Articles against nanoparticles in sunscreen

It’s that time of year for us Aussies where the budget is stretched, the sun is hot and commercial sunscreens are no longer cutting it – too expensive, itchy, heavy, fragrance issues, stingy, full of ‘nasties’ and the list goes on.

I have had numerous conversations with people wanting to make their own and usually this involves an attempt to blend either Titanium Dioxide or Zinc Oxide into a base.

My advice is always the same. Don’t try it, it doesn’t work……..

One of the things that home-made sunscreen people are keen to avoid are nano particles.

Nanoparticles sound man-made, potentially dangerous, different, weird even.

The organic standards that I am aware of don’t allow them – well, not man-made ones anyway.

The scientific jury is still out on some of the finer details of the long-term health and environmental implications of using nano particles in cosmetics.

Which begs the question, why do we use them?

Well first of all let’s get a little more clarity on the term nano particles. In terms of the cosmetics industry we have a general understanding that a nano particles is something that is sized between 1-100nm.

You could fit around 88, 000 1 nm large things across the width of a human hair.

Or 880 100nm large things in the same space.

But it isn’t just about size. There are some other bits of data that matter when it comes to defining nano particles. Here is the EU official definition:

‘an insoluble or biopersistant and intentionally manufactured material with one or more external dimensions, or an internal structure, on the scale from 1 to 100 nm’.

The part about the particles having to be insoluble is very important. Insoluble in what? This is an applied measure in as much as solubility must be relevant to the ingredients application and fate – water, oils and other substances that it will come into contact with along its journey intended or otherwise.

The part about its biopersistance is also highly relevant - will the nano particles remain in the body, accumulate, become toxic etc? Will they make their way up through the food chain? Will they mutate and turn us all into zombies?

Intentionally manufactured is also worth noting as nano particles do exist in nature. This isn’t all science fictioning!

Anyway, as you can sort of see from the above, defining a nano particle isn’t actually as easy as shouting ‘hey, there you are!’ and noting it in your nano spotting journal. It is actually quite tricky.

So with that in mind people like the guys at Australian Certified Organic have decided to stay well away and have gone with a minimum 300nm size restriction on their permitted ingredients. Now while this means that products certified by the ACO will contain no nano particles it doesn’t necessarily mean they will be safe, especially when it comes to sunscreens.

The Zinc Oxide and Titanium Dioxide that are really good at protecting us from the sun have very particular chemical and physical properties that make them so efficient and are referred to as ‘attenuation grade’ materials.