Scientists from RIKEN and the University of Tokyo developed a new type of plastic that fully dissolves in seawater, leaving no microplastics or toxins.

It is made from sodium hexametaphosphate, a common food additive, and guanidinium ions.

The material has the strength of regular plastic but breaks down into natural components when exposed to saltwater.

Those components can be reused by marine microbes and plants as nutrients.

It is non-toxic, flame-resistant, and does not release carbon dioxide during decomposition