Bristol inventors are behind plans to collect urine from thousands of women running the London Marathon and turn it into crop-growing fertiliser.

Start-up entrepreneurs Amber Probyn and Hazel McShane developed Peequal - a women's urinal - while studying at Bristol University. The pair say their invention is nearly three times faster than using a portable toilet and has previously been used at the sporting event to reduce queues.

This year the duo are working with fellow Bristol-based start-up NPK Recovery to recycle the urine collected. Urine from nine Peequal urinals, positioned at the marathon’s yellow start line, will be processed into fertiliser for wheat.

The 1,000 litres of urine will be used for field tests to improve the fertiliser and evaluate its performance on wheat. If used purely for growing, 1,000 litres of urine could grow wheat for approximately 195 loaves of bread.

Ms Probyn said: “We love coming to the TCS London Marathon because we firmly believe that women shouldn’t have to choose between starting their race on-time or waiting to go to the loo.

"We’re really proud that 1,000 litres of wee won’t go to sewage, and will instead be recycled into something amazing.”

Susan Farrell, who is running the London Marathon for the NSPCC, said it was "brilliant" the "wees of thousands of women" would be helping a good cause.

“I used Peequal’s novel urinals at Glastonbury - their design means they don’t sacrifice privacy and it honestly felt like we were cheating by skipping the queues. I used to watch guys breeze through and think, ‘Why can’t we have that?’ Now we do, and I really hope we get to see them at more events.”

Marathon runner and Peequal fan Susan Farrell
Marathon runner and Peequal fan Susan Farrell

NPK Recovery use bacteria to recover naturally occurring nutrients from the urine, creating a liquid fertiliser.

Hannah Vandenbergh, founder of NPK Recovery, said: “Urine doesn’t have to be a waste product and we’re excited to be playing a small part in helping support the sustainability commitments of the iconic TCS London Marathon.

"Ultimately, we want to help event organisers all over recycle their urine and reduce their carbon footprints.”

Kate Chapman, head of sustainability at London Marathon Events, added: “Part of our environmental strategy is to try and find an "onward use" for all waste that is generated at our events, for instance composting, reusing, upcycling and much more besides.

“We are delighted that the urine from the Peequal urinals can be used for something so positive rather than going to waste.”

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