GUIDE
Modern UV filters, explained
Most of what makes a sunscreen feel light, look invisible and still protect properly comes down to which UV filters it uses. Here is what the modern ones actually do.
Published 21 September 2026 · HourGlow
Why filters matter more than SPF alone
An SPF number tells you about UVB protection measured in a lab. It says nothing about which molecules produced that number, how evenly they cover the UVA range, or whether they survive a day in the sun. Two sunscreens can both be SPF 50+ and behave completely differently on skin.
The filters do three jobs. They absorb UV across a particular band of wavelengths. They stay intact while doing it — this is photostability, and an unstable filter stops protecting you as the hours pass. And they determine texture, because the amount of filter needed to hit a given SPF varies enormously between molecules.
Older filters versus newer ones
Older organic filters such as avobenzone and octinoxate work, but have real limitations. Avobenzone is the classic UVA filter and degrades meaningfully under sunlight unless something else stabilises it. Because older filters absorb less efficiently per gram, formulas need more of them, which is a large part of why traditional sunscreens felt heavy and greasy.
Newer filters are bigger molecules that absorb far more strongly and hold up far better under light. Less material is needed, so the formula can be lighter. That is the whole reason a modern SPF 50+ can feel like water instead of paint.
The three filters in HourGlow
Bemotrizinol
Tinosorb S. Broad spectrum, absorbs across both UVB and UVA, and stabilises other filters. FDA-approved in June 2026 — the first new US sunscreen filter in 27 years.
DHHB
Uvinul A Plus. A dedicated UVA filter peaking at 354 nm, in the range avobenzone covers but with far better photostability.
Ethylhexyl Triazone
Uvinul T 150. A UVB specialist peaking at 314 nm, used to build high SPF without heaviness.
UVB, UVA and what the ratings mean
| UVB — 280 to 320 nm | Higher energy. The main cause of sunburn. This is what the SPF number measures. |
|---|---|
| UVA — 320 to 400 nm | Penetrates deeper into skin. Associated with photoageing and pigmentation, and passes through window glass. Measured by the PA rating. |
| SPF 50+ | The top of the UVB scale under standardised testing. |
| PA++++ | The highest grade in the PA system for UVA protection. |
A sunscreen needs both. An SPF 50+ product with weak UVA coverage lets you stay out without burning while the ageing wavelengths keep working — arguably worse than no sunscreen at all, because the burn that would have sent you indoors never arrives.
Why this matters in India
UV index readings across much of India sit high for most of the year, and UVA levels stay relatively constant across seasons and cloud cover. Humidity is the other factor: a filter system that needs heavy emollients to stay stable will feel unbearable in a Delhi summer, which is the real reason so many people stop wearing sunscreen by March.
Lighter, more efficient filters are not a marketing detail here. They are the difference between a sunscreen you actually wear every day and one that sits in a drawer.
Common questions
What are new-generation UV filters?
Organic sunscreen actives developed from the late 1990s onwards — bemotrizinol, DHHB, ethylhexyl triazone and others. They are large, highly photostable molecules that absorb strongly across UVB, UVA or both, which is why modern sunscreens reach high SPF and PA ratings in much lighter textures.
Are modern UV filters available in India?
Yes. Bemotrizinol, DHHB and ethylhexyl triazone are all permitted in cosmetic sunscreens in India, as they are in the EU, Japan and Australia.
Why were these unavailable in the United States for so long?
The US regulates sunscreen as an over-the-counter drug rather than a cosmetic, so a new filter needs full FDA approval instead of a cosmetic listing. Bemotrizinol was approved in June 2026 — the first new sunscreen active approved in the US since 1999 — despite having been used in Europe since 2000.
HourGlow Glow Shield Sunscreen is an SPF 50+ PA++++ daily sunscreen built on these three filters, with niacinamide and vitamin C. 50 ml, Rs 999.
General information only. This page explains how UV filters work; it is not medical advice. Sunscreen performance depends on applying enough product and reapplying. For a specific skin concern, speak to a dermatologist.