It is crucial for consumers to understand the importance of sunscreens and understand their labels so they can incorporate them and choose the best and most protective option for their skin care needs. But it is no surprise that reading SPF labels, their numbers, and PA leave consumers puzzled. It’s a lot to learn and a lot to unpack!
Sunscreen is a vital component to a sun protection plan to decrease your risk of skin cancers and precancers. According to the Skin Cancer Foundation, using just an SPF of 15 on a regular, consistent basis, you can reduce the risk of squamous cell carcinoma (SCC) from developing by 40%! The risk of developing melanoma also decreases by a stunning 50%!
Sunscreen does not only provide skin cancer protection measures, but also provides cosmetic value. It is not uncommon for skin care enthusiasts to incorporate anti-aging products into their routines. But it doesn’t matter the serums or ampoules used, sun protection is the most important and preventative asset to combat wrinkles, sagging, and sun spots.
And get this, not only does sunscreen prevent signs of aging, but it can also repair signs of aging! In a 2016 study conducted by dermatologists, a group of participants applied a moisturizer with SPF 30 (with no use of other anti-aging products) for a year. After following these participants, they saw visible improvements in texture, tone, and fine lines. 52% of participants saw improvements in the appearance of their sun spots, 40% saw skin texture improvement, and 41% of participants had clearer skin with a year of use! How could sunscreen provide such drastic improvements? Though still not clear, dermatologists suggest that because sunscreen provides skin protection, the skin’s natural innate regenerative properties are able to work better. Our skin turns over every 28 days. By providing our skin with defences against daily accumulated damage from the sun, we allow our skin to heal previous damage on its own instead of having to focus its resources on defending and repairing itself at all times from everyday UV exposure!
Now, in order to further understand what the labels on sunscreen means, UVA and UVB rays need to be defined.
UVB Rays reach the skin’s outer layers (epidermis) where the most common skin cancers form. These types of cancers are usually triggered by sun-accumulated damage over the years. Melanoma, however, is theorized to be caused by intense and short, brief exposures.
UVA Rays are longer, thus they can penetrate deeper into your skin to reach the dermal layer, where it damages collagen and skin elasticity. In the skin’s dermal layer, lies the cells that trigger the skin to darken. Thus, making UVA rays responsible for the tanning look. Tanning is a popular trend, but most people don’t realize that tanning is actually a sign of DNA damage. Tanning is a process that your skin starts in order to try to prevent any further damage. This process can lead to cell mutations and skin cancer.
Thus, a quality sunscreen is one that protects the skin from both UVB and UVA rays. This is where SPF and PA come into the picture.
SPF stands for Sun Protection Factor. It is the ability to protect the skin from the sun’s ultraviolet B (UVB) rays. This is measured by the time it would take for a person to start getting red without wearing sunscreen. This is where the SPF number comes in.
It takes about 10-20 minutes for your skin to start burning without protection. An SPF number can demonstrate potentially how long it could take before you start burning. For example, an SPF 15 (if used exactly as directed) can prevent skin burning about 15 times longer than not wearing sun protection. So an SPF 15 can protect you for about 150-300 minutes (2.5 hours -5hours). However, this does not mean you are protected for all 5 hours, you must reapply every 2-4 hours, considering that SPF can be wiped off, rubbed off, sweated off, or washed off. And remember, SPF measures protection from the amount of UVB exposure, and does not determine duration of exposure. Meaning, wearing sunscreen alone does not mean one could stay out longer in the sun without damaging consequences, regardless of SPF protection.
So does this mean an SPF 30 is twice as better as SPF 15? Err, not exactly. Just because the number 30 is double than 15, it does not necessarily mean it is twice as good in terms of how much UV blocking one receives. It is generally twice as better in terms of how long it protects your skin from turning red (150 minutes versus 300 minutes), but it is not twice as better when observing how many UV rays get absorbed in the skin with an SPF 15 versus an SPF 30.
Unfortunately, the SPF Scale is not linear:
This means that an SPF of 30 only gives you 4% more protection from UVB rays than SPF 15. In other words, for every 100 photons directed at human skin, an SPF 15 allows 7 out of 100 to be absorbed. An spf 30 allows 3 out of 100 photons to be absorbed into the skin. To summarize, while an SPF of 30 can double the length it takes to make your skin red as compared to SPF 15, an SPF 30 only provides a difference of 4% from UVB rays. However, it is crucial to note that despite SPF 30 theoretically protecting the skin for a longer period, an SPF 30 must still be applied on the skin as often as an SPF 15. This is because regardless of sunscreen used, the protection offered can easily be worn off by sweating, rubbing, washing, environmental reasons, and several other factors.
A good quality sunscreen will be listed as “Broad Spectrum” or contain PA+++ ratings on sunscreen bottles. PA defines the amount of protection from UVA rays. PA stands for Protection Grade of UVA ray. These ratings work together with PPD, or “Persistent Pigment Darkening”. PPD is how long it takes for your skin to tan. If there is a PPD of 2, it means it takes twice as long for your skin to tan as compared to not wearing any PA protection. So, the more plus signs on a PA rating, the more protection there is from UVA rays.
The grading of PA is listed below according to the Japan Cosmetic Industry Association:
PA+ → Provides UVA protection with a factor of Persistent Pigment Darkening (PPD) of 2-4. (Some UVA protection)
PA++ → Provides UVA protection with a factor of PPD of 4-8 (Moderate UVA protection)
PA+++ Provides UVA protection with a factor of PPD of 8-16 (High UVA Protection)
PA ++++ Provides UVA protection with a factor of PPD of 16 or higher (Extremely high UVA protection)
A good quality sunscreen is one that offers protection from both UVB and UVA rays. Choosing the adequate amount of SPF and PA plus signs will largely depend on the consumer’s amount of outdoor activity, weather, and exercise activity. For everyday indoor use, an SPF 15 with PA or SPF 30 with PA is sufficient. For consumers that are largely outside, exposed to sunny weather, sweat easily, an SPF of 50 or higher with PA will provide better protection. Regardless of the SPF number or PA plus signs, it is encouraged to reapply sunscreen directly as advised every 2-4 hours for optimal protection.