Eco Simple Hair Bobby Pin Set Set of 2 Material: 100% Biodegradable Cellulose Acetate Acetate is plant-based biodegradable plastic in the simplest form. Cellulose acetate is made out of processed wood pulp, and also often regarded as nontoxic, nonirritant, and biodegradable material. Acetate is far more flexible and durable compared to conventional plastic that are fossil fuel based.