The conditions files
Each file names a real activity or environment and sets out the ultraviolet load, the water and sweat exposure, the friction, the duration, what fails first and the protection strategy, with a reapplication clock showing what degrades over hours.
Open water swimming
Open water swimming is the condition the water resistance test was designed for and still does not describe. The immersion procedure behind a water…
Open file →
Surfing
A surf session is long, abrasive and reflective, and it happens in the hours when ultraviolet is strongest because that is when the tide and the wind…
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Sailing
Sailing combines the longest durations in watersport with a wind that removes the sensation of heat. Crews routinely spend an entire day on a…
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Road cycling
Cycling replaces water with sweat and replaces variety of posture with five hours in one position. Sweat carries sun protection off the forehead into…
Open file →Hill walking
A hill day is the longest continuous ultraviolet exposure most people take deliberately, and it takes place at an altitude where ultraviolet is…
Open file →
Ski touring
Snow at altitude is the most demanding ultraviolet environment in ordinary outdoor life. Ultraviolet rises with altitude and fresh snow is a strong…
Open file →The label decoder
A claim printed on packaging, what it legally certifies, and what it does not. It recurs throughout the site.
Waterproof
What it certifies
Nothing, in the UK or the EU. It is not a claim a sunscreen may make here, because it conveys an absolute level of performance that cannot be substantiated. 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. This publication is named after the word precisely because that is where the misunderstanding lives.
Standards notes
What a claim printed on packaging legally certifies, and what it does not. The UK and EU position, the United States, where sunscreen is regulated as a drug, and the Australian standard.
The waterproof claim
Waterproof, sunblock and all day protection are absolute claims that cannot be substantiated, which is why UK and EU sunscreen…
Open →Standards 02Water resistance testing
The immersion procedure behind a water resistant claim, period by period, and the six things about real water that it…
Open →Standards 03How SPF is tested
The in vivo sun protection factor method, what the number is a ratio of, and why the quantity applied in testing changes how you…
Open →Standards 04The UVA circle
What the UVA in a circle symbol certifies, how it relates to the SPF number, and why the star rating alongside it is a different…
Open →Standards 05The US position
Why American sunscreen is an over the counter drug rather than a cosmetic, what the Drug Facts panel tells you, and how US water…
Open →Standards 06The Australian standard
How Australia regulates sunscreen through the TGA and AS/NZS 2604, why the maximum labelled factor is 50+, and what an Australian…
Open →Field craft
The mechanics that decide whether protection works: how much goes on, how often it is replaced, what fabric does that a film cannot, what reflects off the ground, and the sites everybody misses.
Reapplication
Why frequency of reapplication outranks the factor, the formulation and the water resistance claim, and how to build a routine…
Open →Field craft 02How much to apply
The application quantity specified in the SPF test method is considerably more than people use in practice, which quietly lowers…
Open →Field craft 03Filters over eight hours
Photostability, heat, sweat and physical loss: the four things that change a sun protection film over a long day, and which of…
Open →Field craft 04UPF clothing
How the ultraviolet protection factor of fabric is rated, what changes when a garment is wet or stretched, and why textile beats…
Open →Field craft 05Reflected ultraviolet
Why shade is not shelter: how reflective surfaces deliver ultraviolet to skin that is shaded from the sky, and which body sites…
Open →Field craft 06UV index and altitude
What the UV index is, what its bands mean, why altitude and latitude change it, and how to use a forecast to make a decision…
Open →The four things that decide it
In order of effect. Sunscreen is last on the list, and that is not a criticism of sunscreen.
What this publication refuses to do
Set out here rather than buried, because it is the reason to trust anything else on the site.
- Name, rate, rank or recommend any sunscreen, brand or retailer. We have tested nothing.
- Publish an SPF measurement, a retention percentage or any laboratory figure of our own.
- Invent a statistic, a study or a rate. Where a number would go, we describe the mechanism and name the standard.
- Give diagnostic guidance about anyone's skin, or publish a self assessment checklist. That belongs with a GP.
- Run advertising networks, AdWords, sponsored articles or paid mentions.
The newsletter
A short note when a standard changes, a regulator publishes something relevant, or a new conditions file goes up. At most one clearly labelled sponsor line per issue, at published rates.
A short note when a standard changes, a regulator publishes something relevant, or a new conditions file goes up. No product recommendations, because we do not make any.