Weather forecasts now include a warning about ultraviolet levels and everyone knows they should apply sunscreen. However, this type of protection is a recent innovation.
Sunscreen was first used on a large scale during the second world war, when the US military experimented with substances to prevent sunburn. “Red Vet Pet” – short for red veterinary petrolatum – was included in life-raft survival kits for downed airmen. This is a form of petroleum jelly, previously used to treat cuts and burns. It was found to block ultraviolet light, but was oily and unpleasant to apply.
After the war, Benjamin Green, a pharmacist formerly of the US air force, mixed Red Vet Pet with coconut oil and cocoa butter to create a more pleasing texture. His market was leisure rather than survival, helping people to acquire a fashionable tan without getting burnt. Green sold his creation under the name Coppertone, and it became one of the first commercially successful sunscreens.
Since then, decades of research have produced increasingly effective protection. Sunscreen still contains organic substances to absorb UV, but may also include something to reflect it, such as fine particles of zinc oxide. Red Vet Pet had a sun protection factor (SPF) of two, meaning it doubled the time you could remain safely in the sun; modern sunscreens go up to SPF 100.