At last, I have found what may be the perfect sunscreen. Grahams Natural Alternatives SunClear. It ticks all the boxes: it's zinc oxide based so is a physical barrier, not a chemical one; it's completely clear on the skin so it's invisible; it's nano-particle free so it doesn't mutate you in the slightest; its base is natural plant oils making it reef friendly and it's made in Australia by a family owned business.
Having a little bubba makes you think about what goes into sunscreens, as most sunscreens are a cocktail of chemicals. Most protect the skin by forming a chemical barrier, but zinc oxide sunscreens (think white noses) physically block UVA and UVB rays. Previously zinc based sunscreens were thick and white but recent developments have made it possible to reduce the particle size to a point that the sunscreen is invisible.
I'm sure you've heard of nanotechnology. Nanoparticles are an example of this, and some sunscreens use zinc in this form. However there is widespread concern about potential health risks of this type of product as the nanoparticles are so small they can penetrate the skin and once inside the body could cause problems. The following is from a Friends of the Earth Nanoparticle Fact Sheet:
Nanoparticles in sunscreens could cause skin damage
Scientific studies have shown that nanoparticles of titanium dioxide and zinc oxide commonly used in sunscreens can produce free radicals, damage DNA and cause cell toxicity, especially when exposed to UV light. The concern is that rather than offering us sun protection, nanoparticles could actually result in serious skin damage. In a serious early warning sign, Australian researchers have found that roofs which have come into contact with sunscreens containing nanoparticles age 100 times more rapidly than surrounding areas of roof that have not come into contact with sunscreens containing nanoparticles. Whether or not sunscreens containing nanoparticles could do the same thing to our skins is unknown. This depends on whether or not nanoparticles in sunscreens can penetrate the dead outer skin layers and reach the living cells beneath – something no-one knows.
The upshot is that if you are looking to buy one of the new breed of sunscreens that offer invisible physical protection, you need to know if it is nano-free. Our regulations don't require companies to label their products with this information however, so you need to do your own research. A good starting point is here: http://nano.foe.org.au/node/286
The Grahams product is nano free. The market leader is Invisble Zinc. This is now also nano-free but only since they bowed to public backlash against nano particles. They launched (with Megan Gale) a few years ago trumpeting the amazing nano breakthrough - but it's no longer cool to wear a nano sunscreen.