We all know that it’s majorly important to protect our skin with an SPF (if we want to avoid sunburn, skin cancers, and stay wrinkle- and pigmentation-free for as long as possible that is!), but just because we know we have to do it, doesn’t mean we understand how SPFs work.
I don’t know about you, but I for one have always wanted to know things like how SPF 15 differs from SPF 30, and what ‘broad-spectrum’ actually means, so we got Olay Scientist, David Khoo, in for a chat to answer all our burning questions…
Bh: How does SPF actually work? And how exactly does SPF 15 differ from SPF 30?
DK: SPF is the ratio of how much UV is required to produce a perceptible redness on skin protected by sunscreen, as compared to unprotected skin. So in theory, SPF 15 should increase the time it takes before your skin turns red by 15 times, and SPF 30 by thirty times. For example, if it ordinarily takes 10 minutes for your skin to turn red, SPF 15 would extend that to 150 minutes. However, it’s important to realise that SPF doesn’t represent a specific length of time. Rather, it represents a variable duration – the time it takes for skin to turn pink – which depends on individual skin characteristics and intensity of exposure.
An SPF 15 product blocks 93.3% of burning UV rays, while an SPF30 product blocks 96.7% of burning UV rays. Thus, both products provide relatively similar UV protection, but the SPF 15 product will likely have better skin feel, and hence may be more likely to be used more often and at a higher dose per use. Poorly formulated product (those that feel heavy, thick or greasy) is likely a primary reason sunscreen is under-applied.
Bh: What’s the difference between SPF+ as opposed to those that don’t have a ‘plus’?
DK: The plus sign indicates that the sun protection level is higher than the given numeric level. For example, SPF 15+ means that the sun protection level is higher than 15. You also often see SPF 30+, which means the sun protection level could be between 31 and 60, but 30+ is the maximum that can be claimed under Australia’s regulations.
Bh: What does the term, ‘broad-spectrum’ really mean? How are broad-spectrum sunscreens different to those that aren’t labelled as such?
DK: Broad-spectrum sunscreens indicate protection against both UVB and UVA rays. Sunscreens are evaluated and classified according to their ability to block mainly UVB rays. For a sunscreen to provide broad-spectrum UVA/UVB protection it generally requires a combination of sunscreen actives within the ingredients.
Bh: Is it true that you can spend longer in the sun before reapplying if you’re using a sunscreen with a higher SPF?
DK: As mentioned before, SPF doesn’t refer to a specific length of time. Because sunscreens can break down or wash off over a period of time, to be safe it’s best to use, at minimum, a broad-spectrum SPF 15 sunscreen, and reapply every 2 hours.
Bh: Why can you get SPF 50 and above overseas, but not in Australia?
DK: Australian standards for sunscreens do not allow, at this point, an SPF claim above 30. However, revision is underway and it looks likely that an SPF claim above 30 will soon be allowed.
Bh: Should you use a specific face sunscreen depending on your skin type/skin concerns?
DK: Some products are dedicated sunscreens, while others are moisturisers that improve overall skin health and also provide sun protection.
The Olay Complete UV Protection Moisture Cream 15 is one example of the latter. It provides up to 24-hour hydration and makes dry sensitive skin less sensitive. It helps promote and maintain healthy looking skin, and calms and relieves dry sensitive skin with extracts of aloe and chamomile. Last but not least, it protects with SPF 15 and antioxidant vitamin E to help prevent premature skin damage.
