01ReapplicationWhy frequency of reapplication outranks the factor, the formulation and the water resistance claim, and how to build a routine that actually happens.Open →02How much to applyThe application quantity specified in the SPF test method is considerably more than people use in practice, which quietly lowers the protection everyone actually receives.Open →03Filters over eight hoursPhotostability, heat, sweat and physical loss: the four things that change a sun protection film over a long day, and which of them a label addresses.Open →04UPF clothingHow the ultraviolet protection factor of fabric is rated, what changes when a garment is wet or stretched, and why textile beats film wherever it is practical.Open →05Reflected ultravioletWhy shade is not shelter: how reflective surfaces deliver ultraviolet to skin that is shaded from the sky, and which body sites it reaches.Open →06UV index and altitudeWhat the UV index is, what its bands mean, why altitude and latitude change it, and how to use a forecast to make a decision rather than to feel reassured.Open →07Eyes and lipsUltraviolet and the eye, the standard sunglasses are tested to, why lips burn so readily, and what a sun protection routine misses by design.Open →08Scalp, ears and lipsThe parting, the crown, the tops of the ears, the backs of the hands and the tops of the feet: the sites that burn on people who consider themselves careful.Open →09Shade and timingWhy moving a day around the sun beats every product decision, how shade actually works, and what a realistic timing strategy looks like for outdoor people.Open →10Checking your skinHow to make skin checking a routine rather than an event, which sites outdoor exposure concentrates on, and why this page gives no diagnostic guidance.Open →
New files, when they land
We publish when a standard changes or when a condition is worth documenting properly, not on a schedule.
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.