UVA, UVB and broad spectrum: decoding sunscreen labels

Reader Question: What protection information should I look for besides SPF?

When selecting a daily sunscreen, looking at the Sun Protection Factor (SPF) is only the first step. To ensure robust daily protection, you should look for the phrase broad spectrum on the label, verify whether the formula is water resistant (for 40 or 80 minutes), and check the active ingredients to see whether it uses physical or chemical filters 123. Dermatologists recommend choosing a broad-spectrum, water-resistant formula with an SPF of 30 or higher 24.

For related reading, explore our beauty guides and sun-protection collection.

Different ultraviolet bands

Solar radiation reaching the earth includes different bands of ultraviolet light that affect the skin in distinct ways:

• Ultraviolet A (UVA) rays: Often referred to as "ageing" rays, UVA rays contribute to premature skin ageing, including wrinkles, loss of firmness, and age spots, as well as skin cancer 6.
• Ultraviolet B (UVB) rays: Referred to as "burning" rays, AAD describes UVB as burning rays and explains broad-spectrum protection against UVA and UVB 6.

In addition to ultraviolet radiation, visible light can also impact the skin 7. Tinted sunscreens that contain iron oxide offer protection against visible light 7. This is particularly beneficial for deeper skin tones, where visible light and UV exposure can trigger or worsen hyperpigmentation and melasma, while also preventing the chalky white cast sometimes left by un-tinted mineral filters 78. For tailored guidance, explore our guide on choosing sunscreen for dark skin without skipping protection related guide.

SPF limits

The Sun Protection Factor (SPF) is an official testing metric that indicates how effectively a sunscreen filters out UVB rays 46:

• SPF 15 filters out approximately 93% of UVB rays 4.
• SPF 30 filters out approximately 97% of UVB rays 4.

Dermatologists recommend choosing an SPF of 30 or higher for daily use 4. However, it is vital to recognise that no sunscreen can filter out 100% of UVB light 4. Because no product provides absolute blockade, sun protection should always be paired with sensible habits such as seeking shade and wearing protective clothing, wide-brimmed hats, and UV-blocking sunglasses 4. For details on applying sufficient amounts, see our advice on how much sunscreen is enough for even coverage related guide.

Broad-spectrum wording

The AAD guide explains broad spectrum in the context of US FDA sunscreen labelling 1. It signifies that the product has passed standardised testing showing it protects against both UVA and UVB radiation 16. Selecting a product labelled broad spectrum describes protection against both burning and long-term skin ageing 6.

Label wording also specifies how a formula handles moisture and active protection:

• Water resistance: The US FDA no longer permits sunscreens to be labelled as "waterproof" or "sweatproof", as water eventually washes sunscreen off the skin 2. Instead, labels may claim water resistant, which indicates the formula remains effective for either 40 minutes or 80 minutes in water or during sweating 9.
• Reapplication rules: Even when staying dry, sunscreen must be reapplied at least every 2 hours 10. AAD advises reapplying after towelling, when sweating and after being in water; follow the exact product directions alongside its water-resistance designation 910.
• Active ingredients: Active filters fall into physical (mineral) types (zinc oxide and titanium dioxide, which absorb and reflect UV rays and are recommended for sensitive skin), chemical types (non-mineral filters that absorb UV rays), or hybrid combinations 311.

Regional label symbols

The US terms in the AAD guide should not be treated as a decoder for every imported pack. If your product uses another mark or rating, ask the maker what that exact label means; do not assume a similar-looking symbol is equivalent.

Verify intended market

When purchasing imported sunscreens, always inspect the product packaging to confirm that the protection claims align with established testing standards 115. Ensure that the label explicitly states "Broad Spectrum", displays an SPF of 30 or higher, specifies water-resistance limits where relevant, and provides clear active ingredient listing 2415.

Sunscreen Label Decoder Worksheet

Use this practical label decoder checklist to evaluate sunscreen packaging against official testing standards before purchasing.