Water cremation is set to be made available for the first time in the UK. The process, known as resomation, uses a mix of potassium hydroxide and water to break down human remains in what is billed as a more sustainable option. It takes four hours - the bones remain, and are powdered then returned to loved ones in a similar way to ashes, in an urn. Resomation is used in Canada, South Africa and many US states.