Sunscreen Technology
By: Michelle Kodis

Gone are the days of looking like you’ve just seen a ghost—or perhaps turned into one—after the application of metal oxide-based sunscreens that contain zinc and titanium, both excellent UV blockers. The credit goes to scientists working in the emerging field of nanotechnology, which, according to the National Nanotechnology Initiative, focuses on “the control of matter at dimensions of roughly 1 to 100 nanometers, where unique phenomena enable novel applications.” In other words: The engineering of particles at the sub-molecular level.

A nanometer measures a mere one-billionth of a meter and yet, despite its minuscule size, its influence and reach is potentially significant, notably in the consumer products industry. The Environmental Protection Agency has a list of items that contain nanomaterials, but sunscreens and anti-aging potions (think: liposomes) are currently the most prevalent.

Sunscreen that goes on clear instead of pasty seems like a good thing, but a general feeling of wariness clouds nanotechnology, and consumer advocacy organizations and experts have expressed concerns about the potential dangers of a technology that hasn’t yet stood the test of time. Questions remain as to what nanoparticles do once they’re inside the body. It is known that they can move through tissues and cell membranes more easily than larger particles—for example, they are able to pass between the blood and the lungs and breach the blood-brain barrier. Studies also indicate they can penetrate the placenta, and additional evidence suggests that metal oxide particles can cause free-radical production when introduced into living cells, in turn damaging the cell’s DNA. If you’re concerned, avoid metal oxides designed to become transparent once they touch the skin. Manufacturers are not required to list them, but if you see “Z-COTE” and “ZinClear” listed in the ingredients, that’s a sign of nanotechnology in action.

To learn more about nano products, visit the Project on Emerging Nanotechnologies’ (PEN) website at