.

The reason? One of its key ingredients - a type of tree moss which imparts an earthy, woody scent - has come under the microscope of a team of EU scientists who believe it may cause allergies.

Under rules implemented by the European Commission in 2006, 26 common ingredients including tree moss and eugenol (found in rose oil), must be declared on the packaging of perfume because they are potentially allergenic.

Now it has emerged that the Commission’s Scientific Committee of Consumer Safety, charged with protecting citizens from harmful substances, has extended the list to cover 100 “unsafe” materials.

While they recommend that some must be declared on packaging or the amount used in a perfume be restricted, they want some - including the tree moss used in Chanel No 5 to help give it its distinctive smell - banned entirely.

And while these are only guidelines and not law, it is likely that perfume manufacturers will feel pressure to comply. The industry watchdog, the International Fragrance Association, is taking it so seriously it has decided to conduct further research into the potential skin allergens on the back of the recommendations.

This doesn’t affect only Chanel; a host of other well-loved perfumes - from Miss Dior to Guerlain’s Shalimar and Angel by Thierry Mugler - could be caught up, too.

For the new list calls for restrictions of many commonly used ingredients such as citral, found in lemon and tangerine oils, and coumarine, which comes from the spicy South American tonka bean - all naturally sourced ingredients which have been used for decades.

It is even feared that jasmine and rose - some of the most common ingredients in the world’s favourite scents - could be put on future lists.

Francis Pickthall, director of international fragrance house CPL Aromas, argues that ingredients being banned or restricted is nothing new to the industry, and that perfumers are expert at phasing out problem materials while finding alternatives.

But Chanel spokeswoman Francoise Montenay declared: “It would be the end of beautiful perfumes if we could not use these ingredients.” - Daily Mail