Biodegradable plastics have certain social, environmental and economic benefits. However, they also have many practical and potential obstacles. After a desktop survey, we found that the following countries and international organizations hold a cautious attitude towards biodegradable plastics, which has certain reference significance.
1. Three international organizations pointed out the difficulties in the application of biodegradable plastics.
The United Nations (UN) mainly pointed out the difficulties in the application of biodegradable plastics for the back-end processing. Generally, "biodegradable" plastic items can only be completely decomposed when exposed to high temperatures above 50°C (122°F) for a long time. Incineration plants can meet the conditions, but it is difficult in the natural environment. Therefore, even bioplastics derived from renewable resources (corn starch, cassava root, sugar cane, etc.) or bacterially fermented sugars or lipids (PHA34) will not automatically degrade in the natural environment, especially in the ocean.
Similarly, the European Union (EU) also pointed out that most plastics currently labeled as biodegradable usually degrade under certain conditions. These conditions are not easy to find in the natural environment, so they still harm the ecosystem. Biodegradation in the marine environment is particularly challenging.
The difficulties pointed out by the Organization for Economic Cooperation and Development (OECD) involve many aspects. Bioplastics and other bio-based products have high social, environmental and economic benefits. However, despite the benefits, there are many actual and potential obstacles.
In terms of cost: the current production cost of bioplastics is higher than that of petrochemical products.
In terms of research: there is a lack of consensus on life cycle analysis methods, so it is difficult to fully evaluate the potential of bioplastics to reduce greenhouse gas emissions.
In terms of policy: in many countries, biofuel-related departments benefit from preferential policy systems, which are disadvantageous to the bioplastics-related departments that compete with them.
In terms of public attitudes: there is a possibility of public resistance to the use of synthetic biology and other technologies in advanced biological treatment facilities.
In terms of land resources: there are ongoing disputes over the relative advantages of using land for non-food purposes to produce crops;In addition, in countries with limited land resources, access to sufficient biomass sources is restricted and relies on international biomass trade. The lack of standardization and limited coordination of international standards on terms and concepts such as sustainability may become obstacles to international trade.
In terms of back-end processing: insufficient recycling and disposal infrastructure for biodegradable and persistent bioplastics has led to the accumulation of plastics and "microplastics" in the environment, especially in the marine environment.
In response to the difficulties in the application of biodegradable plastics, the European Union (EU) has proposed some solutions. First, provide consumers with clear and correct information to ensure that the existence of biodegradable plastics will not be used as a reason for littering. To do this, it is possible to clarify which plastics can be labeled as "degradable" and how they should be handled after use. Furthermore, the European Commission will identify applications with obvious environmental benefits to stimulate innovation and push the market to develop in the right direction. In order to fully classify and avoid false environmental declarations, the European Commission will propose uniform rules to define and label biodegradable plastics and biodegradable plastics, and will develop a life cycle assessment to determine the conditions under which it is beneficial to use, and clarify standards for such applications. Finally, some alternative materials that claim to have biodegradable properties, such as "oxidative degradable plastics", have not actually been proven to have environmental advantages, but will quickly decompose into microplastics. The European Commission has begun to work to restrict their use.
2. The United Kingdom, the United States and Canada are conservative in the application of biodegradable plastics.
The United Kingdom does not support the widespread use of industrial compost packaging at this stage, because the general waste management infrastructure for industrial degradable plastic packaging is not yet suitable for use. In addition, if there is no special compostable waste bin, consumers may be confused about how to dispose of compostable packaging, which may lead to pollution of the recycling of ordinary plastics (if biodegradable plastics are mixed in the recycling process of ordinary plastics, it may be leading to the deterioration of the quality or durability of recycled products) and the phenomenon of littering. Enclosed environments can be exceptions, such as sporting events and workplaces with catering facilities, where there are specialized processing and collection services.
British scholar Sarah Greenwood pointed out that compostable packaging is not as “compostable” as most people imagine. In fact, "it can't", it will become "carbon dioxide, water or methane", "leaving a small amount of biomass" is a very, very slow process.
In addition, there are some unconclusive questions: Will the widespread increase in biodegradable waste lead to more methane emissions? Food packaging and food safety issues? Is there a burden for the related additional testing costs? And in the current standard, the biodegradable plastic that eventually enters the sewer may block the sewage system.
In 1992, the US Federal Trade Commission (FTC) formulated the "Green Guidelines" for the use of environmental marketing statements to provide manufacturers and marketers with specific guidance on acceptable environmental benefits statements for their products. The guidelines apply to advertising and marketing practices for various material types, including biodegradable plastics. In 2011, the United States passed a legislation that expanded the scope of restricting the use of degradable terms to almost all plastic products. The law requires clear scientific evidence for environmental claims, pointing out that biodegradation is a complex process that depends on physical and chemical structures, environmental conditions, and time. In 2012, the "Green Guide" added examples and guidance on the use of terms such as "compostable" and "degradable".
In Canada, plastic bags have been banned in Toronto since 2013. The ban includes "degradable, biodegradable, photodegradable or similar materials."
3. California and Maryland conduct marketing supervision on biodegradable plastics
California, the United States, has passed strict laws regulating the marketing and labeling of degradable plastic products sold in California, including those that claim to be "degradable" or "biodegradable" plastic products. Environmental marketing must be proven by reliable scientific evidence and meet the prescribed standards to prevent misleading consumers about the impact of degradable plastic products on the environment.
In 2011, the California Attorney General filed an unprecedented "green cleaning" lawsuit against three companies, pointing out that their "100% biodegradable and recyclable" statement made false and misleading statements. According to a settlement agreement reached in 2012, these companies were required to remove expressions of biodegradability and recyclability from their additive-based products, pay settlement fines and fees, and notify customers.
Los Angeles, located in southwestern California, does not recommend the use of "bioplastic" or "compostable plastic" products because they cannot be composted locally. Contaminants from the Los Angeles Roadside Recycling Program and Commercial Franchise Recycling Program include "bioplastic" or "compostable plastic" products.
From October 1, 2018, the State of Maryland in the U.S. prohibits anyone from selling specific plastic products that are biodegradable, degradable or decomposable, with certain exceptions; And it is forbidden for anyone to sell designated plastic products marked as compostable or household compostable unless the plastic products meet the designated standards. In response to the injunction, establish designated penalties and stipulate the sanctions for specific penalties.
In addition, the government of Portland, a city in Oregon in the United States, pointed out that plastic items marked "degradable", "biodegradable" or "plant-made" cannot be composted in Portland. And its negative impact on the environment may be equal to or greater than traditional plastics, and it is unlikely to reduce plastic pollution in the ocean. With the improvement of "compostable" disposables technology, this situation may change.
4. The application of biodegradable plastics should be treated with caution
The actual and potential obstacles of biodegradable plastics are reflected in many aspects such as cost, research, policies, public attitudes, land resources, and back-end processing. In addition, those issues that have not yet been concluded cannot be ignored, including the increase or decrease of methane emissions, food packaging and food safety issues, and the possibility of biodegradable plastics blocking sewage systems.
The United Nations (UN), the Organization for Economic Cooperation and Development (OECD) and the European Union (EU) all pointed out the difficulties in the application of biodegradable plastics. In response to the difficulties, the European Union (EU) tried to propose solutions. The United Kingdom, the United States and Canada are conservative in the application of biodegradable plastics. California and Maryland in the United States carry out marketing supervision on biodegradable plastics. These cases have a certain reference value, and we can realize that: the application of biodegradable plastics is not a simple and feasible solution, and should be treated with caution.
