UVA star rating and PA+: what they measure

Claim status: UVA rating labels

The UVA Star Rating and the PA system are consumer-facing ways of communicating aspects of laboratory UVA testing. They are not complete accounts of sunscreen performance. In particular, neither replaces the labelled SPF, and neither alone establishes how a product will perform after application, sweating, swimming, rubbing or using too little product.

The UK cosmetic claims framework requires claims to be supported and not misleading. That requirement does not make either the star system or PA grades compulsory label features. A symbol can therefore have a defined meaning under its own scheme while remaining voluntary on UK packaging.

SPF principally concerns protection against UVB-related sunburn. UVA reaches deeper into skin and is associated with tanning, persistent pigment darkening and photoageing. The systems discussed here concern UVA, but they do so in different ways. Reading either mark properly starts with recognising that it answers a limited question rather than providing a universal quality score.

What the UVA Star Rating measures

The UVA Star Rating is a proportionality system. In simplified terms, it compares a product’s measured UVA protection factor with its labelled SPF. The resulting ratio is placed into a star band. A higher star result indicates that the UVA protection is closer, proportionately, to the product’s UVB-related SPF performance.

This is not an absolute ladder of UVA strength. A five-star rating does not state the product’s standalone UVA protection factor. Two products can carry five stars while having different SPFs and different measured UVA protection factors. The common result means that both meet the scheme’s relevant proportionality band, not that their UVA results are identical.

The star symbol is useful for the particular issue it addresses: balance between UVA and SPF performance. It does not identify the formula’s ingredients, establish water resistance, show whether a product suits a particular skin condition, or report every wavelength-specific result. It also cannot tell a reader whether another product with a different label system is stronger in every relevant respect.

European sunscreen guidance has used both a minimum UVA protection level relative to SPF and a critical-wavelength criterion. That wider approach helps explain the usefulness of a ratio-based communication system. However, the star scale itself remains a defined voluntary scheme. The graphic communicates one comparison and should not be treated as a complete technical report.

What PA+ to PA++++ measures

PA means protection grade of UVA. The system defined by the Japan Cosmetic Industry Association places measured UVA protection into plus-sign bands. It is associated with the persistent pigment darkening method, which assesses a delayed skin-darkening response used in UVA evaluation.

The published bands are PA+ for a UVA protection factor from 2 to less than 4, PA++ for 4 to less than 8, PA+++ for 8 to less than 16, and PA++++ for 16 or more. These are bands of measured UVA protection. They are therefore different from a star rating, which concerns the ratio of UVA protection to labelled SPF.

A PA grade does not disclose SPF. It cannot, by itself, show the relationship between UVA protection and the product’s UVB-related protection. Nor does it identify a product’s testing protocol in full, its water-resistance performance, its ingredients or whether it is appropriate for an individual user.

The compact appearance of plus signs can encourage an over-simple reading. PA++++ is the highest PA band, but it is not a general verdict that one sunscreen is superior to another in every respect. It is a defined classification of one measured UVA result. Its meaning depends on retaining the context of the PA scheme rather than treating the marks as a universal hierarchy.

Why a UK label may show either system, both or neither

UK cosmetic labelling does not require all sunscreens to display a UVA Star Rating or a PA grade. Subject to the rules governing claims, a package may use a recognised communication system where the underlying evidence supports it. It may instead use another substantiated presentation, or display neither of these symbols.

The legal framework and the communication schemes should not be merged. UK rules address matters including safety, responsible persons, product information and labelling. The common criteria for cosmetic claims concern matters such as evidential support and non-misleading presentation. A star graphic or PA mark is a further choice about how a technical result is presented to consumers.

Packaging may also be designed for more than one market. PA is particularly associated with the Japanese system and may be visible on packaging used beyond Japan. Its presence on a UK package does not create a special UK legal category. Equally, the presence of a star rating does not establish that PA testing was undertaken but omitted.

