Furry Solutions

Polar bears thrive in the extreme temperatures of the Arctic region. But for years, scientists have wondered how their fur remains ice-free.

Now they know – it’s all about the grease, according to a new study.

Researcher Julian Carolan and his team tested ice adhesion on washed and unwashed polar bear fur, and compared the samples with human hair and synthetic ski equipment containing per- and poly-fluoroalkyl substances (PFAS), which are used because of their anti-icing properties.

Their results showed that polar bear fur with its inherent grease resisted the buildup of ice just as well as human-made PFAS coating, while washed fur lost its ice-repelling properties.

The secret lies in a special oily substance called sebum, which coats polar bear fur and repels ice, the researchers said.

“The sebum quickly jumped out as being the key component giving this anti-icing effect,” Carolan said in a statement.

Carolan’s team found that polar bear sebum contains a unique blend of cholesterol, diacylglycerols, and fatty acids – but without squalene, a compound found in human and sea otter hair.

“Its absence in polar bear hair is very important from an anti-icing perspective,” Carolan noted.

This special coating also gives them an edge when hunting seals: They can slide stealthily across the ice using the low-friction properties of their fur.

Still, the discovery also has real-world implications in addressing the issue of PFAS – commonly known as forever chemicals. The material is used in non-stick cookware, water-resistant fabrics, and industrial coatings, but has been linked to cancer, infertility, and other health risks.

Extracting large amounts of sebum from polar bears – an already vulnerable species facing habitat loss due to climate change – is not a viable option.

However, now that scientists have identified the unique composition of polar bear grease, they aim to develop PFAS-free coatings that mimic its properties.

“If we do it in the right way, we have a chance of making them environmentally friendly,” co-author Bodil Holst told the Washington Post. “That is certainly the inspiration here.”