We often hear that a good skincare routine involves protecting our skin from the sun’s harmful ultraviolet rays (also known as UV rays) by covering up and using a good sunscreen. In fact, certain studies show that diligent daily sunscreen application can slow or prevent the onset of wrinkles and sagging skin. One question that comes to mind is: what exactly makes a good sunscreen?
WHAT SUNSCREENS DOES
There are two UV types that reach the earth’s surface – UV A (290 to 320 nm) and UV B (320-400 nm). Nm stands for nanometers which are the measurement of this kind of light and is a billionth of a meter. It is misleading to call some sunscreens as such, because they only protect against one type of UV ray – namely UV B – while others protect against both UV A and UV B. Those that only protect against UV B raise major concern since the majority of UV rays that reach us are UV A (estimated at about 95%) and these are the ones that are coined “aging rays” since they play a big part in contributing to signs of premature aging including fine lines, wrinkles, and hyperpigmentation. The other 5%, the UV B rays, are known to mainly affect the epidermis (i.e. top layers of the skin) and, although they do contribute to the signs of aging, they are also the major cause of sunburns.
If you’re interested in learning more, explore our guide on the damage UV rays causes skin that covers the different types out there as well as best practices to abide by.
HOW IS UV PROTECTION MEASURED?
SPF (Sun Protective Factor) measures the protection against UV B rays provided by a sunscreen. The SPF number represents the degree of sunburn protection in relation to the length of sun exposure. However, being that the intensity of sun exposure changes depending on different factors including the length of exposure, time of the day, geographic location, seasons and weather condition, the amount of time it takes to burn will also differ.
As an example, let’s say your skin would normally burn after 10 minutes without sunscreen. If you applied an SPF 15 sunscreen in the same conditions, it would allow you to stay in the sun without burning for approximately 150 minutes (a factor of 15 times longer). However, if you were in harsher conditions like the mountains in winter and wore SPF 15 you might burn a lot faster then you normally would.
Recommendation: Plan the level of SPF according to where you are and the conditions you’re facing.
Interestingly, SPF ratings don’t actually mean much beyond a certain point. SPF 15 sunscreen is estimated to block 93% of UV B radiation, SPF 30 is estimated to block 97%, and finally, SPF 50 is estimated to block 98% of UV B radiation. Once you go above SPF 50, the increase of protection in UV B radiation would be minimal. In fact, within the European Union, Australia, and hopefully soon in the United States, regulations have been updated to not allow any labels that show labels with an SPF above 50. That said, for preventative anti-aging purposes it’s recommended to go with at least SPF 30 (or higher) for daily wear.
SPF labels in countries including Australia, the EU, New Zealand, and the US are quite similar. An approximate guideline is provided below:
Low protection: SPF 6 & 10
Medium/moderate protection: SPF 15, 25, 30
High protection: SPF 30 & 50
Very high protection: SPF 50+
UV A PROTECTION
Since SPF mainly measure UV B protection, you are probably wondering how protection from UV A rays (the ones that makeup 95% of UV rays and are commonly known as aging rays) is measured. Brands in Asia and Europe have adopted a system called UVA–PF, which is measured in PPD (Persistent Pigment Darkening) – the changes in skin’s pigmentation from UV A radiation after 2-4 hours of sun exposure. The [PPD] protection index is determined as the ratio of the UVA dose required to produce a minimally perceptible pigment response on sunscreen-treated skin to the dose for unprotected skin. 1
The PPD rating on a sunscreen is a factor (multiplier) that explains how many more times the amount of UV A rays to which skin may be exposed with protection than without protection. So if the PPD rating was 16, that theoretically means skin would be able to take a dose of UV A rays 16 times more intense than it could without that level of protection. The PPD system is generally used in Europe, while in Asia the PA (Protection Grade of UVA rays) system is used and works off PPD measurement.
THE EUROPEAN UNION’S UV A LOGO
As a visual representation, the European Union has introduced a symbol for UV A protection for each sunscreen that has UVA–PF (PPD) protection of at least a third of the labeled SPF.
