Combating Questions of Nanotechnology Safety

Here we go again. Have you heard about the folks in Australia all hot and bothered about hidden nanotechnology in their sunscreens? This is one of those scare stories that appears on the horizon as dependably as sunrise -- and will set just as certainly.

Let me start at with a little background. You know the iconic image of a lifeguard with a white smear of sunscreen on his nose? The stuff that makes sunscreen white is zinc oxide, highly effective, but not particularly attractive. One of the earliest applications of nanotechnology was making the zinc oxide particles smaller -- nano-sized -- so they could do their job without the telltale pasty coating. These products have been around for about a decade without issue.

That track record didn’t seem to satisfy some zealots in Australia. So they began requiring manufacturers to include a statement on the label of nano-enhanced sunscreens. Guess what. Some self-serving marketers decided they could profit from a little fear-mongering and started labeling their products as “nanoparticle free.”

I could write a whole column on that bit of marketing flim-flam, but the story takes an even more bizarre turn. Some dogmatic nano-hunters did their own testing using their own methodology. They were looking not only for nanoparticles but also for “agglomerates and aggregates of nanoparticles,” that is, non-nanoscale materials made up of nanoparticles.

The Australian nanotech sunscreen uproar has been billed as an exposé, but it’s really just a calculated gotcha maneuver. These aggregates have never been shown to break down into individual nanoparticles, unless exposed to tremendous forces. Never. Not one time.