SPF: Your Definitive Guide
If you ask any dermatologist their top tips for healthy skin, sunscreen is sure to feature heavily.
SPF’s importance within your skincare routine cannot be overstated – its role is critical in protecting the skin from the harmful UV rays that cause premature ageing, hyperpigmentation and skin cancer.
In today’s journal entry, I share everything you need to know about sun protection: from the benefits of chemical and mineral SPFs, to the best options for the face and body, and answer all the most frequently asked sunscreen questions.
Chemical SPF vs Mineral SPF
When it comes to selecting sun protection, there are two choices: mineral or chemical sunscreen.
Mineral SPF
Mineral sunscreen creates a physical barrier on top of our skin which reflects UV rays. Mineral sunscreen offers the most broad protection available, even shielding from UVA rays coming through windows.
One of the key benefits of mineral SPF is its suitability for sensitive or acne-prone skin, making it a popular choice for children and individuals with skincare concerns. Additionally, mineral sunscreens start working immediately after application. The environmental benefits of mineral SPF have also driven its popularity, many formulations are reef-safe, meaning they do not contain the harmful, coral reef-bleaching chemicals that are found in many chemical sunscreens.
It is important to note, however, that mineral sunscreens are not always as water and sweat resistant as chemical options (so regular reapplication is crucial), and that they can leave a white cast (though newer formulations are looking to address this with tinted or ultra-sheer formulations).
Chemical SPF
A chemical sunscreen contains ingredients that absorb and transform UVA and UVB rays into heat. Chemical sunscreens are generally more lightweight, water-and-sweat resistant and suitable for most skin types (though some ingredients can cause sensitivity). It is important to apply chemical sunscreens at least 30 minutes prior to sun exposure in order to ensure adequate absorption and efficacy, and (as mentioned above), the formulations of many chemical sunscreens can adversely affect the environment around us.
SPF Levels Of Protection
SPF means sun protection factor, a measurement of the duration that sunscreen should protect the skin from UVB rays. This is assessed by comparing how long redness (or erythema) takes to appear on unprotected skin and protected skin when exposed to a specific level of UV rays. Therefore, theoretically, a sunscreen with an factor of 30 should shield the skin for 30 times longer than unprotected skin.
The difference between SPF levels is determined by how much UVB protection they offer: SPF 15 blocks about 93% UVB rays, SPF 30 blocks around 97% of UVB rays, whilst SPF 50 blocks approximately 98% of UVB rays.
With this said: in reality, the protection offered varies, as it is affected by the quantity of sunscreen applied, whether you are swimming, sweating or towel-drying and the UV index on any given day. I would recommend always selecting a factor of 30 or higher, and making sure you are reapplying at regular intervals throughout the day (more on that shortly).
SPF FAQs
My moisturiser, concealer and foundation all have SPF, is that enough?
Yes and no. When it comes to moisturiser, if it is factor 30 or above and you are using at least two-finger lengths of product each morning, that should be adequate on a normal day.
When it comes to cosmetics, whilst using a foundation or powder with SPF isn’t a bad idea, it is thought that to adequately protect your face you’d need seven times more foundation or 14 times more powder than is usually used.
As such, it is sensible to commit to daily use of a separate broad-spectrum SPF of factor 30+ to truly protect against skin-damaging UVA and UVB rays.
How often should I reapply sunscreen?
It is important to reapply sunscreen every two hours. If you are using a chemical sunscreen, you must apply at least 30 minutes ahead of sun exposure (mineral sunscreens offer immediate protection, so can be applied just before you leave the house).
However, it is also crucial that you also avoid the sun where possible – covering up with clothing and hats, and staying out of the sun in the middle of the day when it is at its hottest.
Can I use body SPF on my face?
In theory, yes – as the SPF protection is the same. However, I would recommend choosing an SPF specifically formulated for the face to avoid clogged pores or exacerbating any existing skin concerns.
The sunscreens that have been designed for your face tend to be more lightweight and easily absorbed. This means that not only are they generally non-comedogenic, but they also are less likely to interfere with any cosmetics you are applying on top. There are also many facial sunscreens that are created to work with different skin types – whether dry, oily or combination skin.
My SPF Recommendations
Best SPF For The Face
For Pigmented Skin: Mesoestetic Mesoprotech Melan 130 Pigment Control is very high-factor protection that works well for pigmented or blemished skin. It is tinted (which enhances protection), and the inclusion of azeloglycine helps even skin tone.
For Acne-Prone Skin: EltaMD UV Clear is formulated with 5% niacinamide to help reduce the appearance of blemishes on your skin.
For Dry Skin: Ultra Violette Supreme Screen Hydrating Facial Skinscreen SPF 50+ is high-protection and hydrating, thanks to the inclusion of kakadu plum.
Best SPF For The Body
For Sensitive Skin: La Roche Posay’s Anthelios range offers broad spectrum protection without increasing skin sensitivity.
For Dry Skin: Nuxe Melting Sun Lotion Very High Protection SPF50+ increased skin hydration by over 100% when tested.
