Broad spectrum: what the phrase requires, and where it requires nothing at all

A phrase that travels badly

Broad spectrum is one of the few pieces of sun protection vocabulary that means something precise in one jurisdiction and something looser in another. Because packaging, advertising copy and retail listings move across borders more easily than regulatory definitions do, the phrase turns up on British shelves carrying an authority it does not have here.

The idea behind it is sound and worth stating plainly. A product can achieve a high sun protection factor while offering comparatively little protection against the longer ultraviolet wavelengths, because the factor is measured against reddening and reddening is driven mainly by the shorter wavelengths. Broad spectrum is the industry's shorthand for a product that does not have that shape.

Where the phrase is defined

In the United States sunscreens are regulated as over the counter drugs rather than as cosmetics, and the labelling rules are correspondingly prescriptive. Broad spectrum is a term a product may use only if it passes a specified test, and the criterion is a critical wavelength of at least 370 nanometres.

Critical wavelength is the wavelength below which ninety per cent of a product's ultraviolet absorbance falls. A higher value means the absorbance extends further into the long wavelength end of the ultraviolet band. Setting the bar at 370 nanometres is a way of requiring that a product's protection does not stop where the reddening effect stops.

The consequence for a reader is that broad spectrum on a product marketed under United States rules is a claim with a defined test behind it, and one that the labelling rules tie to specific accompanying statements.

What the phrase rests on in the United Kingdom

In the United Kingdom a sun protection product is a cosmetic. The cosmetics regime does not define broad spectrum, does not set a test for it and does not restrict its use to products meeting a stated threshold.

That does not make the phrase unregulated. It means it is regulated generally rather than specifically. A claim on a cosmetic product must comply with the common criteria for cosmetic claims, which require among other things that a claim is truthful, that it is supported by the evidence held, and that it allows the average consumer to make an informed decision. Advertising is separately subject to the United Kingdom advertising codes, which require that claims are not misleading and that objective claims can be substantiated.

So a manufacturer using the phrase in the United Kingdom needs evidence in its product information file that supports it. What it does not have is a single number that defines what supporting it means. In practice the evidence relied on is the same body of ultraviolet A testing that sits behind the UVA circle, and the circle is the mark that carries a defined threshold on a British pack.

Why the circle does the work here

The European Commission recommendation on sunscreen efficacy claims takes a different approach from a defined marketing term. Rather than regulating a phrase, it recommends a performance relationship: ultraviolet A protection of at least a third of the labelled sun protection factor, together with a critical wavelength of at least 370 nanometres, communicated by the circled mark.

The result is that the British pack carries a symbol where the American pack carries a phrase, and the symbol is arguably the more informative of the two, because its threshold moves with the labelled factor rather than sitting at a fixed line. What the symbol does not do is tell a reader what it means, which is a communication problem rather than a measurement one.

Reading the phrase on a British pack

If you see broad spectrum on a product sold in the United Kingdom, the questions worth asking in order are simple.

Does the pack also carry the circled ultraviolet A mark? If so, the product meets the recommended relationship between ultraviolet A protection and the labelled factor, which is a defined threshold and more informative than the phrase.

Does the phrase appear alongside a claim about what the protection allows, such as protection from ageing or from all ultraviolet damage? Claims of that kind take the wording beyond a description of spectral coverage into territory where the evidence requirement is considerably higher, and where a claim can cross into implying a medicinal purpose.

Is the phrase being used comparatively, for example as broader than or the broadest? Comparative claims require substantiation against the comparison being made, and a comparative on a term with no fixed definition in this jurisdiction is difficult to support.

The claim that usually travels with it

Broad spectrum rarely appears alone. It is commonly paired with wording about premature ageing, on the reasoning that longer wavelength ultraviolet is associated with photoageing while the shorter wavelengths are associated with reddening. The pairing is not unreasonable in principle, and it changes the evidence requirement considerably.

A statement that a product protects across both ultraviolet ranges is a statement about the product's optical performance, and it is supported by absorbance testing. A statement that a product prevents, reduces or protects against premature skin ageing is a statement about an effect on skin over time, and the evidence required to support it is of an entirely different kind. Under the common criteria for cosmetic claims, a claim must be supported by adequate and verifiable evidence, and the evidence has to match the claim actually made rather than a narrower one nearby.

There is a further boundary beyond that. Wording that presents a product as preventing or treating a disease can take it outside the cosmetics regime altogether and into the definition of a medicinal product, which is assessed on presentation as well as on function. Where a sun protection claim starts to sound like a health outcome rather than a product property, the question of classification arises, and the MHRA guidance on what is a medicinal product becomes the relevant reading.

The translation problem

A practical complication for anyone working across markets is that the phrase does not translate cleanly, either between languages or between regimes. Wording drafted to satisfy a jurisdiction where the term is defined carries accompanying statements required by that jurisdiction's labelling rules, and those statements make no sense on a British pack. Wording drafted for the British market and then exported carries a term that will be read against a definition it was never tested to.

The pattern that causes enforcement problems is the one that treats the strongest available phrasing as a default and then applies it everywhere. It produces packs that overstate in one market and understate in another, and it makes a product information file harder to defend, because the evidence held has to support every claim actually made in every market where it is made.

If you are drafting the wording

The safer construction states the fact rather than the label. Wording that describes protection against both ultraviolet A and ultraviolet B, supported by the testing held, says the same thing without borrowing the authority of a defined term from a jurisdiction whose rules do not apply.

Where a product is sold into multiple markets, the position is more awkward, because the same words carry different regulatory weight in each. That is an argument for market specific artwork rather than for using the strongest available phrase everywhere, which is the pattern that produces enforcement problems.

What to take from this

Broad spectrum describes coverage across the ultraviolet band. It has a test and a threshold behind it in the United States. In the United Kingdom it rests on the general requirement that claims be truthful and supported, with the circled ultraviolet A mark carrying the defined threshold instead.