Plastics are synthetic materials made from a range of organic polymers that are capable of being moulded when soft. Most plastics are currently made from fossil fuels, typically the by-products from the processing of oil or natural gas. However, there are now a range of bio-based polymers that are used to make plastics, including bioethylene, polylactic acid (PLA) and polyhydroxyalkanoate (PHA).
Generally, plastics are split into two broad families: thermoplastics and thermosets. Thermoplastics are a family of plastics that melt when heated and solidify when cooled, and can be repeatedly reheated, reshaped and re-cooled. They include polyethylene (PE) and polypropylene (PP), two polymers commonly used to make plastic bags. Thermosets are a family of plastics that undergo a chemical change when heated, forming an irreversible, crosslinked chemical bond. In contrast to thermoplastics, once cured, thermosets cannot be re-melted and reformed.
The history of plastics is generally dated to the 1860s, when Alexander Parkes invented Parkesine and John Wesley Hyatt invented celluloid, or to 1907-09, when Leo Baekeland made the first fully synthetic plastic, Bakelite. While used for various purposes from the late 1800s, it was not until the 1950s that the commercial production of plastics began in earnest. In 1950, global production was approximately 1.5 million tonnes (Mt). By 1964, it had reached 15 Mt. It hit 50 Mt in 1977, passed 100 Mt in 1989 and, in 2016, was 335 Mt.
The growth in global plastic production is a testament to the utility and economy of plastics. They are versatile, cheap, lightweight and, in many forms, durable. These characteristics have resulted in plastics becoming a central and inescapable part of modern life. Plastics now come in hundreds of different forms and are used to make thousands of different products, including phones, computers, motor vehicles, planes, cooking utensils, cutlery, stationary, food wrapping and bags.
While extremely useful, plastics can have adverse environmental impacts. These stem from how plastics are made through to how they are disposed. Amongst other things, plastics are a major source of litter, cause damage to marine animals and birds through ingestion and entanglement, and can absorb and redistribute other pollutants in the environment. Concerns about these and other related forms of pollution has led to calls for restrictions on the production and use of different types of plastics. One of the primary targets for reform has been plastic shopping bags.
Policy measures to reduce the use of plastic shopping bags have been introduced in approximately 90 countries at national, provincial and/or municipal levels. These measures typically target lightweight single-use plastic bags made of high or low density polyethylene (HDPE and LDPE bags). The Australian Capital Territory (ACT) introduced a ban on single-use plastic bags through the Plastic Shopping Bag Ban Act 2010 in November 2011, becoming the third Australian jurisdiction to do so.
Questions have been raised about the efficacy of the Plastic Shopping Bag Ban Act 2010 and whether additional measures might be necessary to ensure it achieves its environmental objectives. In response to these concerns, in December 2017, the Minister for Climate Change and Sustainability, Shane Rattenbury MLA, asked the ACT Commissioner for Sustainability and the Environment to evaluate the operation of the Plastic Shopping Bag Ban Act 2010 and assess whether any changes were warranted.
This technical report was commissioned by the ACT Commissioner for Sustainability and the Environment to address the issues raised by the Minister. The report is set out as follows. Section 2 describes the types of plastic bags within the scope of the review. Section 3 analyses the levels of plastic bag consumption and use in Australia and the ACT. Section 4 provides an overview of the environmental impacts associated with the production, consumption and disposal of plastic bags. Section 5 reviews the regulations concerning the sale and distribution of plastic bags in Australian jurisdictions. Section 6 reviews the literature on the environmental effectiveness of the plastic bag bans in Australian jurisdictions, and provides an analysis of the effectiveness of the ACT plastic bag ban. Section 7 analyses the challenges and costs associated with the ACT ban, focusing on retailer compliance costs, increases in household expenditure, government compliance and enforcement costs, and community support. Section 8 analyses options for reform of the plastic bag ban and section 9 concludes and provides recommendations.