Choosing the right sunscreen may not be as easy as one thinks. UVA, UVB, SPF, photostabilty and water resistant: these are just some of the terms you’re likely to encounter. Let’s try to clear things up!
UVA and UVB radiation
It’s important to pick a sunscreen that blocks both UVA and UVB rays, since both types of radiation damage skin.
UVA rays penetrate deep into the skin and contribute to its premature aging. Creating an immediate tanning effect, these rays do not cause a protective tan. Actually, they are responsible for allergic reactions in people who are intolerant to sun exposure, and they can also lead to pigmentation disorders (e.g. dark spots). Photo sensitivity due to some medications is also caused by UVA rays, which are also the culprits behind certain types of skin cancer.
UVB rays cause sunburn, a type of skin damage that should be avoided at all costs. They also account for persistent tans, browning and thickened skin since they increase melanin production. As a result, UVB rays significantly increase the risk of skin cancer .
For optimal performance, sunscreen must contain filters capable of absorbing or deflecting UV radiation. To provide very effective UVA and UVB protection, products may contain several different filters with complimentary properties.
Here are a few examples of common UV filters found in today’s sun protection products:
- Mexoryl (SX or XL)
- Titanium dioxide
- Zinc oxide
- Avobenzone (Parsol 1789)
- Tinosorb M and S (bisoctrizole and demotrizinol)
These products are generally regarded as safe by the medical community. Some may not provide adequate UVA and UVB protection, however. For greater reassurance, always look for the Canadian Dermatologists Association logo, found on sunscreens by brands that request this seal of approval. Their products contain:
- An anti-UVB sun protection of at least SPF 30
- A wide spectrum anti-UVA
Look too for the Health Canada icon of a UVA in a circle.
If you’re not sure, ask your pharmacist! He or she can let you know which UV filters can be found in a given formula and whether or not they provide the protection you need.
The latest UV filters, such as Mexoryl SX and XL, Tinosorb M and S, are photostable and deliver a high degree of protection at a relatively low concentration compared to other active ingredients. This reduces your chances of skin irritation—great news for people with sensitive skin!
Photostability and water resistance
To perform well, a sunscreen must be able to withstand sun exposure without deteriorating. This is known as its “photostability.” Mexoryl SX and XL as well as Tinosorb S and M sun filters are known for their high level of photostability.
Water resistance is another key factor, especially for athletes who transpire a lot or beach-goers who are frequently in and out of the water. But don’t forget to reapply: even water-resistant products should be reapplied frequently in extended sun exposure.
Sun protection factor (SPF)
A key factor to consider when buying sunscreen is its SPF (its “sun protection factor”). The SPF rating indicates the level of protection the product provides against UVB rays.
The higher the SPF, the more UVB rays blocked. A sunscreen with SPF 30 will block 96.7% of UVBs, while a SPF 60 will block 98.3%. No sunscreen offers 100% protection.
There is no protection index for UVAs. To find out if a given product offers protection, look to see that the label specifies that it is “Broad spectrum” or offers “UVA protection” (or something similar).
The Canadian Dermatology Association (CDA) recommends the use of a broad spectrum sunscreen with an SPF of at least 30, starting as early as six months of age.
Adequate protection depends on proper use
The more easily you sunburn, the higher your SPF should be. For maximal protection, sunscreen needs to be applied properly and in adequate quantity! But don’t be lulled into a false sense of security by a high SPF number. It bears repeating that sunscreen will not protect you properly if you do not use enough of it or if you fail to reapply it as needed.
The rules for applying sunscreen are the same for all sunscreens, regardless of SPF:
- Apply 30 minutes before going outside. A person of average size, wearing a bathing suit, needs about 2 tablespoons (30 ml) of product to cover his or her entire body.
- Reapply every 2 hours.
- Reapply after swimming or perspiring heavily.
- Protect your lips with an SPF 30 lip balm.
- Don’t forget sensitive areas, like around your eyes, ears and nose.
What about children?
According to the CDA, babies under 6 months of age should not be exposed to the sun. Their skin is thin and vulnerable, and their sun defense mechanism is not yet 100% formed. Keep them out of direct sunlight, dress them in lightweight, loose-fitting clothing that covers their whole bodies and make sure they wear a sun hat.
If sun exposure cannot be avoided, use a small amount of sunscreen on exposed body parts. Physical filters, such as zinc oxide or titanium dioxide, are a good choice for children.
Choosing a product for sensitive skin
If you have sensitive skin, you should choose a sunscreen without parabens or perfumes. You can also make sure the labels mentions “Hypoallergenic” or “For sensitive skin.”
Products containing mineral filters (titanium dioxide or zinc oxide) and some chemical filters (particularly, Meroxyl and Tinosorb) are generally good choices for sensitive skin.
There are also non-comedogenic products, which are an excellent option if you have acne.
Cream, lotion or spray?
In addition to SPF and UVA protection, sunscreens come in a range of products: for kids or athletes, as a lotion, spray, stick or cream. Which one you choose depends on your specific needs and preferences. But don’t be shy to ask for advice from your pharmacist or beauty consultant in choosing the best product for you.
Despite our best intentions, sometimes we get a sun burn all the same. There are specially designed products to gently hydrate the skin without aggravating the irritation caused by the sun. Some products contain aloe while others use thermal water, which is sometimes antioxidant enriched, to fight the harmful effects of sun on the skin.
Did you know that certain medications can make your skin more sensitive to the sun? This reaction, known as “drug-induced photosensivity,” is mostly associated with UVA rays. Your pharmacist can tell you if a drug you are taking can cause photosensitivity.
Here’s another interesting fact: in Canada, sunscreens are considered drugs, not cosmetics. If you have questions about sun protection, talk to your family pharmacist or beauty consultant . They’re here to help!