Sunscreen tips: how much to use and when to reapply

As the summer season gets underway, many may be exposed to more and more sun. Dr. Renee Beach, a dermatologist, told CTV’s Your Morning on Monday that without skin protection, this exposure can cause DNA damage, which can develop into skin cancer.

Beach says that while many should only wear sunscreen in the summer, protecting the skin should be “year-round.”

“Even if we can’t see the sun… we still have UVA (Ultraviolet A),” she said. “So those are the rays that come through windows[and]windshields. It’s the rays that we sometimes see coming through, say, the reflection of snow.”

According to Beach, when exposed to direct sunlight, people come into contact with UVA and ultraviolet B rays (UVB). Sunscreen is necessary to protect the skin.

“SPF stands for sun protection factor, and what you’ll often hear is that SPF 30 is what should be on our skin,” Beach said. “The reason why is because that equates to about 97 percent of the ultraviolet radiation or UV protection from our sunlight during the day.”

Applying the right sunscreen and the right amount are other important factors in protecting the skin.

Beach recommends that people use about a quarter teaspoon of sunscreen on the face. If they apply sunscreen to both the face and neck, they should use about half a teaspoon.

“If we look at the whole body, that’s closer to a shot glass or 30 milliliters,” she said.

That amount often needs to be reapplied depending on the activity, Beach said. If an adult is outdoors and doing activities such as running, biking, or swimming, she suggested reapplying sunscreen every two hours.

But for kids, the amounts for reapplication and sunscreen should be different, Beach said.

To make sure kids aren’t exposed to high levels of UV rays, Beach said it’s best to cover them up.

“They should have a hat with a brim around it, and they should also wear rash clothing, so the longer sleeves,” she said. “Then you really just want to keep them out [of the sun] during those peak hours, usually around 11 a.m. to 3 p.m.”

Click on the video at the top of this article to watch the full interview and hear all of Beach’s tips.