Sustainability is no stranger to the packaging industry, but are you confused about some of the definitions of sustainability in packaging? Honestly, you may not be alone. One of the most confusing areas of sustainability: the intersection of ‘Compostable’, ‘Biodegradable’ and ‘Bioplastic’ packaging. Although these three terms are always mentioned together in discussions on the circular economy, they are not synonymous.
For example, many people may not know that plant-based packaging materials are not necessarily compostable or biodegradable by themselves; some compostable materials come from oil-based sources; in addition, compostable materials , it is also not necessarily biodegradable.
Bioplastics
“Bioplastics” are made from natural materials, most commonly sugars such as starch, cellulose, and lactic acid, such as soybeans, corn, algae, feathers, and wood. Corn starch is the most common material used to make bioplastics, polylactic acid (PLA); another popular bioplastic is polyhydroxyalkanoate (PHA) made from potatoes and rapeseed ). In addition, natural materials can also be fermented to form bio-based versions of traditional oil-based plastics, such as bio-PET (polyester resin).
Compostable
“Compostable” materials refer to fertilizers that naturally break down over time into nutritious, agriculturally useful fertilizers made using fungi, bacteria, animal protein and other organisms. There are currently two types of compostable materials – “Home Compostable” and “Industrial Compostable”. “Household composting” materials are those that can degrade at ambient temperatures along with food scraps, grass clippings, leaves or other organic materials. The certification standards for household composting materials are strict, and must degrade (physical decomposition) within 6 months and form compost (chemical decomposition) within 12 months to be certified as household compost. “Industrial composting” materials require higher temperatures and certain standard levels of carbon, oxygen, and nitrogen to degrade, but they break down faster. Additionally, industrial composting materials are certified to biodegrade and form compost within 180 days.
Biodegradable
“Biodegradable” materials refer to the use of biodegradation technology, so that materials can be metabolized and decomposed into natural substances (water, methane) by microorganisms in soil or water without external intervention. Buried biodegradable materials that can be certified must be anaerobic, or anaerobic. To meet the criteria for marine biodegradation, the material must physically decompose within 3 months and biodegrade within 6 months in water.
There are also several key differences between compostable and biodegradable materials – compostable materials cannot be degraded anaerobic like landfill biodegradable materials, nor can they degrade in water like marine biodegradable materials; Likewise, biodegradable materials cannot be composted due to their different decomposing environments.