Pharmacy Corner
Sunscreen: Stay Safe in the Sun What is Sun Protection Factor (SPF)?


Sun Protection Factor or SPF tells us about how much time the sunscreen protects us from the sun before UVB rays start to burn the skin.1,2

For example, if it takes 20 minutes of sun for your unprotected skin to start turning red, then using a sunscreen with SPF 30 should, in theory, take 30 times longer for you to get sunburn – about 10 hours.1

These calculations are not perfect, because sweating, swimming and using a towel can remove the sunscreen from your skin. Never look at using a sunscreen as a reason to stay longer in the sun.2

The amount of UVB radiation absorbed for a sunscreen with an SPF 15 is 93% but for an SPF 30 it is only 4% more at 97%.4 That means that wearing SPF 30 does not give you twice as much protection as SPF 15.


The CDA recommends sunscreens with SPF 30 for daily use.2

How do I choose a sunscreen?

The Canadian Dermatology Association (CDA) runs a sun protection program and labels sunscreen products that meet their standards and provide safe and effective sun protection.5 Any product with this logo is perfume-free, hypoallergenic, a minimum of SPF 30 and offers great protection against the sun.

When selecting a sunscreen, choose a product with the CDA logo to guarantee that the sunscreen works and is safe.2 There is also a list of CDA-recognized sunscreens and other products containing sunscreens.


Who should use sunscreen?

Everyone over 6 months of age should use sunscreen every day.4 This is not just during the summer or on your southern holiday; it means any day that a person leaves the house.

Children under 6 months should not wear sunscreen because it is common for the sunscreen to irritate their very sensitive skin.4 However, a baby’s skin is also extra sensitive to the sun’s rays, so shade and protecting their skin with clothing can help to protect them.4

When do you use sunscreen?

Sunscreen should be applied every day, no matter the season.7 During the winter, the sun’s damaging rays can even reflect off of the snow, so you could be getting twice as much exposure to UV rays.2,7 Clouds don’t offer any protection because they don’t filter UV light, so sunscreen should be applied even on cool, cloudy days.3,4