SPF, PA, broad-spectrum: How to read a sunscreen label

SPF 50, PA++++, broad-spectrum, non-comedogenic... Sunscreen labels can sometimes seem like an indecipherable code. However, each of these terms provides information about a specific aspect of protection, and knowing how to read them helps you choose a product that’s truly right for your skin.

Good sun protection isn't just about the SPF—it must protect against both UVB and UVA rays. Here's how to read a label, item by item.

UVA, UVB: Two Types of Radiation, Two Effects

The sunlight that reaches the skin consists of two types of ultraviolet rays. UVB rays, which are absorbed by the superficial layers of the skin, are responsible for sunburn (B for burn) and vary depending on the season and time of day. UVA rays, which have a longer wavelength, penetrate deeper into the dermis (A for age) and play a major role in skin aging. Present year-round, they pass through clouds and glass.

Both contribute to skin damage, ranging from oxidative stress to pigmentation spots and wrinkles. Effective protection must therefore cover both types of radiation, not just one of them.

SPF: Protection Against UVB Rays

SPF (Sun Protection Factor) measures protection against UVB rays, which primarily prevent sunburn. An SPF 30 filters out about 97% of UVB rays, while an SPF 50 filters out about 98%. The label “SPF 50+” indicates the very high protection category, reserved for products with an SPF higher than 50.

Key point: SPF only provides information about UVB rays. Two sunscreens with the same SPF may offer very different levels of UVA protection, which can have a real impact on photoaging-related damage. That is why SPF alone is not enough to ensure comprehensive protection.

SPF and broad-spectrum: protection against UVA rays

There are several ways to assess UVA protection. The PA system, used primarily in Asia, rates UVA protection using "+" symbols, ranging from PA+ (low protection) to PA++++ (very high protection). In Europe, the “UVA” logo enclosed in a circle indicates that UVA protection is at least one-third of the listed SPF.

The term "broad spectrum" indicates that the product protects against both UVA and UVB rays. This is the most important factor to consider: combining a high SPF with high UVA protection—indicated by PA++++ or the UVA logo—ensures much more comprehensive coverage.

Other Terms You Should Know

Other information is included on the label. A "+" sign after an SPF number means the value is higher than the number shown. The term "water-resistant" indicates that protection is maintained after a specified amount of time spent in the water. "Non-comedogenic" indicates a formula designed not to clog pores. Finally, the texture (fluid, gel, matte finish) affects comfort and, therefore, the evenness of application, which determines the product’s actual effectiveness.

How to Choose and Apply Sunscreen Properly

In practice, choose a broad-spectrum product with an SPF of at least 30—ideally 50+—and high UVA protection. Apply a sufficient amount, as applying too little significantly reduces the actual level of protection. Reapply every two hours, as well as after swimming or heavy sweating.

Consistency is key: applying sunscreen daily is the most well-documented way to reduce sun-induced skin aging, even on cloudy days.

PERS SPF 50+ Gel Sunscreen

The PERS SPF 50+ Gel Sunscreen ticks all the boxes: SPF 50+ for very high protection against UVB rays, a PA++++ rating for maximum UVA protection, and broad-spectrum protection against both UVA and UVB rays. It’s enriched with vitamin E, an antioxidant that enhances protection against oxidative stress. Its transparent, non-sticky texture with a matte finish—that leaves no white residue—is designed for everyday use and blends seamlessly under makeup.

Key Takeaways

Reading a sunscreen label means checking two things: the SPF, which indicates protection against UVB rays and sunburn, and UVA protection, indicated by the PA rating, the UVA logo, or the term “broad spectrum,” which primarily addresses skin aging. Effective protection combines a high SPF with high UVA protection, is applied in sufficient quantity, and is reapplied regularly. By understanding these terms, you can choose truly comprehensive protection, day after day.

Scientific Sources