Chanel No5, which has been on the market for 93 years, is the world's bestselling perfume.
It is said that when Gabrielle "Coco" Chanel, founder of the fashion house, sprayed the scent in a Paris restaurant in 1921, women stopped to ask her what it was.
Chanel and Dior have been working on altered versions stripped of the molecules atranol and chloroatranol, regarded as potential allergens by the EU.
"Adapting is a challenge but it is precisely the talent of our 'nose' to be able to preserve the qualities and olfactive identity of our perfumes, while also taking into account new regulatory constraints," a spokesman for Chanel said.
The rules will also require products to be fully labelled and include allergy warnings in the same way as medication. In 2012, an advisory report recommended limiting the use of 12 ingredients including citral, found in lemon and tangerine oils; coumarin, found in tropical tonka beans; and eugenol, found in rose oil.
However, just three, citral, atranol and chloroatranol, are now likely to be banned, with an investigation taking place into the remaining nine to see if small amounts could be tolerated.
The perfume industry has complained that even small changes could radically affect scents and sales.
"If we ban citral from perfumes, of which certain elements are allergens, we should ban orange juice. It is absurd," said Frederic Malle, who founded the French luxury perfume company Editions de Parfums Frederic Malle.
