Is nanotech innovation moving too fast in the cosmetics field?

Soap, Perfumery & Cosmetics Magazine, a trade journal for cosmetics formulators, posits the theory that the cosmetics sector is pressing ahead with nanotechnology innovation despite consumer fears.

While many of the claimed benefits of nanotechnology remain uncertain, the cosmetics industry is at the vanguard of developments. There seem to be real advances that nanotechnology can offer for particular products, such as sunscreen and anti-ageing creams. On the other hand, for much of the public ‘nano’ remains a suspicious word that is linked to deep-rooted fears connected with genetically modified food controversies.

Nanoparticles are already being used in the manufacture of transparent sunscreens. Those of titanium dioxide in sunscreens, for example, have the same chemical composition as the larger white titanium dioxide particles used in conventional products for decades, but nanoscale titanium dioxide and zinc oxide is transparent.

“When you get below 100nm in size, you end up with a transparent form of zinc oxide,” says Ken King, ceo for Micronisers, a Melbourne, Australia-based company that produces nano sunscreens. “You get the same degree of UVB and UVA protection and that opens up potential for skin protection through other products, such as aftershave or shampoo. The reality is that your risk from skin cancer doesn’t just involve going to the beach – it runs from 9am to 5pm. Most people wouldn’t go to work with white zinc oxide on their nose and lips, but now they might be able to have adequate protection for the whole day.”

Proponents argue that nano sunscreens are intrinsically safer than organic UV absorbers and that particle size can be selected to potentially limit potential skin absorption. A technique which puts UV-blocking nanoparticles into sunscreen has made it possible to combine extremely effective protection with a clear, natural finish. This technology, developed by Oxonica, a spin-off company at the University of Oxford’s Begbroke Science Park, may also have applications in the removal of certain skin tumours. Professor Peter Dobson, academic director of Oxonica, argues that the nanosunscreen his company produces is safer than traditional sunscreens.

“The thinking at the time was that we should go to smaller and smaller particles so that people weren’t rubbing white stuff all over them,” says Dobson. “They wanted to have a natural skin colour, and by going to nanoparticles you maintain an optical transparency and yet you can block the UV.”

The challenge for scientists has been that small particles of zinc oxide and titanium dioxide also have a very high surface area for a given weight, and these materials are photoactive. This means they can catalyse photochemical reactions in the sun and possibly cause damage. Dobson suggested treating the particles as semiconductor particles and doping them in order to shift all the energy levels and avoiding the damage that a normal photocatalyst causes. Doping involves adding tiny quantities of manganese to the titanium dioxide so that it goes from being a semiconductor that conducts electrons to a semiconductor that conducts using holes rather than electrons. This shifts all the energy levels enough so that in the presence of sunlight there is no risk of producing damaging free radicals which the normal sunscreen material would cause.

Legal investigation

However, there have been concerns raised by EU officials about the absorption of ultra fine nano TiO2 (shown to be absorbed into the brain cells of rats) and potential for tissue effects from free radicals.

Last year, the European Commission’s Scientific Committee on Emerging and Newly Identified Health Risks (SCENIHR) described the area as “new and rapidly developing” and reported that “special attention” should be given to the determination of safe dosages because this was likely to differ in substances working at the nano level compared with larger products.

The committee was sufficiently concerned about the potential impact of nanoparticles that it called for “due consideration be given to the possibilities now emerging that translocation of nanoparticles away from the portal of entry may occur in humans and other species, and that the passage of nanoparticles across membranes could give rise to adverse effects, for example within the cardiovascular system or following passage across the blood/brain barrier.”

Sunscreens are seen as one of the key routes, in this case the dermal route, by which nanoparticles can potentially enter the body, along with inhalation, oral and medicinal use. The typical pore space in healthy skin is 25-30nm, but some sunscreen products now include nanotitanium with particle sizes of 5nm.

The cosmetics industry is putting some thought into just how to deal with the question of public and regulatory wariness, according to Professor Lynn Frewer of the Marketing and Consumer Behaviour Group at the University of Wageningen in the Netherlands. Frewer believes the cosmetics industry is approaching the introduction of nanotechnology more cautiously than the food industry and is wary of the experience of those companies that sought to introduce genetically modified food products.

“Cosmetics companies are a lot closer to consumers than the likes of Monsanto were. They are sensitive to consumer trends and they are more visible on the supermarket shelf,” she says. “They are treating this very gently.”

Cosmetic specialties

Face cream is likely to be a key area for nano products, according to Frewer. “The new generation of face creams and anti-ageing creams do have the capacity of genuine cosmetic enhancement, at least temporarily,” she says. “This is because they can get into the subcutaneous part of the skin, but if they can do that they can go even further. It’s a question of risk perception and benefit perception. You are going to get some people that are prepared to accept the risks of nanoparticles in return for the benefits.”

Frewer believes the regulatory framework will need to be tightened. However, she feels the industry has less chance of being subjected to major public opposition towards nano products than the food industry. “There will be a lesser degree of opposition unless there is a regulatory response about a particular nanoparticle,” she says. “People think in a different way about cosmetics than they do about food. Most women and men are prepared to accept technology into personal care where they wouldn’t in food. It’s partly because with cosmetics you are beginning to slip into association with the medical sector. But we are beginning to see some public hostility to nanotechnology in food and that could be a concern if the association is with nanotechnology itself rather than with nanotechnology in food.”

King also feels the industry needs to tread carefully. “The best approach is to have an informed consumer,” he says. “There is a strong case for arguing that further studies should be conducted to give assurance to the public. But it must be presented in the right way and must not be construed as a marketing effort by multinationals.”

CEFIC, the Brussels-based organisation representing the European chemical industry, also acknowledges that the public must be paid far more than lip service when it comes to discussions about safety and regulation. “We are taking it very seriously and must not make the same mistakes as have been made in other areas of technology,” says Gernot Klotz, executive director for CEFIC Research & Innovation. “Advocacy is not enough by itself.”

CEFIC has just launched and funded a long-range research initiative, calling on the scientific community to submit current papers and material that discuss the risks of nano products. “In the next two years we will learn where the gaps are and where we can be reasonably certain,” he says.