confusing terms …

degradable, biodegradable and compostable … they all mean different things … they’re often used interchangeably … however, when you’re dealing with man-made products (e.g., bioplastics) that have been stamped with a claim of being “environmentally friendly”, it is important to understand what means what … some company claims may be deceiving …

international standards for bioplastics are established largely by ISO, DIN, CEN, and ASTM International …

DEGRADABLE = the plastic will break down or fragment into smaller physical pieces and undergo significant change in its chemical composition under specific environmental conditions … degradation is not limited to occur via the biological activity of terrestrial or aquatic microorganisms, and there is no standard for regulating potential toxic residue resulting from the degradation of the plastic …

BIODEGRADABLE = the plastic will degrade via aerobic or anaerobic activity of naturally occurring microorganisms and/or fungi … there is no international standard for the time-frame within which biodegradation must be complete nor for regulating toxic residue … therefore, a biodegradable bioplastic may still contaminate ecosystems (e.g., toxic dyes, etc.) … total decomposition may be completed either under field conditions or under the high heat and humidity conditions in a commercial facility …

COMPOSTABLE = compostable plastics completely decompose in composts including vermicomposts, or under other aerobic or anaerobic conditions, via the metabolic activity of naturally occurring microorganisms and fungi … these bioplastics ultimately break down into CO2 gas, water, inorganic compounds (e.g., minerals), and hydrocarbon biomass (e.g., organic compounds) … no toxic residue remains and the biomaterial decomposes within the amount of time it would take for a similar, natural plant substance (e.g., cellulose) to decompose … the resulting compost must not contain any residual, undecomposed remnants of the original bioplastic and the compost must be able to support plant life (i.e., be non-toxic) …

few bioplastics are compostable, but these are the most environmentally friendly … sometimes, the difference between a biodegradable and compostable bioplastic is the use of toxic inks in the former material and the use of non-toxic, plant-based inks in the latter material …