This site is named after a word that is not allowed on the thing it describes. That is deliberate, because the gap between what people believe the word means and what sun protection actually does is the single largest source of preventable sunburn in outdoor life.
The argument is not complicated. Waterproof is an absolute claim. A waterproof jacket is a jacket that water does not get through. Applied to a film on skin, the word promises that immersion does not affect the protection, and that is not true of any sunscreen ever formulated. Films are lost to water, to sweat, to towels, to sand, to wetsuit seals and to hands. Some formulations resist that loss much better than others, which is a real and meaningful difference, but none of them are unaffected.
The framework that removes it
Two instruments matter in the UK.
The first is the European Commission Recommendation of 22 September 2006 on the efficacy of sunscreen products and the claims made relating thereto (2006/647/EC). It is a recommendation rather than a regulation, but it is the document that shaped the labelling conventions used across Europe and still used in the UK. It advises against claims that convey the idea of total protection, including terms in the family of sunblock and total protection, and against claims of protection lasting a whole day such as all day protection. It also sets the framework in which water resistance is expressed as a tested, relative property rather than an absolute one.
The second is Commission Regulation (EU) No 655/2013, laying down common criteria for the justification of claims used in relation to cosmetic products, retained in UK law. It requires that claims be truthful, supported by adequate and verifiable evidence, and not mislead by conveying characteristics the product does not have. It applies to sunscreen because sunscreen in the UK and EU is a cosmetic product under Regulation (EC) No 1223/2009, retained in UK law as the UK Cosmetics Regulation.
Put those together and the position is straightforward. A manufacturer must be able to substantiate a claim. Nobody can substantiate waterproof. So the word does not appear.
And then there is advertising
Product labelling is one system. Advertising is another, and in the UK it is policed by the Advertising Standards Authority against the CAP and BCAP codes. The codes require that objective claims be capable of substantiation and that marketing must not materially mislead. An absolute performance claim about a product that manifestly does not deliver absolute performance is exactly the sort of thing that framework exists to catch.
Product safety and compliance of cosmetics in the UK sits with the Office for Product Safety and Standards, working alongside local authority trading standards. Our note on who regulates sunscreen in the UK maps the whole picture.
What replaced it, and why the replacement is better
Waterproof
What it certifies
Nothing, in the UK or the EU. It is not a claim that a sunscreen may make here, because it conveys an absolute level of performance that cannot be supported by evidence. The permitted vocabulary is water resistant and very water resistant, both tied to a published immersion procedure.
What it does not
It does not indicate a stronger formulation, a longer wear time or a better product. Where it appears on a pack in a UK shop, the most likely explanations are that the product was made for a market outside the UK and EU regime, or that the labelling predates or ignores the guidance.
The permitted vocabulary is water resistant and very water resistant. Both are relative, both are tied to a published immersion procedure, and both are therefore checkable in principle. That is a genuine improvement on an absolute word, because a relative claim invites the right question: resistant compared to what, measured how, for how long? Our note on what water resistant actually certifies answers all three.
It also has a side effect that regulators may not have intended but which is useful. A person reading water resistant has to do a small amount of thinking. A person reading waterproof does not, and stops thinking entirely, which is precisely the failure mode that produces a burnt back after two hours of snorkelling.
Why you still see the word
Three reasons, in descending order of frequency.
Products made for other markets
The United States prohibited waterproof and sweatproof on sunscreen labelling in its 2011 labelling rule, so a modern US pack should not carry it either, but older stock, grey imports and products from markets with lighter enforcement all circulate. Our notes on the United States position and the Australian standard set out those regimes.
Loose language in marketing rather than on the pack
A pack may be compliant while a retailer's website description, a social post or a shelf barker is not. The advertising codes cover that material.
Ordinary speech
People say waterproof because it is the natural English word for the idea. Shops write it because customers search for it. That is why this publication exists at the address it does: the word is where the misunderstanding lives, so it is where the correction has to be published.
What this actually means when you are outside
- No claim on any pack means protection survives your session. The strongest permitted claim is tied to defined immersion periods, and those periods are short relative to a swim, a surf or a snorkel.
- Reapplication is not a hedge, it is the mechanism. Our note on reapplication as the dominant variable explains why it outranks the number on the front.
- Abrasion is not covered by anything. Not by water resistance, not by a factor, not by any word on any pack. Our note on water, sweat and rub resistance covers the gap.
- Textile does not have this problem. A rash vest is opaque and stays opaque. See UPF clothing.
The one place the word is fine
There is no objection to the word waterproof as applied to things that are actually waterproof. A drybag is waterproof. A jacket to a stated hydrostatic head is waterproof within a defined limit. A watch is rated to a depth. In every one of those cases the word describes a barrier that either admits water or does not, and the claim is testable in a way that maps onto what the word means in ordinary English.
A film on skin is not a barrier of that kind. It is a consumable layer that is worn away by everything it touches, and there is no rating at which the ordinary meaning of the word becomes true of it. That is the whole distinction, and it is why the same word is unproblematic on one shelf of a shop and impermissible on another.
What is not verifiable
We cannot tell you how any particular product behaves in water, because we test nothing and we name nothing. We can tell you what the regulatory framework permits and why, and we can tell you which claims have a published procedure behind them and which are marketing language. That is the useful half of the picture and it is the half that is public.
The point of the whole thing
The removal of waterproof from sunscreen labelling is one of the better pieces of consumer protection in the cosmetics field, because it does not just remove a false statement, it forces a true one into its place. Water resistant is an awkward, qualified, slightly disappointing phrase, and it is disappointing for an accurate reason. The film comes off. Plan for it.