How does suncream protect you from sunburn? © iStock

How does suncream protect you from sunburn?

No one likes the red lobster look, and science knows how you stop it. Warning: this answer is absorbing.

Asked by: Alex Round, London
Opaque sunblocks are effectively paint: particles of white titanium dioxide or zinc oxide suspended in a heavy oil. The oxide particles form an opaque barrier that reflects visible light and ultraviolet. Clear suncreams use organic compounds, such as Phenylbenzimidazole sulfonic acid, that only absorb ultraviolet wavelengths and let visible light through.

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