top of page

42. Summer Sun, Summer Has Begun - Do You Know the Equation?

Updated: Mar 21

A recipe for SPF (sun protection factor) includes ingredients in the products, the broad spectrum protection and also the skin's natural burn time. Knowing your personal equation is long would it take you to burn in natural sunlight without protection?  For example, for a fair skin it may be 10 minutes burn time, so by adding an SPF15 to the equation the skin is protected for 150 minutes (10 x 15 =150).

There are two types of sunscreen, a physical which physically reflects the sun from the skin and a chemical which allows the rays to penetrate into the skin. The ultra violet rays create a heat sensation that creates a chemical reaction in the skin which deactivates the rays helping to prevent sun damage.  For sensitive skins it is important to wear a physical sunscreen because this prevents the skin from reacting to the chemical reaction caused by the heat from the sun and the product.

Buying a broad spectrum sunscreen protects the skin against both UVB rays which are present when the sun is out and UVA rays responsible for ageing and present all year round. A broad spectrum sunscreen has the sun protection factor with a circle around it displayed on the bottle.  There are three classifications of broad spectrum sunscreen - low, medium, and high depending on the UV protection.  It is now required by the European Union that product ranges label their sunscreens with the broad spectrum symbol, protection factor and the level of protection.

Protection Levels:

Low sunscreens 6 - 10 SPF

Medium from 15 - 25 SPF

High protection from 30 - 50 SPF

Very High SPF 50+ (sun protection higher than SPF 30 is always a chemical sunscreen) What do all of the numbers mean? A general example is that an SPF15 will protect the skin from 94% of UVA rays, SPF 30 protects from 97% UVA rays and SPF 50 protect from 98% UVA rays. All sunscreens block the UVB rays which are mostly from the sun, but it's the UVA rays that are important to remember to protect your skin from all year round. This can be done by ensuring your day cream has an SPF 30+.

Dermalogica has thoroughly researched their ingredients and found an ingredient that enables a higher protection without the added chemicals. These plant oleosomes are found in the seeds of plants that carry natural vitamin E.  This newly formulated technology allows them to be mixed with sunscreens helping to boost the sun protection factor.  The natural plant extracts help to provide an emulsifying effect making the products non-irritating and creating an easily absorbed non-greasy texture to the product.

Knowing the ingredients in a product can help you understand what you are putting on your skin and what type of sunscreen or block you are buying as that aspect isn't always clearly labelled.

A physical sunscreen is good for sensitive skins, they still block the whole spectrum of ultra violet rays and the lack of chemical ingredients prevent the skin from reacting.  Look for main ingredients such as titanium dioxide and zinc oxide in these sunscreens.  

Ingredients in a chemical sunscreen are often avobenzone, octinoxate, oxybenzone, and ethylhexyl methoxycinnamate which means they can protect at a higher level. Sometimes sunscreens are a mix of chemical and physical protection ingredients which are usually ok for sensitive skins, but it's always best to test on very sensitive skins. To protect the skin for two hours of sunlight a teaspoon size amount of product is required for the face, neck and decollate and a shot glass amount of sunscreen to protect the body. If you're on holiday it is necessary to reapply your sunscreen every two hours and remember 'water resistant' sunscreens are only effective for 40 minutes in the water and protection should be re-applied once you're out of the water. By layering sun protection it helps ensure a more even coverage and that areas aren't missed leaving the skin at risk of burning.

We're lucky that over the past decade skincare brands have evolved and that sunscreen is now available in face and body moisturisers to help protect our skin all year round. If you would like a product prescription, please visit our website

16 views0 comments


bottom of page