Staying safe in the sun is a perennial problem. Sun creams exist but they are not perfect. They only offer partial protection and they wear off easily. But could the answer lie in a load of old cod?

Researchers at the Escola Superior de Biotecnologia in Porto, Portugal have developed a sunscreen made from cod bones, a by-product of the food industry.

The material – a powder – is based on hydroxyapatite, a phosphate modified with iron and iron oxide, which absorbs UV radiation. It is produced by heating fish bones to 700 degrees Celsius and eliminating all organic material.

When the powder is incorporated into sun cream it gives good protection over the whole UV range, producing a broad spectrum sunscreen.

Manuela Pintado, a researcher at the Escola Superior de Biotecnologia, explained that testing is already underway: “We did human trials, in which we applied the cream and found there was no skin irritation. So it is safe to use.