Since they are quite easy to make, your face mask may very well carry EGF-impregnated nanofibres. If so, these are so tiny in size they could slip through the skin and into the bloodstream. From there, they could pass through the blood-brain barrier and get into the brain itself. (That barrier is a one-cell-thick filter that otherwise protects the brain from bugs and drugs, which are much larger than nanoscale molecules.)

In the body, nanoscale materials tend to behave oddly. Their behaviour can be quite unpredictable. A 2007 United States government report noted that because they have 'altered magnetic properties and altered electrical...chemical or biological activity...nanoscale materials may pose different safety issues' than conventional materials.

By itself, carbon is inert, for instance. However, in lab mice, carbon nanotubules have been found to cause mesothelioma, a cancer of the lung linings - just as asbestos fibres did in miners of old.

Many consumer products nowadays do carry nanoscale ingredients, whether they are so identified on the packaging or not. There is currently no law anywhere that requires their disclosure or proof of their efficacy and safety.

Last year, a Princeton study documented hundreds of cosmetics and personal care products - many of which come with promises of helping fight skin ageing - whose packaging claimed nanoscale ingredients.

All in all, unnecessarily flogging EGF receptors with EGF sprinkled on nanoscale biostructures seems particularly foolhardy. On the whole, it would be best to just junk such face masks.

This article was first published in The Straits Times.