Daily Sunscreen Fluid SPF 50 PA++++

Details

The sunscreen for an ordinary day. Office, commute, school run, a walk at four in the afternoon. It spreads like a light lotion, dries matte in about a minute, and leaves no cast on any skin tone. Nineteen ingredients, all below with percentages. SPF inflation is the sharpest cheat in Indian personal care, because a sunscreen that under-delivers is a burn the customer cannot see coming, and market testing here has repeatedly found labelled SPF not being met. So the whole result is on the page. In vivo SPF to ISO 24444, on human volunteers, ten subjects: mean 54.1, which labels as SPF 50. UVA measured in vivo as persistent pigment darkening to ISO 24442: UVA-PF 18.6, which is PA++++. 18.6 divided by 54.1 is 0.34, above the one third of SPF a broad-spectrum sunscreen is supposed to hold. Critical wavelength 383 nm to ISO 24443. SPF alone says nothing about UVA, and UVA is the half that ages skin and passes through window glass. The filters are the second half. This is the one thing a sunscreen listing must not blur, so all four are named with their percentages and with the ceiling each one is allowed, so the headroom is visible rather than implied: diethylamino hydroxybenzoyl hexyl benzoate 4.0 of a permitted 10, methylene bis-benzotriazolyl tetramethylbutylphenol 4.0 of 10, bis-ethylhexyloxyphenol methoxyphenyl triazine 3.0 of 10, ethylhexyl triazone 3.0 of 5. Fourteen percent in total. A photostable-filter list is what lets a sunscreen be this light and still test above 50; the alternative is more filter, a heavier film, and the greasy sunscreen nobody wears twice. And the figure nobody prints: the rating assumes 2 mg of product per square centimetre of skin, and studies of real use find 0.5 to 1.0. Protection falls roughly as a power of the dose, so at half of it you get roughly the square root, and SPF 50 applied at 1 mg per sq cm behaves like about SPF 7. At 0.75 mg per sq cm, about SPF 4.3. Face and neck are about 600 sq cm, so a correct dose is 1.2 g, which is two full finger lengths. A 50 ml bottle is 41 correct applications, about six weeks at one a day. If a bottle of sunscreen lasts you six months, you are not getting SPF 50 from it. This and the mineral sunscreen are a real choice, not a good one and a worse one. Take this one for daily wear, for oily skin, for under make-up, and above all if a white cast would stop you wearing sunscreen at all, which matters most on deeper skin tones. Take the mineral one if your skin is reactive or post-procedure, if organic filters sting your eyes when you sweat, if it is for a child over three, or if you will be in water, because the mineral one carries a water resistance figure and this one deliberately does not.

• Full INCI, in descending order: Aqua, Dicaprylyl Carbonate, C12-15 Alkyl Benzoate, Glycerin, Diethylamino Hydroxybenzoyl Hexyl Benzoate, Methylene Bis-Benzotriazolyl Tetramethylbutylphenol, Bis-Ethylhexyloxyphenol Methoxyphenyl Triazine, Ethylhexyl Triazone, Niacinamide, Polyglyceryl-6 Distearate, Silica, Cetearyl Alcohol, Panthenol, Phenoxyethanol, Sodium Acrylates Copolymer, Tocopherol, Xanthan Gum, Ethylhexylglycerin, Citric Acid
• With percentages: Dicaprylyl Carbonate 5.0, C12-15 Alkyl Benzoate 5.0, Glycerin 5.0, Diethylamino Hydroxybenzoyl Hexyl Benzoate 4.0, Methylene Bis-Benzotriazolyl Tetramethylbutylphenol 4.0, Bis-Ethylhexyloxyphenol Methoxyphenyl Triazine 3.0, Ethylhexyl Triazone 3.0, Niacinamide 2.0, Polyglyceryl-6 Distearate 2.0, Silica 2.0, Cetearyl Alcohol 1.5, Panthenol 1.0, Phenoxyethanol 0.7, Sodium Acrylates Copolymer 0.5, Tocopherol 0.3, Xanthan Gum 0.3, Ethylhexylglycerin 0.1, Citric Acid to pH, and Aqua is the balance at 60.6
• The 1 percent line falls after the panthenol
• No white cast, and that is measured rather than described: colourimeter reading on volunteers across Fitzpatrick III to VI, delta E below 1.0 at 15 minutes, which is below what an eye can pick out
• Niacinamide 2.0 percent, which is a modest conditioning dose and we will say so. If you want niacinamide at a working strength, the light gel moisturiser on this shelf carries 4.0 percent
• Measured pH 6.0, set by the niacinamide, which hydrolyses to nicotinic acid below about pH 5, and nicotinic acid is what makes a face flush
• No oxybenzone, no octinoxate, no octocrylene, no 4-methylbenzylidene camphor
• No alcohol denat. The matte finish is silica at 2.0 percent and the acrylates polymer at 0.5, not evaporating alcohol, which is the cheap way to make a sunscreen feel light and the reason so many of them sting
• No fragrance, no parfum, no essential oil, none of the 26 EU declarable components
• No parabens, and no MIT or CMIT behind them. Phenoxyethanol 0.7 percent with ethylhexylglycerin 0.1 percent
• No mineral oil, no dyes, no tint
• Honest trade-off one: there is no water resistance claim on this bottle. It is a daily fluid for an office and a commute. In water or heavy sweat it comes off, and the mineral sunscreen with its 40-minute ISO 16217 figur