Although times are a’changing, tanned skin still symbolises health, activity, and dynamism – despite warnings from our Australian of the year – pioneering melanoma researchers Professor Richard Scolyer and Professor Georgina Long – people still sit in the sun to tan, relying on sunscreen for protection.
But how good is your sunscreen? Are you protected from skin cancer?
Sunscreens have been around for over 80+ years with the current SPF or sun protection factor being introduced in the 1970’s. It is estimated that the market is worth 14 billion dollars globally and is set to increase on the back of global warming between 2020-2030.
The sun emits three distinct type of rays UVA, UVB, UVC. UVC rays are unable to penetrate the ozone layer, so they have no impact on our skin. UVB can penetrate the basal layers of the epidermis and can damage the DNA resulting in the reddening or burning of the skin.
UVA rays are nasty. They typically range from 320-400 nanometers of solar radiation and penetrate deeper into the skin to cause damage to the DNA through free radicals. They are the rays that are responsible for causing skin cancer. They do not burn the skin; You can’t see the damage that they cause.
Australia has the worst instance of skin cancer in the world primarily due to our love of the outdoor lifestyle. But our sunlight yields a darkness that is invisible to the eye. Once the skin is damaged it no longer protects it from the sun in the same way
There has never been a more important time to ensure that you are protected from the harmful sun’s rays.
How is sunscreen tested?
For a sunscreen to have an SPF 50+ rating the sunscreen must provide 33% protection against UVA rays and 66% against UVB rays. They test is usually conducted on people who have differing skin types.
Sunscreen is applied to the skin at a rate of 2 grams per square centimeter and then a measurement is taken identifying the perceptible reddening of the skin or MED (Minimal Erythema Dose) up to 24 hours after the exposure to the UV rays.
It is interesting to note that your 50+ sunscreen only offer 16.5% protection against the harmful UV rays and to get this level of protection you would need to apply it at a rate of 2 grams per square centimeter.
For testing UVA rays manufacturers use an ISO test conducted in a test tube. UVB rays are tested on people. For a water-resistant claim, the same test is conducted however subjects are placed in a spa anywhere from 40 minutes to 4 hours and then are tested.
How Does it Work?
Sunscreen has two primary methods of protecting your skin. The first being chemical protection or organic protection which uses ingredients like octylmethoxycinnamate to absorb UV light. Do not be fooled by the classification of Organic as whenever you see the letters “eth” it implies a synthetic component of manufacture.
The second classification is regarded as physical protection or inorganic, using ingredients to reflect light such as Zinc Oxide or titanium oxide. Interestingly these ingredients are used in Natural or Organic sunscreen products but are not at all natural or organic. They go through synthetic processing, but regulators regard them as natural.
To formulate a sunscreen usually two ingredients are used in synergy – one that has efficacy data to inhibit exposure of UVB rays, the other, UVA.
In Australia a product that has a SPF of 15 or lower or the SPF claim is the secondary function of the product, it is classed as a cosmetic. But if the SPF is over 15 or the SPF function is primary, then they are classed as a drug and have for more legislative requirements from the manufacturer to be compliant.
How Natural is Sunscreen?
Most consumers want a sustainable product with no impact on the environment. However, using a completely natural or organic ingredient can significantly impact the performance of a product.
By definition most sunscreen products utilise synthetic ingredients or natural ingredients that have gone through synthetic processing.
Is Sunscreen Damaging Our Reefs?
It is true that there are some significant concerns about the impact of certain sunscreens on marine organisms. This concern comes from the active ingredients used in sunscreen which have been identified in marine eco systems.
A report conducted in 2022 from (the) nationalacademies.org web page identifies that more research is needed to identify the impact of the ingredients used. However, there are some countries around the world that have identified certain ingredients: -benzophenone-3, ethylhexyl methoxycinnamate, octocrylene, methylbenzylidene camphor as potentially impacting marine ecosystems.
Some companies are claiming that they do not have these potentially impactive ingredients in their products, so they are safe for marine environments. This is not completely correct. These companies are still subject to marine toxicology tests and water resistance testing.
For a sunscreen to be deemed safe for our reefs it must be water resistant for 4 hours with both In Vitro and In Vivo efficacy data to substantiate the claims made by the manufacturer. It must have a marine toxicity test conducted by the relevant authority including micro algae Cell division, Sea Urchin Larval development, and Fish Larvae development.
What Are Nano Particles? Are They Harmful?
The primary ingredients in a sunscreen that protect us from UVA/UVB rays by either reflecting or adsorbing light are called zinc oxide and titanium dioxide which have been used for over 30 years. The only issue with these ingredients is that they mass together and causing white ghosting on the skin. To counteract this issue, they reduce the particle size to roughly 1-100 microns which removes the ghosting when applied to the skin and for the most part is the most effective protective aspect against the harmful UVA/UVB rays.
When these ingredients are ground down to this size, they produce chemical properties that react to light and are catalysts in the production of reactive oxygen species (ROS). This means they have the ability to turn on and turn off biological markers in animals, including dangerous genetic mutations.
To stop this manufacturers’ coat the nano particles with aluminum hydroxide which has been highly effective in reducing the ROS. But when these particles come into contact with chlorine (such as sea water) these nanoparticles in the presence of sunlight can produce free radicals which may lead to cancer.
It has also been discussed that certain types of nanoparticles used in sunscreens are also used in some exterior paints which has proven to be the direct cause of rapid deterioration of painted surfaces on steel roofing.
More study is required to make an absolute determination on the potential of nano particles leading to further health concerns.
The Best Way To Be Protected From The Sun
Sunscreens do work, however to get the advertised performance from these products you need to apply them extremely thickly (2 grams of product per square centimeter) though I have never seen anyone using a sunscreen this diligently.
They do provide significant benefit in protecting us against the harmful effects of the sun but do not offer the level of safety that we think. Many consumers assume applying a 50+ sunscreen makes them safe from sun damage.
But if you’re out in the sun best advice is to use an SPF 50+ “reef safe” sunscreen and apply it every two hours plus wear a hat and a T-shirt. You can buy full cover protective swimsuits for little children but don’t forget a hat!
We have the worst instance of skin cancer in the world. It can go undiagnosed for years often until it is too late. While there a brilliant skin cancer specialists and surgeons, the safest prescription is to slather on the best sunscreen regularly during the day and cover up.