Conventional synthetic colorants don’t break down in the compost heap.
But a new family of all-natural colorants and additives are biodegradable and compostable. Renol-natur color and Cesa-natur additive masterbatches are based on natural and renewable materials such as flowers and can be compounded with sustainable biopolymers including PLA (polylactic acid), PHA (polyhydroxyalkanoate), PHB (polyhydroxybutyrate), and starchbased resins used in consumer packaging. Renol-natur colors include red, orange, yellow, and green, while blue is in the final stages of development. Orange curcuma comes from the root of the spice-plant turmeric, and yellow urucum is found in flowers that grow in tropical regions. The greens come from chlorophyll and other plant sources, while the natural carmine red colorants are derived from the cochineal insect. These colors can be combined to create additional shades and tones. Physical properties, such as lightfastness, are not as good as those of nonrenewable pigments, so the biodegradable colorants won’t work for all applications. All of the Renol-natur colors meet or exceed the EN 13432 standard for biodegradable plastics packaging, and European food-packaging approvals are expected in the near future.
Clariant Masterbatches, 85 Industrial Dr., Holden, MA 01520, (508) 829-6321, clariant.masterbatches.com