The products, which include anti-wrinkle creams such as Revitalift, are said to be absorbed deeper into the skin than more traditional treatments because of the far smaller size of their particles.

However, the cosmetic use of nanotechnology, originally employed in man-made fibres and pharmaceuticals, has led to calls from both the Royal Society and the Food and Drug Administration (FDA) in America for a comprehensive programme of research.

They aim to discover what effect the minute particles may have if they enter cells in the human body or leach into the bloodstream.

The FDA will also assess whether a trialling and licensing system should be introduced for cosmetics similar to that used for pharmaceuticals.

“Very little is known about the interaction of nano-scale particles and the skin,” said the FDA. “We need urgent research to assess the safety and we are hoping to get some answers soon.”

The Royal Society, Britain’s most prestigious scientific body, said: “We don’t know whether these particles are taken down through the skin and what the long-term effects might be in the bloodstream.”

Nanotechnology — which has been derided by the Prince of Wales as “grey goo” — has provoked similar fears to those sparked by genetic modification, although no harmful effects have been proved.

The cosmetics market is growing at about 10% a year and companies believe that nanotechnology will help to create a new generation of products. Within the next few years they hope that it may provide methods to prevent the greying of hair and even baldness.

L’Oréal, the world’s largest cosmetics company, is devoting much of its £350m research budget to nanotechnology, which it believes offers great potential for slowing the effect of age on the skin.

Revitalift, described by L’Oréal as containing “nanosomes of Pro-Retinol A”, claims to offer an “immediate lifting effect”.

Conventional skincare products form a barrier to prevent moisture loss. The miniaturised particles, by contrast, and intended to work their way through the skin’s outer layers and boost production of new cells so the skin remains soft, plump and free of wrinkles, even in middle age.

Nano particles also broaden the range of chemicals that can be used in cosmetics. They are used to coat the surfaces of microscopic packages of vitamins, growth promoters and other substances that, if used in their raw form, would cause irritation. When modified, they can be taken into the underlying layers of the skin.

Wendy Lewis, a skincare consultant and author of the book Beauty Secrets, said the use of nano particles was “hot technology that has lots of intriguing applications”.

She added: “We are seeing a generation of baby boomers who don’t want to grow old or look old and, if things work, they are prepared to spend the money to pay for them.”

According to Lewis, Botox, the injectable anti-wrinkle agent, had increased the pressure on cosmetics companies to produce a skin cream with a similar effect. “Botox has proved women will pay a lot for something that works and the race is on to find a more convenient way of getting the same effect from a cream,” she said.

L’Oréal declined to say how many of its 3,000 researchers worldwide are working on nano particles, nor would it discuss where the technology may lead. But the company has patented the use of dozens of different “nanosome” particles 800 times smaller than a human hair as delivery systems for nutrients.

“We think this is an important development and we want to stay at the leading edge of offering our customers better and better products,” said a spokesman.

As well as Revitalift Double Lifting, which delivers vitamin C into skin, it has launched new forms of Vichy Reti C and Biotherm Age Fitness Nuit, both facial moisturisers.

Other cosmetics houses are moving ahead with their own versions of the technology. Dior has invented the “liposome” to perform the same function as L’Oréal’s nanosomes; an Australian company has just launched ZO1, which uses miniaturised zinc oxide particles as sunscreen. Estée Lauder and Johnson & Johnson are also developing products based on nanotechnology.

The Cosmetic Toiletry and Perfumery Association said this weekend that nano particles were not yet widely used in cosmetics, but all products were thoroughly tested before their launch: “With millions of consumers using cosmetic products as part of their daily routines, it is essential for our industry to ensure products are thoroughly assessed for safety.”

Explore UK News

• Science News

• Crime News

• Education News

• Health News

• Scotland News

Times Recommends

• Savers left in limbo as Icesave freezes deposits
• Kennel Club changes breeding rules
• Passengers triple risk of fatal crashes