What Is The Meaning Of Pa: Expert Guide

You’ve seen “PA+++” or “PA++++” on labels but aren’t sure what it really guarantees—or how it compares with SPF. This guide translates the jargon into decisions you can actually use when specifying or buying sunscreen for your brand.

PA means “Protection Grade of UVA.” It’s a UVA rating derived from PPD/UVAPF testing: PA+ (PPD ≥2), PA++ (≥4), PA+++ (≥8), PA++++ (≥16). PA indicates how well a product protects against UVA (photo-aging, pigmentation), while SPF covers UVB (sunburn). For complete coverage, use broad-spectrum SPF with an appropriate PA level, then reapply as directed.

What does PA mean on sunscreen?

PA is a label telling you how strongly a sunscreen protects against UVA. It’s expressed as plus signs, where more “+” means higher UVA protection. The scale is derived from PPD/UVAPF testing of how much UVA it takes to darken protected skin versus unprotected skin. It complements—but does not replace—SPF.

Is PA a UVA-only score?

Yes. PA targets UVA (320–400 nm), the rays linked to photo-aging, uneven tone, and deep-layer damage; SPF reflects UVB burn risk. Because both ray types harm skin, you need both PA and SPF (broad-spectrum).

Where did PA come from?

Japan pioneered PA to communicate UVA strength to consumers. The Japan Cosmetic Industry Association (JCIA) ties PA grades to UVAPF/PPD results and, since 2013, recognizes PA++++ as the highest grade.

Will you see PA on every market’s labels?

No. PA is common across Japan/Korea/parts of APAC. The EU uses a UVA-in-a-circle logo; the UK may show Boots UVA stars; the US uses the term Broad Spectrum (critical wavelength ≥370 nm).

PA is a UVA grade built from in-vivo pigment darkening tests; SPF remains essential for UVB. Labels differ by region, so don’t assume PA will appear on every product.

How is PA measured and who sets the standard?

PA grades come from UVAPF/PPD testing, historically via ISO 24442. The JCIA formalized the grade cut-offs and updated them when ISO updated the method (e.g., 2012/2022 changes). PA+ to PA++++ correspond to rising UVAPF/PPD ranges.

What is PPD/UVAPF in plain English?

It’s the ratio of UVA dose needed to produce persistent pigment darkening on protected skin versus unprotected skin. A PPD of 16 (the threshold for PA++++) means protected skin can tolerate 16× the UVA before tanning compared with bare skin.

What changed in the latest standards?

ISO/JCIA updates refined how subjects are chosen (e.g., using ITA° rather than Fitzpatrick skin typing) and clarified MPPDD definitions and reference samples. The PA expression still maps to UVAPF integer values.

Who actually “decides” your PA grade?

Manufacturers test to ISO 24442 (or equivalent) and then apply the JCIA PA expression rules to label PA+, ++, +++, or ++++ alongside the product’s SPF. Audits may be market-driven rather than legal, but major brands follow the standard.

PA grades and their measured basis

PA is standardized via ISO 24442 methodology; the JCIA maps results to the familiar “+” grades, with PA++++ at PPD ≥16.

Which PA level should you choose by skin tone, UV index, and lifestyle?

Use UV Index + exposure pattern + skin tone goals to pick PA. Indoors near windows? UVA still penetrates glass. For daily city life, PA+++ is usually prudent; for high-UV travel or outdoor work, PA++++ with high SPF is wiser—regardless of skin tone—plus hats/shade and reapplication.

How does the UV Index change the target PA?

As UVI rises (3–5 “moderate”, 6–7 “high”, 8–10 “very high”, 11+ “extreme”), the margin for error shrinks. At UVI ≥6, recommend PA++++ with SPF 50 and strict reapplication.

Do deeper skin tones need high PA?

Yes—melanin reduces burning but UVA drives photo-aging and uneven pigmentation in all tones. High-PA products help manage melasma/post-inflammatory hyperpigmentation risk, especially in sunny or year-round UV environments. (General dermatology consensus; pair PA with high SPF.)

