At One Place

What is a Sunscreen made of?

What is a Sunscreen made of?
UV filters — mineral, chemical or both — suspended in an emulsion whose job is to hold them in an even film.

Sunscreen is regulated as an over-the-counter drug in the US and as a cosmetic in the EU, Japan and Australia, and that single administrative difference is why European and Asian sunscreens have access to modern broad-spectrum filters that have been waiting for US approval for two decades. SPF measures protection against UVB and sunburn only; UVA protection is shown separately by a PA rating or a circled UVA mark. Real-world protection is usually far below the labelled figure because almost nobody applies the 2 mg/cm² used in testing — about a teaspoon for the face and neck — so reapplying every two hours matters more than chasing a higher SPF number.

Component by component

Every material is a choice, and the third column is the constraint that drove it.
Part Material Why that material
mineral filters zinc oxide and titanium dioxide They absorb and scatter across the UV range, are photostable, and are the only filters generally recognised as safe and effective by the US FDA.
organic filters avobenzone, octocrylene, homosalate, octisalate, and outside the US, Tinosorb and Uvinul filters They absorb specific UV wavelengths and feel far lighter on the skin than mineral filters at the same protection level.
stabiliser octocrylene or a dedicated photostabiliser paired with avobenzone Avobenzone is the main UVA filter available in the US and degrades in sunlight within an hour unless it is stabilised.
emulsion base water, oils, emulsifiers and thickeners Protection depends on an even, thick film; the base decides whether it spreads evenly and stays put in sweat and water.
film formers polymers that resist water and rub-off Water resistance is tested for 40 or 80 minutes; nothing is waterproof, and the label is not allowed to say so.

Other around the house objects

Common questions

What is a Sunscreen made of?
UV filters — mineral, chemical or both — suspended in an emulsion whose job is to hold them in an even film.
What is the mineral filters of a Sunscreen made of?
Zinc oxide and titanium dioxide. They absorb and scatter across the UV range, are photostable, and are the only filters generally recognised as safe and effective by the US FDA.
What is the organic filters of a Sunscreen made of?
Avobenzone, octocrylene, homosalate, octisalate, and outside the US, Tinosorb and Uvinul filters. They absorb specific UV wavelengths and feel far lighter on the skin than mineral filters at the same protection level.

Related pages

Sources

  1. Official vendor product documentation — At One Place

How these figures are compiled and checked