# Sunscreen filters (UV filters)

> Source: https://thecastindex.com/beauty/ingredients/sunscreen-filters — updated 2026-09-25

Sunscreen filters absorb or reflect ultraviolet light. SPF measures protection against UVB, the main cause of sunburn; UVA protection is shown by a UVA logo or star rating in the UK and by PA ratings on Korean and Japanese products. Mineral filters (zinc oxide, titanium dioxide) and modern chemical filters can both protect well.

- Also on labels as: SPF, Zinc oxide, Titanium dioxide, Avobenzone, Tinosorb S, Mineral and chemical filters, PA++++
- Type: UV protection

## What it does

- Reduces sunburn, sun-related skin damage and the risk of skin cancer
- Helps prevent the look of premature ageing and dark marks from UV
- Supports results from actives such as retinoids and acids

## Who it suits

Everyone. The NHS recommends SPF 30 or higher with at least four-star UVA protection.

## How to use it

1. Apply generously as the last step of your morning routine
2. Reapply regularly outdoors, and after swimming, sweating or towelling
3. Use enough — most people apply far less than the amount used in testing

## Take care

- SPF in make-up alone is rarely applied thickly enough for full protection
- Mineral formulas can leave a white cast on deeper skin tones; tinted versions help

## What it pairs with

Always the final skincare step in the morning; wait for serums to settle first.

## Products in the catalogue that list it

- [La Roche-Posay Anthelios UVMune 400 Invisible Fluid SPF50+](https://thecastindex.com/beauty/la-roche-posay-anthelios-uvmune-400-invisible-fluid-spf50)
- [Beauty of Joseon Relief Sun: Rice + Niacinamide SPF50+](https://thecastindex.com/beauty/beauty-of-joseon-relief-sun-rice-niacinamide)
- [Beauty of Joseon Daily Relief Sunscreen SPF 40](https://thecastindex.com/beauty/beauty-of-joseon-daily-relief-sunscreen)
- [Round Lab Birch Juice Moisturizing Sun Cream SPF50+ PA++++](https://thecastindex.com/beauty/round-lab-birch-juice-moisturizing-sun-cream)
- [SKIN1004 Madagascar Centella Hyalu-Cica Water-Fit Sun Serum](https://thecastindex.com/beauty/skin1004-madagascar-centella-hyalu-cica-water-fit-sun-serum)
- [COSRX Ultra-Light Invisible Sunscreen SPF50 PA++++](https://thecastindex.com/beauty/cosrx-ultra-light-invisible-sunscreen-spf50)
- [ILIA Sun Serum Mineral Sunscreen SPF 50](https://thecastindex.com/beauty/ilia-sun-serum-mineral-sunscreen-spf-50)
- [e.l.f. Cosmetics Halo Glow Skin Tint SPF 50](https://thecastindex.com/beauty/elf-halo-glow-skin-tint-spf-50)

## Questions

### What SPF should I use?

The NHS advises SPF 30 or higher, with UVA protection of at least four stars (or the UVA logo in a circle), applied generously and reapplied.

### What does PA++++ mean?

PA is a UVA rating used on many Asian sunscreens; PA++++ is the highest grade. It is broadly comparable to a high UVA star rating.

### Are mineral sunscreens better than chemical ones?

Not inherently. Both can offer high, broad-spectrum protection. The best sunscreen is one you will apply generously every day.

## Sources

- [NHS — Sunscreen and sun safety](https://www.nhs.uk/live-well/seasonal-health/sunscreen-and-sun-safety/)
- [American Academy of Dermatology — Understand sunscreen labels](https://www.aad.org/public/everyday-care/sun-protection/shade-clothing-sunscreen/understand-sunscreen-labels)
- [DermNet — Sun protection](https://dermnetnz.org/topics/sun-protection)

General information, not medical advice.