Indoors or driving—still need PA?

UVA penetrates window glass, so for desk work by a window and driving commutes, choose PA+++ to PA++++ daily, even if you rarely burn.

Quick selector by UVI, lifestyle, and skin tone

*UVI references follow WHO/EPA guidance;

UVI and exposure drive PA choice. For most daily needs PA+++, for high-UV/outdoor PA++++, always paired with SPF and reapplication.

How is PA different from SPF—and do you need both?

SPF quantifies UVB burn protection; PA reflects UVA protection. You want a product that is broad-spectrum: in the US, that means critical wavelength ≥370 nm; in the EU, UVA protection must be at least 1/3 of SPF and is shown via the UVA-in-a-circle logo.

What exactly does SPF measure?

SPF compares the UVB dose to cause erythema on protected versus unprotected skin under standardized conditions. It does not describe UVA. High SPF does not promise high UVA—hence the need for PA/broad-spectrum verification.

What do “Broad Spectrum,” the UVA-circle, and stars mean?

US Broad Spectrum = passes the critical-wavelength test (≥370 nm). EU = UVA-circle means UVA ≥ 1/3 SPF, plus labeling guidance. UK Boots stars compare UVA to UVB balance (0–5★).

How do I combine SPF and PA in specs?

For daily wear, SPF 50 PA+++ is a strong baseline. For high UV, SPF 50+ PA++++. In all cases, ensure the product passes regional broad-spectrum criteria and communicates the region-appropriate UVA label (PA/UVA-circle/stars).

Label systems at a glance

SPF ≠ PA. You need both, expressed via region-specific systems. Verify broad-spectrum compliance before focusing on marketing claims.

Is PA++++ always better, and what are the trade-offs ?

Higher PA can help, especially at high UVI and for pigment-prone skin, but it isn’t magic. Real-world protection depends on application amount (2 mg/cm²), even coverage, photostability, water/sweat, and reapplication. Chasing PA++++ may add white cast, thicker textures, or cost without fixing usage gaps.

Are there diminishing returns for low-UV lifestyles?

Yes. If you’re mostly indoors away from windows, consistent use of a pleasant SPF 50 / PA+++ you’ll actually apply and reapply beats a heavy PA++++ you skip. Fit and adherence matter more than one more “+”.

Does PA++++ always look/feel better?

Not necessarily. Achieving very high UVA can require more zinc oxide (possible white cast) or complex filter/stabilizer systems that alter feel. Coated pigments, film formers, and modern esters help—but sample and iterate if makeup-compatibility is key.

Isn’t “more +” automatically safer?

Only if tested, stable, and used correctly. Remember: no sunscreen blocks 100% and applying less than the tested 2 mg/cm² dramatically reduces protection. Reapplication and hats/shade still matter.

Aim for high but wearable protection. Usage and stability often trump an extra plus sign.

Do mineral vs chemical filters affect PA performance and stability?

Yes. UVA1 (340–400 nm) coverage depends on the filter set. Zinc oxide and avobenzone are core UVA workhorses; advanced EU filters (bemotrizinol/Tinosorb S, bisoctrizole/MBBT) strengthen coverage but aren’t US OTC actives. Photostability and film formation determine whether labeled PA holds up on skin.

Which filters actually cover UVA1?

• Avobenzone and zinc oxide cover deep UVA1;
• Titanium dioxide skews UVB/UVA2;
• Tinosorb S (bemotrizinol) and MBBT (bisoctrizole) add very broad UVA/UVB in markets where allowed.

Combine filters plus stabilizers (e.g., octocrylene/photostabilizers) to preserve spectra. (Regulatory availability varies.)

Is avobenzone stable?

Alone it can photo-degrade; modern formulas utilize stabilizers and encapsulation. Zinc oxide is inherently stable but can shift aesthetics; coatings and dispersion technology improve performance.

What if I’m formulating for the US versus EU?