Although neither the PPD nor the PA systems are as precise as SPF, they are currently the go-to measurement system for UV A protection.
THE 4 LEVELS OF PA
1. PA+ : corresponds to a PPD protection between 2 and 4
2. PA++ : corresponds to PPD protection between 4 and 8
3. PA+++ : corresponds to PPD protection between 8 and 16
4. PA++++ : corresponds to PPD protection of more than 16.
The higher the PA or PPD rating, the higher the protection offered.
The term broad spectrum is used to identify sunscreens that offer protection against both UV A and UV B rays. Being that UV A and UV B rays are part of the same spectrum, a value called critical wavelength is used as the measurement for the amount of UV protection. In order to be labeled broad spectrum across the EU and US, the sunscreen must have a critical wavelength of at least 370 nm, which gives protection for 90% of the UV spectrum.
Recommendation: For preventative anti-aging, we recommend looking for a sunscreen that offers Broad Spectrum in Australia, Canada, and the US, and at least “High” protection in Europe. Like we mentioned earlier, you should also look out for SPF 30 (or higher). In Europe, look for UV A logo as well as a PPD rating of 16+ (preferably higher), and for a Pa++++ rating in Asia.
INGREDIENTS TO LOOK OUT FOR
Physical sunscreens, sit on the surface of the skin and work by deflecting or scattering UV rays. The two most popular ones are made up of natural minerals, which are ground into a fine powder and don’t break down as fast with sun exposure as with chemical sunscreens. Zinc oxide was once known for leaving a highly visible white cast on the skin and making people look like they were wearing bad makeup, but recent technological advances like micronizing have minimized this unsightly effect. Both are regarded safe and do not cause free radical damage.
Zinc oxide is able to protect the skin against the entire spectrum of UV B and UV A from 290-400 nm.
Titanium dioxide protects against UV B rays, but not the full spectrum of UV A rays, and gives the best coverage of 290-350 nm and decent coverage of 350-400 nm. The ingredient may cause breakouts for those with sensitive skin.
A combination of Zinc Oxide and Titanium Dioxide gives powerful protection for the whole range of the UV spectrum from 290 to 400 nm.
THE TRUTH BEHIND MICRONIZED INGREDIENTS
As mentioned above, the process of micronizing ingredients like Titanium Dioxide and Zinc Oxide provides cosmetic benefits like making a sunscreen easier to spread and minimizing the formula’s white cast, but it also provides more scientifically relevant benefits. Many experts believe that micronization increases the protection capabilities of the sunscreen agents but, on the other hand, some fear that by being micronized there is a higher possibility of ingredients being absorbed. Truth be told the absorption rate does increase, but multiple studies indicate that the levels are minimal – so in this case, the benefits outweigh the risks.
Here are some physical sunscreens we recommend that provide a powerful level of protection against the damage caused by UV rays:
Skinceuticals Physical Fusion Defense ($26.54)
Best For: Normal to Combination & Sensitive Skin
The highly rated fluid SPF 50 sunscreen is lightweight, provides hydration and still works great under makeup. UV protection is provided by the combination of 5% Zinc Oxide, 6% Titanium Dioxide and has a tinted formula to help hide white cast. The sunscreen is also fragrance-free, feels great on the skin, and dries with a semi-matte finish to avoid an overly dewy situation.
Exuviance by Neostrata Sheer Daily Protector SPF ($37.45)
Best For: Normal to Combination Skin
Gentle and fragrance-free with the maximum recommended of SPF 50 and the highest PA level, this tinted fluid sunscreen is another great choice for preventing the harmful effects of the sun. In addition to containing both 6.0% Zinc Oxide and 7% Titanium Dioxide, it contains antioxidants including Vitamin E to boost the formula. Note that there are some thickening agents in this product that may make it feel a little heavy.
