Examples of certified compostable products can include:
- Cups, containers, and cutlery made from rigid compostable plastics.
- Plates, bowls, and containers made from compostable fiber-based materials (e.g., bagasse, wheat straw, other molded pulp).
- Cups for hot beverages made from paperboard with compostable coatings (e.g., hot cups).
- Flexible packaging, liners, and other films for food and non-food uses made from flexible compostable plastics (5).
Examples in which compostable materials are typically used today include tea bags, compostable bags for compost collection in cities, or packaging materials that often end up in organic waste streams (e.g., fruit/vegetable labels). Compostables may also serve a beneficial role for small-format applications (sachets and small wraps) in which recycling is not a viable solution due to food contamination or the small size of the package – if they can be kept out of the recycling stream. It can also be used effectively in food-service applications when it is likely to be contaminated with food and can be separated from the recycling stream. Applications for which compostable plastic packaging is used would ideally be consistent across the industry to avoid cross-contamination of compostable and recyclable material streams (3).
- Adherence to guidelines: Specific guidelines should be followed to ease the identification of compostable packaging by consumers, composters, and others while reducing contamination and improving composting programs. In North America, ASTM is an international standards organization developing such standards based on science-based methods and supported by the North American certifier, the Biodegradable Products Institute. It published guidelines to help labeling and identification of compostable products and packaging: ASTM D6400 for plastics or ASTM D6868 for end items incorporating plastic and polymers as coating or additives with paper or other substrates to be aerobically composted in municipal or industrial facilities (6). Brands should follow these or other relevant international compostability standards (e.g., ISO 18606 as international standards or EN13432 as the European standard). For home compostability, these standards are adapted by national certification programs (1, 2). The BPI certification scheme established requirements to be met by compostable packaging. To avoid unintended consequences, ensure that compostables create value at their end of life, and clearly communicate proper disposal routes to consumers and composters. Certification of compostable packaging is helpful (4).
- Design bio-based compostable plastics only with clear intent: Compostable materials should not be used as an acceptance of packaging being littered or leaking to the environment rather than being handled properly at their end of life. As outlined above, however, compostable packaging may be beneficial for specific formats and contexts, including packaging heavily contaminated with food or small packaging in which recycling is not a viable solution.
- Understand and design for available infrastructure: While composting infrastructure is evolving in the U.S., it is still in a nascent and highly regionalized state, especially when it comes to consumer materials and packaging. Composting facilities vary greatly regarding accepted materials; some accept only green waste (e.g., yard waste) while others accept food waste from commercial sources but not residential sources. As of January 2021, there are just over 102 known facilities (16% of all composting facilities) that accept compostable plastic packaging in the U.S. (2). GreenBlue developed interactive maps of composting facilities, as well as those accepting compostable packaging (7).
- Source sustainably: Compostable packaging material needs to be credibly certified as sustainably sourced or based on agricultural waste. Companies should use renewable materials from responsibly managed sources so that the composting process returns carbon to the atmosphere that was captured during the material’s production (1).
- Communicate and label clearly: To help consumers to properly dispose of compostables and composters to distinguish between compostable and conventional plastic, make clear which packaging is compostable and what should be done with it. Prominent labeling (e.g., the How2Compost label), striping, color-coding, standardized certification logos, and consumer education are important. Consumers tend to have a hard time understanding nuances of compostables and how “compostable” is different from “biodegradable” (1, 2, 3).
- Follow the “all-or-nothing” approach: Within closed systems (e.g., events/locations/food service), use only compostable or no compostable plastics in each application to avoid confusion with recycling. For open systems (e.g., residential collection), be mindful of possible contamination of the recycling system, of composting infrastructure, and labeling/consumer education issues as discussed (1).
- Consider rolling out in specific markets with dedicated composting infrastructure: Compostables can work as part of a dedicated (often closed) system within a specific region, which includes appropriate collection and processing infrastructure for compostable materials (including food and organics). For instance, BioPak established a hyper-local collection and composting service to ensure that compostable packaging, food scraps, and organic material are collected and composted in practice. Similarly, Vegware, a compostable packaging manufacturer, launched a partnership with Paper Round, a waste management company, to ensure compostable materials are collected and composted via a full-service offer (1).