Sunscreen Testing & Ratings — What We Can Tell You
What does SPF mean, and how is it measured?
Sun Protection Factor (SPF) is a number that indicates how well a sunscreen filters ultraviolet B (UVB) rays — the rays primarily responsible for sunburn. The higher the SPF number, the greater the UVB filtration. SPF is determined through standardized in vitro (lab) or in vivo testing methods established by regulatory bodies such as the U.S. FDA. An SPF 50 product, for example, is formulated to filter approximately 98% of UVB rays under controlled test conditions.
SPF does not measure UVA protection. UVA rays penetrate more deeply and are evaluated on a separate scale.
What is the PA rating, and how does it differ from SPF?
PA (Protection Grade of UVA) is a UVA protection grading system developed in Japan and widely used across Asia. It is based on the Persistent Pigment Darkening (PPD) method and is expressed as:
- PA+ — some UVA protection (PPD 2–3)
- PA++ — moderate UVA protection (PPD 4–7)
- PA+++ — high UVA protection (PPD 8–15)
- PA++++ — extremely high UVA protection (PPD 16 or above)
PA++++ is the highest grade on this scale. It is not equivalent to any specific SPF number — they measure entirely different types of UV radiation using different methods.
How is a PA++++ rating verified?
PA++++ claims are supported by PPD or similar UVA testing conducted in a laboratory. Reputable manufacturers submit their formulations to accredited third-party labs that follow established test protocols (such as JCIA guidelines or ISO 24442). The resulting test report documents the measured PPD value that determines the PA grade assigned to the product.
[Merchant note: If your supplier has provided third-party test reports or certificates of analysis for your PA++++ products, add a specific statement here — for example: "Our [Product Name] has been tested by [Lab Name] and achieved a PPD value of [X], confirming its PA++++ rating. Test documentation is available upon request." Only include this after verifying the documentation with your supplier.]
Are lab names or test reports available?
Test documentation practices vary by manufacturer. Some provide full third-party lab reports; others share certificates of analysis or summary data.
[Merchant note: List here which products have documentation available and how customers can request it — for example, by emailing your support address. If you are awaiting documentation from your supplier, you may note it is under review and will be posted when confirmed.]
Does PA++++ mean the product is tested to a higher standard than PA+++?
Yes, within the PA grading system, PA++++ requires a measured PPD value of 16 or higher, while PA+++ requires PPD 8–15. A higher grade indicates a product that demonstrated greater UVA protection under standardized test conditions — not simply a marketing label.
What testing methods are commonly used for UVA ratings?
Two widely recognized methods are:
- PPD (Persistent Pigment Darkening): Measures UVA-induced skin darkening and is used to calculate PA grades and some UVA Protection Factor (UVAPF) values.
- UVAPF (UVA Protection Factor): A numerical value sometimes shown alongside or instead of PA grades, depending on the market and regulatory framework.
Both methods are conducted under controlled lab conditions. The specific protocol used can affect the result, which is why PA ratings from different markets may be assessed differently.
What should I look for to feel confident in a sunscreen's protection claims?
General things worth looking for:
- SPF and PA ratings tested to recognized standards (FDA, ISO, JCIA)
- Third-party (not just manufacturer) lab testing
- Ingredients listed in compliance with local regulations (e.g., FDA-approved UV filters in the U.S.)
- Manufacturer transparency about test documentation
We are not dermatologists and cannot recommend which product is right for your skin. For personal skin health guidance, please consult a licensed dermatologist.
Where can I find more information about your specific products?
Each product page includes its SPF and PA rating, ingredient list, and usage directions. If you have questions about a specific product's test background, contact us here — we'll connect you with the information we have available from our supplier.