Clinique Pep Start Daily UV Protector ($19.50)
Best For: Normal, Combination & Sensitive Skin
Clinique’s broad-spectrum sunscreen has an SPF of 50 and is mineral-based, made from a combination of 4% Zinc Oxide as well as 6.3% Titanium Dioxide. Not only is the formula lightweight but the peach tint blends well with skin and dries in a matte finish. Other product benefits include that it is fragrance-free and doesn’t have parabens, sulfates or phthalates.
Best For: Normal To Combination Skin
bareMinerals Prep Step, mineral based, broad-spectrum sunscreen helps to hydrate as it protects. Although tinted, the formula dries with a nearly invisible white cast (unless you’re very fair) as it has an extremely high level (23.8%) of Zinc Oxide, combined with 4.1% Titanium Dioxide in order to provide a strong barrier against UV rays when used correctly. The light-weight lotion works well as a primer under makeup and is both fragrance as well as oil free.
Md Solar Sciences Mineral Creme Broad Spectrum SPF 50 ($30)
Best For: Normal to Oily Skin
Md Solar Sciences 50% SPF cream packs in multiple skin-beneficial ingredients like Green Tea and Pomegranate Extract that when combined with the 2% Titanium Dioxide as well as the 17% Zinc Oxide provides a high level of protection from the sun’s UV rays. Although the formula is tinted and dries sheer, the white cast may be visible on darker skin tones.
Josie Maran Argan Daily Moisturizer SPF 47 Protect + Perfect ($30.50)
Best For: Normal to Dry Skin (not prone to breakouts)
The winning combination of rich Argan Oil and hydrating Aloe Vera has this broad-spectrum sunscreen (9.4% Zinc Oxide & 5.9% Titanium Dioxide) packing an intense moisturizing boost. Other notable ingredients we love include Green Tea, the free radical fighting antioxidant known for its anti-inflammatory properties, and the healing Vitamin E. Not only is the formulation blendable with a tint to mask the white cast mineral sunscreens often have but it also works great under makeup. For those of you that fall on the lighter side of the skin spectrum, the non-tinted version might be more of a suitable match.
Murad City Skin Age Defense Broad Spectrum Sunscreen ($65)
Best For: Combination, Dry & Sensitive Skin
Murad’s 100% mineral-based broad-spectrum sunscreen combines 10% zinc oxide with 2.7% Titanium Dioxide to provide SPF 50 (PA++++) protection from the sun’s rays. Although on the pricier side, the highly blendable formula avoids leaving a white cast on most skin-tones as well as provides anti-aging support through ingredients like Vitamin C (Ascorbic Acid). Last but certainly not least it should be noted that the sunscreen is free of parabens and sulfates.
First Aid Beauty’s Ultra Repair Pure Mineral Sunscreen Moisturizer ($30)
Best For: Normal To Dry Skin
Through the replenishing power of Shea Butter, Ceramides and Triglycerides along with 4.6% Zinc Oxide as well as 6.3% Titanium Oxide, FAB’s broad-spectrum sunscreen help to boost skins’ hydration levels all while protecting it from the harmful, aging effects of the sun. The whipped cream like texture certainly leaves skin supple but as the formula is untinted it may work best for those on the fairer end of the color spectrum. Although, when well-blended the sunscreen leaves minimal to no white cast. Other notable ingredients to look out for include the antioxidants Licorice Root, Feverfew, and White Tea Extracts that help to boost the rejuvenating benefits of the moisturizer.
KEY UV PROTECTION BOOSTERS
The theory of antioxidants in sunscreens has become increasingly popular over the last few years and for good reason. Certain antioxidants can help boost the skin’s natural defense system against UV rays, so instead of just taking supplements to heal damage, you can actually prevent it from ever happening.
Keep an eye out for Vitamin C as a booster for sun protection. This is because it packs a lot of protection by controlling melanin production (which causes brown spots) and, as a natural free-radical warrior, can boost your skin’s defensive system against UV rays.
