PreventionPatient educationN/A (prevention)
Photoprotection and sunscreen
Sunscreen; sun cream; SPF; UVA-PA; photoprotection
Sunscreen is one component of photoprotection — alongside shade, clothing, hats and sunglasses — and is the most over-relied-upon and under-applied. Real-world sunscreen use delivers a fraction of the labelled SPF protection because most people apply too little, too late and reapply too rarely. Effective counselling focuses on adequate quantity (~ 30 mL / 6 teaspoons per adult body application), correct timing (15–30 minutes before sun exposure and every 2 hours), and emphasises that sunscreen complements rather than replaces shade, clothing and avoidance during the peak UV hours.
CurrentLast reviewed 15 May 2026
SPF, UVA-PA and broad-spectrum
- SPF — Sun Protection Factor; UVB-specific. SPF 30 blocks ~ 97% of UVB; SPF 50 blocks ~ 98% — the marginal gain above SPF 30 is small.
- UVA protection — in the UK shown by the Boots Star rating and the EU UVA-in-a-circle logo (denoting UVA ≥ 1/3 of the SPF); the PA system (PA+ to PA++++, based on persistent pigment darkening) is used in Asia.
- Choose broad-spectrum SPF 30+ with UVA-PA at minimum for everyday use; SPF 50+ for extended outdoor activity and Fitzpatrick I–II skin.
- Water resistance — "water-resistant" implies maintained protection after 40 minutes immersion; "very water resistant" 80 minutes.
Mineral vs chemical
- Mineral (physical) filters — zinc oxide, titanium dioxide. Sit on the skin surface and reflect/scatter UV. Better tolerance for sensitive skin and infants; visible cast on darker skin is the main drawback.
- Chemical (organic) filters — avobenzone, octocrylene, octinoxate, mexoryl, tinosorb, bemotrizinol. Absorb UV and dissipate as heat. More cosmetically elegant; some have potential systemic absorption concerns under occlusive use.
- Both classes — efficacious when used correctly; patient preference often determines compliance.
- Mineral preferred — children, sensitive skin, after laser / Mohs / wound healing.
Application practicalities
- Quantity — 2 mg/cm² is the ISO test standard. For an average adult body this equates to ~ 30 mL (6 teaspoons): roughly 1/2 tsp for the face/neck, 1/2 tsp each arm, 1 tsp each leg, 1 tsp front torso, 1 tsp back.
- Real-world use delivers half this or less — patients should apply more generously than feels reasonable.
- Apply 15–30 minutes before sun exposure.
- Reapply every 2 hours, after sweating, swimming, or towel drying.
- Cover frequently missed areas — ears, lips (use SPF balm), neck, dorsal hands, feet, scalp (in those with thinning hair).
Clothing, hats and shade
- Photoprotective clothing — UPF rating; tightly woven, dark colours block more UV; UPF 50+ blocks ≥ 98% UV.
- Wide-brimmed hat (≥ 7.5 cm brim) significantly reduces facial UV.
- Sunglasses — UV 400 / CE-marked; reduce ocular UV exposure (cataracts, conjunctival melanoma).
- Shade during peak UV hours (10 am–4 pm in UK summer) is the single most effective intervention.
- Sand, snow and water reflect UV — protection still required in shaded conditions on these surfaces.
Patient counselling
- Sunscreen is a complement to, not a replacement for, behavioural sun avoidance.
- Daily SPF 30+ broad-spectrum on the face, neck, dorsal hands and other chronically-exposed sites — even in UK winter for cumulative exposure reduction.
- Children — formal mineral sunscreens from 6 months; under 6 months protect with shade and clothing.
- Vitamin D balance — see vitamin D; supplementation is preferable to sun exposure for vitamin D maintenance in high-risk groups.
- OTRs and other high-risk groups need formal photoprotection counselling and prescription sunscreen on FP10 (e.g. Sunsense / Anthelios).
References
- Bens G. Sunscreen — formulation, regulation and effective use. Adv Exp Med Biol; 2014.
- NICE NG34. Sunlight exposure: risks and benefits. London: NICE; 2016. NICE PH32. Skin cancer prevention. London: NICE; 2011 (last updated 9 February 2016; remaining recommendation covers shade provision).
- Cancer Research UK. Sun safety advice.
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