Sunscreen SPF and UVA Protection: How to Choose and Apply It

Sunscreen SPF and UVA Protection: How to Choose and Apply It

SPF stands for sun protection factor. It measures protection against ultraviolet B (UVB), the part of sunlight most associated with sunburn. SPF does not describe UVA protection, so the SPF number is only one part of the label. Sunburn is skin damage and increases the risk of skin cancer; people with every skin tone need sun protection, even though redness may be less visible on black or brown skin.

What should the label show?

For everyday UK sun protection, choose a broad-spectrum sunscreen with at least SPF 30 and adequate UVA protection. A UVA symbol inside a circle can indicate that a product meets the relevant European UVA standard. Check the expiry date and follow the manufacturer’s instructions.

Does SPF 50 give complete or much longer protection?

SPF 50 provides a higher tested level of UVB protection than SPF 30, but no sunscreen blocks all ultraviolet radiation. The number should not be converted into a promise that it is safe to stay outside for many times longer. Protection in use depends on applying enough, covering every exposed area, reapplying, and what happens after swimming, sweating, towel drying or rubbing. Do not use sunscreen to extend the time spent in strong sun.

How much and how often?

Apply sunscreen generously to exposed skin, including the face, ears, neck and any exposed scalp. Apply before significant sun exposure and reapply liberally and frequently according to the label, especially after water, towel drying, sweating or rubbing.

What does oil-free sunscreen mean?

‘Oil-free’ describes one aspect of a formulation. It does not by itself establish the SPF, UVA protection, water resistance, finish, sensitivity risk or whether a product will suit acne-prone skin. It is also separate from a ‘non-comedogenic’ claim. Compare the complete label and choose a texture that you can apply in sufficient quantity. Stop using a product that causes a marked reaction and ask a pharmacist or clinician for individual advice if eczema, acne, allergy, prescribed skincare or another condition makes selection difficult.

Sunscreen is one part of sun safety

Do not rely on sunscreen alone. In the UK, seek shade when sunlight is strongest, generally between 11am and 3pm from March to October, and use suitable clothing, a wide-brimmed hat and UV-protective sunglasses. Check the UV index; when it is 3 or higher, consider protecting skin and eyes. Keep babies under 6 months out of direct strong sunlight and take extra care with children.

When cosmetic advice is not enough

Blistering, marked swelling or feeling seriously unwell after sun exposure needs prompt clinical assessment. A new or changing mole or other unexplained mark should also be assessed appropriately rather than treated as a cosmetic concern.

Scope of this article

Dr Sknn is an independent private aesthetics and cosmetics clinic. This page is limited to cosmetic concerns and treatment considerations. Suitability, risks, recovery and current availability are confirmed during an individual consultation. New, changing or unexplained symptoms should be assessed by an appropriate healthcare professional before cosmetic treatment.