An ingenious plan to turn hospital aprons and food waste into compost

Game Changers: The HaPPE compostable apron and biodigester system can be used to create relaxing gardens for patients and staff

As a doctor, Mary O’Riordan knows the guilt that medics feel about the plastic they discard every working day. Irish hospitals generate a staggering mountain of 50 million discarded plastic aprons every year, nearly a million a week. Single-use plastic is a double curse. The material itself is made from fossil fuels. When tonnes of lightly used disposable aprons are incinerated, they release twice as many tonnes of carbon into the atmosphere.

Working with her cousin Lisa O’Riordan, Dr O’Riordan set up HaPPE Earth, to make medical-grade compostable aprons. Compostable plastics aren’t a perfect solution to our single-use plastic addiction. They often aren’t composted, and are made from plants meaning they require land for production. So we can’t just drop them into our single-use habits and carry on. But there is a hierarchy of need. A hospital apron which protects people from infection is more urgent than a disposable coffee cup which saves us having to rinse out our keep cups.

The HaPPE Earth aprons are available now. The business is also planing a game-changing complimentary initiative, which could be part of a fix for another major problem in hospitals: food waste.

At a recent pitch jam event hosted by Furthr (a start-up support organisation based in the Guinness Enterprise Centre) Dr O’Riordan wowed the audience and won the competition. She explained how their aprons are better and potentially come with a better way to dispose of them. The answer comes in the shape of a biodigester. These are machines that use enzymes, heat, UV sterilisation and mechanical shredding arms to turn food waste (and compostable plastic) into compost on site in 24 hours.


Hospitals have a duty to provide everyone with a meal, Dr O’Riordan told us that evening – but many people don’t want to eat when they’re in hospital, so levels of food waste are huge.

A biodigester removes many of the problems that get in the way of on-site composting ,especially in a healthcare setting. These include smells, four-legged foragers and a long wait as your greens and browns turn into the good stuff. With a biodigester, the waste goes into one end of the machine, which can range in size from a large catering oven to a shipping container depending on the amounts of waste to be processed. A day later it is broken down into a useful crumbly fertiliser, putting the food and compostable waste back into the soil where it can help create healthy habitat.

The O’Riordans will be piloting the service next year in Ireland, the UK and the US as “an all in service, where HaPPE supply the compostable consumables, measure, report and through on site bio-digestion produce a nitrogen rich pathogen safe fertiliser,” Lisa explains. Waste could be used to create relaxing gardens, even pocket forests. Nature in situ for staff and patients can help ease the stress of hospital life.

Now that’s what I call a happy outcome.