Summer Skin Protection: Sunscreen 101

skin cancer



The sun gives off 3 types of ultraviolet radiation, all 3 can cause skin cancer! UVA radiation goes deeper into the skin, causing skin cancer and pre-mature aging. UVA is also responsible for our summer tan. UVB radiation affects the skins surface (epidermis), these rays contribute the most to sunburns and eye damage. UVC is very dangerous, but thankfully mostly filtered out by the ozone layer. 


There are dozens of brands and formulas out there, but sunscreen ultimately falls into 2 broad categories: chemical sunscreens & physical sunscreens. Physical sunscreen works as a shield, sitting on the surface of your skin, while chemical sunscreen acts like a sponge, absorbing the suns rays and turning it into heat. You’ll find that most skin care experts advise using a physical sunscreen. Why? Firstly, the heat generated by chemical sunscreens can heat up the skins internal temperature, accelerating hyper-pigmentation, brown spots and worsen facial flushing. Chemical sunscreens also typically contain pore-clogging and irritating chemicals which will aggravate acne-prone skin. If that’s not enough to say no to already, chemical sunscreens cause major environmental damage, harming our oceans and coral reefs; if you see Oxybenzone or Octonixate in the ingredients list, steer clear! 

Physical sunscreens utilize active mineral ingredients (titanium dioxide or zinc oxide), to deflect the suns rays. Physical sunscreens do not typically block pores or cause skin irritation. They deflect the radiation away from the skin without heating it up, so they don’t contribute to hyper-pigmentation, in fact, they’ll likely help prevent it. Physical sunscreens also begin to provide protection from the moment you apply them; chemical sunscreens take up to 30 minutes to begin working – and how many times have you sprayed on your sunscreen after you were already laid out tanning?!

So why do we even use chemical sunscreens? While I always encourage my patients to opt for a physical sunscreen, the demand for chemical sunscreen exists because of their weightless feel and higher absorption. Physical sunscreens leave a white coating on the skin that some find undesirable or unattractive. 


  • The spectrum of UV radiation absorbed.
  • The amount of sunscreen applied.
  • The frequency of application.

Always choose a broad-spectrum (UVA & UVB protection) sunscreen and an SPF of 30 or higher. SPF stands for sun protection factor. SPF rating is calculated by comparing the amount of time needed to burn sunscreen-protected skin vs. unprotected skin. For example,if a person who might typically burn after 10 minutes in the sun puts on SPF 2, they have double that time before sunburn, so 20 minutes. Skin protected with SPF 15 would take 15 times longer, or 150 minutes for sunburn to occur in this person. 

Sunscreen should form a film on the skin when initially applied. Use about a teaspoon amount for your face, and about 2oz (4 tablespoons) for your body and be sure not to forget your lips! Lip balms of SPF 15 or higher please. If you’re using a chemical sunscreen, you’ll need to wait 30 minutes before heading out into the sun, physical sunscreen users can head straight out after applying. Reapply every 2 hours, more often if you’re sweating or in the water or if you know you’re prone to burns. You should always apply your sunscreen after your moisturizer, but before makeup. 

Sunscreen should be used daily, regardless of your skin tone or how prone to burning you are. If you aren’t convinced, here is a link to the stats // Finally, don’t use expired sunscreen; it’s lost its potency and won’t provide the important protection your skin needs. 

To learn more about how to protect your skin, and support healthy skin aging please book a skin health assessment (hyperlink to cosmetic dermatology page).

To book your initial skin health consultation please call 604-670-0590 or click here (Online Booking)

Happy summer everyone!

Dr. Alaina

You might also want to read our previous blog, Move Over Anti-aging! We’re All About Healthy Skin Aging Using This Simple Integrated Approach



