10 May 2022

SPF Essentials

It is always SPF season but with summer around the corner, I wanted to go over the SPF essentials. We know protecting skin from sun exposure will reduce the risk of skin cancer, sunburn and premature ageing (sunspots, wrinkles, sagging skin).

What does SPF mean?

SPF is the Sun Protection Factor and indicates the level of protection against getting a sunburn only.

An SPF of 30 blocks 97% of the suns UVB rays. This means that it will take you 30 times longer to burn the skin than without SPF protection.
An SPF of 50 blocks 98% of the suns UVB rays. This means that it will take 50 times longer to burn the skin than without SPF protection.
An SPF of 100 blocks 99% of the suns UVB rays. This means that it will take 100 times longer to burn the skin than without the SPF protection.

It is important to remember that a high SPF does not work longer than a lower SPF so reapplication is the same regardless of the number.

What is the difference between UVA and UVB rays? What does broad spectrum SPF mean?

Sunlight consists of UVA and UVB rays. UVA rays prematurely age the skin, causing pigmentation issues (sun spots), fine lines and wrinkles. UVB rays are the primary cause of sunburn and skin cancers.

SPF indicates protection against UVB rays ONLY.

A broad spectrum sunscreen means that the sunscreen will protect against both UVA and UVB rays.

What is the difference between chemical and physical sunscreen?

Chemical sunscreens functin to absorb the suns rays. These formulations are easier to rub into skin without a white residue and often contain ingredients like oxybenzone, avobenzone, octisalate, octocrylene, homosalate, and octinoxate.

Physical sunscreens function to sit on the skins surface and deflect the suns rays. Formulations commonly contain zinc oxide and/or titanium oxide and are used on sensitive skin.

When should I wear SPF?

SPF should we born every single day, regardless of whether you can see the sun. Even on cloudy days, up to 80% of the suns harmful rays can penetrate into the skin. Snow, sand and water increase the need for SPF because they reflect the suns rays.

What Sunscreen Should I use?

Look for an sunscreen that offers broad spectrum protection against UVA and UVB rays with an SPF of 30 or higher that is water resistant.

Other ways to protect the skin include wearing SPF swim shirts, wide brimmed hats to cover the entire face, and sunglasses.

How much sunscreen should I use & how often should I apply it?

Most people do not apply enough sunscreen or top up enough. In generaly, most adults need about 1 ounce (enough to fill a shot glass) to protect the entire body. Sunscreen should be applied to dry sin ideally 15 minutes before going outdoors. Do not forget the tops of the feet, neck, ears, lips and the top of the head! Reapplication of sunscreen should be done every 2-3 hours when outdoors and/or after swimming or sweating.

showcasing how much sunscreen you need to apply

What type of sunscreen should I use?

This is really a matter of personal preference. For dry skin and the face, I prefer creams that can also function to hydrate the skin and give a little glow. For oily/acne prone skin, I prefer non comedogenic gels to give an overall matt finish while protecting the skin. For melasma prone skin, I prefer physical sunscreens alone or in combination with chemical sunscreens. Chemical sunscreens are not enough for pigmentation issues. I try to stay away from sprays as it can be difficult to thoroughly apply the sunscreen in adequate dosing. Here are a few of my favourites!