With so many sunscreens on the market, it’s hard to know which one to choose. We’ve broken down the difference between sunscreen ingredients so that your next sunscreen shopping trip is a little easier.
Sunscreens form the most essential step in preventative skincare. Active ingredients like retinol, peptides or exfoliating acids can repair and rebuild your skin, but without sunscreen, UV damage simply undoes all the hard work your anti-aging skincare has achieved. It’s easy to say that everyone should wear sunscreen, but finding the right sunscreen isn’t quite as simple.
What is sunscreen?
Sunscreens are products that combine several ingredients that prevent the sun’s radiation from reaching the skin.
The chief types of radiation that cause premature aging and skin cancer are UVA and UVB.
UVB is the main cause of sunburn, while UVA rays penetrate more deeply and cause wrinkling, sagging and pigmentation (such as sun-spots).
Different sunscreen ingredients and different formulations vary in their ability to protect against UVA and UVB rays.
What is SPF?
SPF stands for Sun Protection Factor, and measures a sunscreen’s ability to prevent UVB from damaging the skin. If it takes 20 minutes for your unprotected skin to start turning red, then applying a product with an SPF 15 means that you can stay out in the sun 15 times longer. 20 minutes multiplied by 15 is 300 minutes, or 5 hours.
SPF ratings also vary by their ability to block percentages of incoming UVB rays:
- SPF 15 filters out approximate 93% of UVB rays
- SPF 30 filters out approximately 97% of UVB rays
- SPF 50 filters out approximately 98% of UVB rays
These figures have been calculated in laboratories and studies, which are very different to real-world circumstances. Skin often gets touched or rubbed by clothes, towels, hands or other environmental factors, which means that you should not expect a sunscreen to effectively protect you for more than 2 hours without reapplying.
Importantly, SPF only measures UVB. UVA, the rays that cause wrinkles and signs of aging, are not part of any SPF calculation.
How do I deal with UVA rays?
Sunscreen manufactured and labelled in Europe and Asia use ratings such as PPD and PA+ to measure a sunscreen’s ability to protect against UVA. Like SPF, the PPD or PA+ rating is calculated on how long it takes for skin to tan.
Australia does not use the PPD or PA+ scale. Rather, all sunscreens over SPF 4 must be ‘broad spectrum’, which means that they must block both UVA and UVB rays.
What is in sunscreen?
There are two major types of sunscreen ingredients: organic (chemical filters) and inorganic (metal oxides).
Chemical filters are chemicals that absorb UV radiation and stop it from penetrating your skin. Metal oxides are small particles of zinc oxide or titanium oxide that reflect and scatter UV radiation.
Sunscreens can use only chemical filters, only inorganic filters, or a mixture of both.
In Australia, chemical sunscreens include:
- butyl methoxydibenzoylmethane, also known as avobenzone (UVA)
- Ecamsule, also called Meroxyl SX (UVA)
- Octocrylene (UVB)
- Homosalate (UVB)
- Octyl salicylate or octisalate (UVB)
- Octyl methoxycinnamate or ethylhexyl methoxycinnamate (UVB)
- 4-methylbenzylidene camphor (UVB)
- Bemotrizinol, also called Tinosob S (UVA and UVB)
- Methylene bis-benzotriazolyl tetramethylbutylphenol, also called Tinosorb M (UVA and UVB)
- Oxybenzone and dioxybenzone (UVA and UVB)
Inorganic filters/metal oxides:
- Zinc oxide (UVA and UVB)
- Titanium dioxide (UVA and UVB). Titanium dioxide does not protect against UVA as well as zinc oxide does
When looking for a sunscreen, check to make sure that the ingredients label mentions filters that block UVB and UVA. If it is made in Australia, it will be regulated and should be broad spectrum.
Are you using enough sunscreen?
A sunscreen with an SPF rating of 50+ becomes much lower in real life when applied thinly.
That’s because SPF ratings are determined when sunscreens are applied at a rate of 2mg per square centimetre of skin, which means about 1 teaspoon for the average adult’s head and neck.
One teaspoon is actually a lot of product, so pull out a measuring teaspoon from your kitchen cupboard to see how much sunscreen you actually need to get the advertised protection!
It is easier to apply the required amount when using sunscreens that are lightweight and sink into the skin. Our Super Moisture SPF 50+ is formulated so that it does not feel too heavy and sticky when applied liberally to the face. Fountain’s Day Defense SPF 15 also offers comfortable, everyday sun protection.