Labels have limited space and are not expected to contain every element of a product’s compliance record. The absence of a voluntary icon says only that that icon is absent. It cannot, without further evidence, establish that no UVA assessment took place or that the product lacks an appropriate level of UVA protection.

Decision rule when neither symbol appears

A package with neither stars nor PA signs presents an information limit, not a negative verdict. Neither system is a general compulsory UK label feature. The most that can be said from the blank space is that neither particular voluntary shorthand is displayed.

The words “broad spectrum” do not automatically fill the information gap. Their practical meaning depends on the jurisdiction, stated standard and evidence behind the claim. Standing alone, the phrase does not identify a PA band, a star ratio, a critical wavelength or a particular UVA protection factor.

The Advertising Standards Authority expects objective advertising claims to be substantiated. That is a constraint on what can be asserted in advertising. It is not a rule requiring every technical test result to be printed on a product’s front label. The question of supporting evidence and the question of consumer-facing disclosure are connected but separate.

Why no conversion table is valid

Five stars and four plus signs can look like neighbouring scales, but no reliable conversion table follows. The star system begins with a ratio. PA begins with an absolute UVA protection band. Each system therefore describes a different dimension of test results.

Consider the mathematics without referring to any product. Two formulas could have the same UVA protection factor but different SPFs. Their UVA-to-SPF ratios would differ, so their possible star outcomes could differ even though their UVA factors matched. Conversely, two formulas with different UVA protection factors and SPFs could have the same ratio and therefore reach the same star band while potentially falling into different PA bands.

Laboratory methods and application conditions matter too. A consumer symbol does not reproduce the complete protocol, the complete result, possible variation in testing, or every property of the finished formula. It provides a defined summary. Treating it as a universal measure introduces precision that the mark does not claim to provide.

Neither symbol answers separate questions about UV filters, formula type, ingredient origin, environmental effects, skin compatibility or water resistance. Those matters require their own definitions and evidence. An ultraviolet performance classification should not be extended into a judgement about the whole product.

Terms that sound similar but are not equivalent

“UVA protection” is a broad description. “UVA protection factor” is a measured quantity under a stated method. PA is a banding system based on UVA measurement, while UVA stars are a proportionality scale. These terms belong to the same subject area but are not interchangeable.

“Broad spectrum” is also a general expression rather than a single global technical label. Its significance depends on the standard, jurisdiction and claim context. It should not be read as a hidden PA grade or an implied star rating unless the relevant testing basis is made clear.

Critical wavelength is another distinct concept. It describes the wavelength below which a specified proportion of ultraviolet absorbance occurs. In European sunscreen guidance, it appears alongside a minimum UVA protection ratio. It is neither a PA grade nor a number of stars, and knowing it does not by itself generate either consumer mark.

The phrase “UVA compliant” needs similar care. Detached from a named requirement, it does not say what test, threshold or communication standard is meant. A meaningful assessment asks: compliant with which rule or scheme? This avoids both common errors: assuming that an icon proves every desirable property, and assuming that no icon proves the absence of testing or protection.

Limits of this reference

This reference explains the meaning and limits of UVA Star Ratings and PA grades in a UK context. It does not assess named sunscreens, interpret a specific package, rank products, or determine whether a particular claim has sufficient substantiation. Those questions require the exact claim, its presentation and the supporting evidence.

It does not provide individual advice on sun exposure, application, reapplication, swimming, sport, travel, infant use or management of a skin condition. It also does not address permitted UV filters, water-resistance claims, ingredient safety or environmental assertions. Those subjects involve separate regulatory, clinical or environmental questions.

The PA bands quoted here are those defined by the Japan Cosmetic Industry Association. The explanation of stars concerns the ratio-based structure of that scheme. Standards, guidance and packaging can change, and packaging may serve several jurisdictions. Where a question concerns a current legal duty rather than the meaning of a symbol, current UK legislation and regulator guidance are the appropriate controlling sources.

Most importantly, the absence of stars or PA is not a laboratory result. It is only the absence of these particular voluntary displays. No conclusion about a sunscreen’s UVA performance should be drawn from that fact alone.