Water cremation (resomation)

Water cremation, also called resomation or alkaline hydrolysis, uses heated water and an alkali in a sealed steel chamber in place of flame, and returns soft white ashes to the family. It uses about a quarter of the energy of a flame cremation. It is not yet offered in England and Wales, where the Law Commission is reviewing the law on new funerary methods.

How it works

The person is placed in a stainless steel pressure vessel with water and potassium hydroxide. At around 160°C under pressure the process takes 4 to 6 hours, and at a lower temperature, around 98°C, it takes 14 to 16 hours. What remains is soft white bone, which is dried, crushed to a powder and returned to the next of kin, much like the ashes from a flame cremation. It is also known as aquamation or biocremation.

Why families ask about it

Its supporters point to the energy it saves, about 90 kWh of electricity for each cremation, to fewer carbon emissions and pollutants, and to the absence of a chimney. Families who want a lower impact funeral often ask about it alongside a natural burial and a biodegradable coffin.

Why it is not available in England and Wales

There is no legal framework for it in England and Wales yet. One practical obstacle has been the liquid left at the end of the process: in 2017 Severn Trent Water refused a trade effluent permit for a council crematorium at Rowley Regis, and the water industry still has no standard for disposing of it. A Law Commission report recommends a legal framework, and proposes that using any new funerary method before it is regulated should be a criminal offence. It treats human composting the same way.

What families can choose today

A family in England or Wales who would have chosen water cremation can choose a flame cremation or a burial. A direct cremation avoids embalming and the transport and resources of a formal ceremony, and a natural burial uses a biodegradable coffin or shroud in ground kept as natural habitat.