US OTC recognizes specific actives (e.g., avobenzone, zinc oxide, titanium dioxide). Many EU/Japan filters (e.g., Tinosorb S/M, MBBT) are not in the current US OTC monograph; plan different regional variants or seek approved NDAs.

Common UVA drivers and regional notes

To hit a target PA that wears beautifully, pair UVA1 drivers with stabilizers/film formers and tune pigments/emollients by region.

Which regions use PA versus UVA circle/Boots star—how do labels compare?

PA dominates Japan/Korea/APAC. The EU simplifies with a UVA-in-a-circle logo (UVA ≥ 1/3 of SPF). The UK often shows Boots UVA stars (0–5★) as a retailer system. The US mandates “Broad Spectrum” via critical wavelength (≥370 nm).

Why did Europe pick the UVA-circle?

Europe adopted the UVA-in-a-circle logo to standardize UVA/UVB balance and simplify labels across languages. It signals UVA protection at least one-third of SPF, aligns with critical-wavelength criteria, and curbs misleading “sunblock” or absolute claims. The scheme improves clarity, enforces a UVA floor, and supports consistent testing, warnings, and reapplication instructions.

What do Boots stars really tell you?

Boots UVA stars indicate how balanced a product’s UVA protection is relative to its UVB protection, not the absolute strength. A 4–5 star rating suggests strong balance, useful for everyday wear. Still check SPF for burn protection, plus texture, photostability, and application amount to ensure real-world performance in daily conditions.

How does “Broad Spectrum” differ?

In the US, “Broad Spectrum” is a pass/fail based on spectral coverage (critical wavelength). It says nothing about PPD, so high SPF + Broad Spectrum may still vary in UVA strength versus PA.

Label ecosystems differ. If you export, map claims to regional rules and keep internal test packages ready.

How to build a daily routine: PA with antioxidants, reapplication, and makeup?

Pair SPF 50 + appropriate PA with antioxidants and consistent reapplication. Apply 2 mg/cm² (about 1/3–1/2 tsp face/neck), wait to set, then use makeup. Reapply every 2 hours (or after water/sweat) per label. Choose textures that make this feasible for your customer.

What’s the ideal AM order—and how much?

Cleanser → lightweight antioxidants/serum → sunscreen (2 mg/cm²) → primer/makeup. Under-applying dramatically cuts protection; half the dose can slash protection by up to ~⅔. Use measured pumps or a dosing spoon to standardize applications.

How do I reapply over makeup?

Use sticks, cushions, mists, or powders designed for reapplication. Aim for even coverage on high points (forehead, nose, cheeks). For outdoor days, re-up at lunch and mid-afternoon; on beach/field days, follow the 40/80-minute water-resistance cues.

Do antioxidants actually matter with PA?

Yes. Antioxidants help buffer residual ROS that slip through even high-PA films. They don’t replace sunscreen but support long-term tone and firmness goals when paired with reliable UVA/UVB coverage.

Practical reapplication planner

Protection = dose × reapplication × coverage. Build products and instructions customers can follow—not just labels they can’t interpret.

Conclusion

PA translates lab-measured UVA protection into a simple “+” scale. It complements SPF (UVB) and sits inside different regional ecosystems (PA, UVA-circle, stars, Broad Spectrum). For daily city life, SPF 50 / PA+++ is a realistic baseline; for high UV or pigment-prone users, step up to PA++++ and ensure reapplication. Filters and aesthetics matter: combine UVA1 drivers (zinc oxide, avobenzone, or advanced EU filters) with stabilizers and textures that customers enjoy—otherwise compliance fails.

Build with Zerun Cosmetic: We formulate region-specific sunscreens (US/EU/APAC) and can customize SPF/PA targets, filter systems, photo-stability, and packaging (airless, UV-safe) with full test support. Need makeup-friendly finishes or sport-grade 80-minute water resistance? We’ll prototype, stability-test, and iterate until it’s right. Request free design & samples to launch a compliant, high-retention sunscreen line fast.