Exposure to the sun leads to redness, inflammation, and damaged cells that reproduce at a rapid rate. Vitamin E can help reduce the effects of UV-induced damage by counteracting and minimizing inflammation. As an antioxidant, Vitamin E helps minimize the formation of sunburn cells as well as prevent free radical damage.
Studies show that the combination of Vitamin C and E provide advanced protection from UV damage, especially when combined with a broadband sunscreen. We like to apply these vitamins in the form of a serum prior to applying sunscreen. Read our article here about one of the best Vitamin C Serums on the market that really works.
Green tea contains catechins, which are signaling molecules that assist in providing sun protection. This antioxidant protection blocks collagen degeneration known for accelerating the aging of cells, so this little ingredient is a definite must-have when it comes to seeking a sunscreen with anti-aging and UV protection.
Another key ingredient to note is a-lipoic acid. This will help reduce inflammation that can be caused by sunburns and can prevent UV light immunosuppression, which can lead to severe burns and exposure.
Chemical sunscreen mostly works by absorbing UV rays and they often get a bad reputation for being unstable as well as rapidly breaking down when exposed to the sun. Although rather dependent on the type of chemical sunscreen this chemical instability can result in the release of free radicals. Below are some of the popular chemical-based sunscreen agents available in North America:
Avobenzone is relatively non-irritating and protects against an entire range of UV A light from 310-400 nm. It does break down with sun exposure when used alone so it needs a photostabilizer such as Tinsorb S and M (see below for more information).
Mexoryl SX and XL protect against both UV A and UV B rays from 290-400 nm and don’t degrade or lose effectiveness with sun exposure. They are also minimally absorbed into the body through the skin, though a downside is these ingredients have been known to be a skin irritant.
Tinosorb S and M (Ecamsule) protects against UV A and UV B rays from 280-400 nm, rarely cause skin irritation, and neither degrades nor loses effectiveness with sun exposure. They are actually a hybrid chemical and physical sunscreen since they both absorb and scatter UV rays.
WHY CONSIDER AVOIDING CHEMICAL BASED SUNSCREENS?
Many chemical sunscreens, at least the ones that are widely available in North America need the support of a combination of chemical protection agents to prevent degradation from sun exposure and, in some cases, to ensure the formula’s stability. Studies have shown that the damage and the overall health implications from the release of free radicals from these types of sun protection agents are still unclear, especially when they are exposed to prolonged sun exposure.
THINGS TO NOTE
Below are some general guidelines to note before using a sunscreen:
- As chemical sunscreens need to be absorbed into the skin, they should be applied to skin 20 to 30 minutes before any sun exposure.
- Stronger physical sunscreens don’t always come off completely with just a water-based facial cleanser and often need to be removed with a good oil-based cleanser.
- Although sunscreens should be the last step of your skincare routine before you head out the door you may want to apply your makeup on afterwards.
- Avoid sunscreens, especially fluid ones that have high levels of bad alcohols (like SD Alcohol, Ethanol, Denatured, Isopropyl, Methanol or Ethyl Alcohol.) as they have been linked to damaging the skin’s barrier as well as are a cause of premature aging.
- While all sunscreen breaks down with UV exposure, physical ones are supposed to take longer to do so. To maintain maximum UV protection, experts recommend sunscreen being applied every 2 hours. If it’s an especially humid day where you find your sunscreen is sweating off, it may be a good idea to reapply more frequently,
GUIDELINES FOR APPLICATION
Below are some estimations for the amount of sunscreen needed to protect your skin from UV damage :
- Face: 1/4 teaspoon of sunscreen
- Neck 1/4 teaspoon of sunscreen (front and back)
- Chest: 1 teaspoon of sunscreen
- Back: 1 teaspoon of sunscreen
- Arms: 1/2 teaspoon of sunscreen per arm
- Legs: 1 teaspoon of sunscreen per leg
Sometimes the smallest things can make the biggest difference. Buying an effective sunscreen may seem complicated (and pricey) but using one is still one of the best preventative measures against premature aging. Although it’s important to keep in mind that a good skin care routine will combine both products as well as treatments.