PA++++ and PPD: What the UVA Rating Really Means
You already scan the SPF number. But right next to it sits something like PA++++, and most people have no idea what those little plus signs are counting. The plus signs are the other half of your sunscreen, and they cover a completely different problem than SPF does. SPF is about burning. PA is about aging, dark spots, and damage that reaches deeper than your skin can feel. Those plus signs come straight from a lab test with a real number behind them, and once you know the number, the label stops being a mystery.
TL;DR: The PA rating measures how well a sunscreen blocks UVA rays, the ones tied to aging and pigmentation, while SPF only measures UVB, the rays that burn. PA ranges from PA+ to PA++++, based on a lab value called PPD. Roughly, PA+ blocks about half of UVA, and each extra plus sign about doubles the protection, up to PA++++, which blocks around 94%. For everyday sun, look for PA+++ or PA++++ next to at least SPF 30. One rating without the other leaves half of the sun’s damage uncovered.
What does the PA rating mean on sunscreen?
Answer first: the PA rating tells you how much UVA protection a sunscreen gives. PA stands for Protection Grade of UVA, and it goes from PA+ (some protection) up to PA++++ (the most a label can show). The scale comes from the Japan Cosmetic Industry Association, which set the testing standard behind it [1]. Korea’s Ministry of Food and Drug Safety regulates sunscreen as a functional cosmetic and uses the same PA scale, which is why the rating shows up on nearly every Korean sunscreen.
SPF is UVB, PA is UVA (not the same ray)
Sunlight reaches your skin as two kinds of ultraviolet, and they do different damage. UVB, at a wavelength of about 290 to 320 nanometers, is the burning ray, and that’s the only thing SPF measures. UVA, at about 320 to 400 nanometers, is the longer wavelength that penetrates deeper into your skin [2]. SPF says nothing about UVA. A sunscreen can have a high SPF and still be weak against UVA, which is exactly why the PA rating exists as a separate label. The Japanese standard even requires that PA always be printed next to an SPF value, because no sunscreen protects against UVA alone [1]. If you want the SPF side in detail, we broke down SPF 30 vs 50 and what those numbers really block.
What PA++++ and PPD actually mean
Behind the plus signs is a lab value called PPD, short for persistent pigment darkening. It works like SPF, but for UVA: the test times how long protected skin takes to tan under UVA compared to bare skin [2]. A PPD of 16 means your skin can take about 16 times the UVA before it starts to darken. The Japan Cosmetic Industry Association standard turns that PPD value into the plus signs you see on the bottle [1]:
| PPD value (UVA protection factor) | Rating |
|---|---|
| 2 or more, but less than 4 | PA+ |
| 4 or more, but less than 8 | PA++ |
| 8 or more, but less than 16 | PA+++ |
| 16 or more | PA++++ |
Notice the pattern: each plus sign roughly doubles the number, so the shorthand is 2 to the power of the plus signs [2]. Translated into how much UVA is actually stopped, a PPD of 16 lets only about 1 in 16 rays through, so PA++++ blocks roughly 94% of UVA. Lab Muffin puts a PPD of 10 at about 90% blocked, and the math scales the same way from there [2].
One limit worth knowing: the plus-sign system is coarse. A product tested at PPD 20 and one tested at PPD 40 both land at PA++++, so the label cannot tell them apart. The safe way to read it is to assume a PA++++ product protects at the floor of its range, a PPD of 16, and not to expect more just because it maxed out the plus signs.
Why UVA is the aging ray you can’t feel
UVB burns, so you notice it. UVA does not, which is what makes it easy to ignore. Its longer wavelength reaches deeper, into the dermis, where your collagen and elastin sit. There it drives photoaging: wrinkles, loss of firmness, and the uneven pigmentation and dark spots that surface years later. UVA also forms free radicals that damage your skin’s proteins and DNA, which is linked to both visible aging and melanoma [2]. That’s why a strong PA rating matters even when you’re not planning to burn.
UVA is also more constant than UVB across the day and the seasons, and it passes through window glass, so it reaches you indoors and in the car too. We covered that side in our guide to Korean sunscreen for driving and window UVA.
Daily use: aim for PA+++ or higher
For everyday sun, aim for PA+++ or PA++++, paired with at least SPF 30. That combination covers both the UVB that burns and the UVA that ages. The plus signs only describe UVA, so a high PA with a low SPF, or the reverse, still leaves a gap. The simplest check is to look for an SPF and a PA rating printed together, or the words broad spectrum.
High PA ratings come from strong UVA filters, and the newer ones reach that protection while staying light enough to actually wear every day. We walk through them in our guide to the newer filters in Korean sunscreens. And for how SPF and PA fit into picking a sunscreen overall, our complete Korean sunscreen guide puts it together.
Read both numbers, not one
The PA rating is the UVA half of sun protection, and SPF can’t stand in for it. PA+ blocks about half of UVA, and each plus sign roughly doubles that, so PA++++ (a PPD of 16 or more) blocks around 94%. UVA is the ray you can’t feel, the one behind wrinkles and dark spots, and it reaches you through glass and all year round. So read both numbers. Look for PA+++ or PA++++ next to a solid SPF, and you have covered the burning and the aging at once.
FAQ
What does PA mean in sunscreen?
PA stands for Protection Grade of UVA. It’s a rating from PA+ to PA++++ that tells you how well a sunscreen blocks UVA rays, the ones linked to aging and dark spots. It was developed in Japan and is used across Korea and much of Asia, which is why it appears on most Korean sunscreens. Unlike SPF, which only covers UVB, PA covers UVA.
What does PA++++ mean?
PA++++ is the highest UVA rating a label can show. It matches a PPD (persistent pigment darkening) value of 16 or more, which works out to blocking roughly 94% of UVA rays. Each plus sign about doubles the protection, so PA++++ is the strongest UVA defense on the scale.
Is PA the same as SPF?
No. SPF measures protection from UVB, the rays that cause sunburn. PA measures protection from UVA, the rays that cause aging and pigmentation. They’re different wavelengths and different ratings, so you want both. A high SPF on its own doesn’t guarantee strong UVA protection.
What PA rating should I use daily?
For everyday sun, look for PA+++ or PA++++ paired with at least SPF 30. That covers both the UVB that burns and the UVA that ages your skin. If a sunscreen shows a high SPF but no PA rating and no broad spectrum label, you can’t be sure it protects you from UVA.
Sources
PA rating, PPD, and UVA (checked 2026-07-18):
[1] Notifications on SPF, UVA Protection Grade (PA), and Water Resistance, Japan Cosmetic Industry Association (official UVA protection factor to PA grade table: “2 or more but less than 4 = PA+”, “4 or more but less than 8 = PA++”, “8 or more but less than 16 = PA+++”, “16 or more = PA++++”; measured by the persistent pigment darkening method per ISO 24442; PA must be labeled together with an SPF value because no sunscreen protects against UVA alone): link
[2] Why you should protect your skin from UVA, Lab Muffin Beauty Science (PPD is “persistent pigment darkening,” the equivalent of SPF for UVA; PA+ ≈ PPD 2-4, PA++ ≈ 4-8, PA+++ ≈ 8-16, PA++++ ≈ 16+, conversion is 2 to the power of the plus signs; PPD 10 blocks about 90% of UVA; UVA is 320-400 nm, penetrates deeper than UVB, and forms free radicals that cause wrinkles, old-looking skin, and melanoma): link
