The Problem with Bioplastics 

Bioplastics are quite the hot topic these days. From plastic cups with a green stripe around the base to utensils that proclaim they are 100% compostable, is it all too good to be true? The plastics industry is notorious for employing tactics such as misleading labels and mastering the art of greenwashing in order to make their product more appealing to eco-conscious customers. But what are bioplastics exactly and why are they such a source of controversy?  

Bioplastics can serve as a catch-all term for a few different types of materials. Bioplastics are often made at least in part of some form of organic material; however, they only need to be composed of 20% bio-based material to qualify as a bioplastic. Biodegradable plastics are plastics that can be broken down in nature, in water, or by various organisms. Sometimes even petroleum-based plastics can qualify as ‘degradable’ if certain organisms such as bacteria can break them down. Compostable plastics are plastics made of 100% organic material that are, in theory, supposed to break down in an industrial compost facility along with the food scraps and yard trimmings to form finished compost to be used on crops or gardens.  

Unfortunately, this does not mean any of these materials will break down in a landfill or in an industrial composting facility. Landfills lack the required exposure to air and sun for organic material to break down. Organic material in the landfill, including bio-based plastics, releases methane – a harmful greenhouse gas that contributes to climate change. So-called ‘compostable’ plastics often don’t break down in industrial composting facilities because they either don’t meet the required heat threshold or time period for them to break down into finished compost. Therefore, as a general rule in the RethinkWaste service area, we only accept BPI-certified compostable bags in the green compost bin. Hard compostable plastics need to be landfilled because they don’t break down during the 60-120 day period at the industrial composting facilities we send our material to. Additionally, many countries around the world, particularly developing nations where plastic pollution is an even greater problem, don’t have the infrastructure for industrial composting facilities. This means that compostable plastics are not yet a global solution to the prevalence and pollution of plastic products.  

An additional consideration regarding the production of bioplastics is that the product must come from organic material. The most used bioplastics are polyhydroxyalkanoate (PHA) and polylactic acid (PLA). PHA is typically composed of sugars grown from algae or produced by microorganisms. PLA, the cheaper and more prevalent of the two, is composed of sugars from corn and sugarcane. Growing these crops for the purpose of making bioplastics requires more land for agriculture that could otherwise be used to grow food for Earth’s growing population.  

Another important consideration in the bioplastic debate is how to dispose of these single-use products on a large scale. Despite the impressive advancements in technology that allow manufacturers to create products out of organic material, the burden is still on the consumer to figure out how to dispose of the product. Thankfully, the implementation of extended producer responsibility laws for plastics are being put into place in California, which mandates manufacturers to take responsibility for the lifecycle of their products, from design to their end-of-life.

Though there are drawbacks to bioplastics, there are positives as well. First, organic material is renewable as opposed to the oil used to produce traditional plastics. Bioplastics also don’t contain BPA and won’t leach toxic chemicals into food or soil therefore causing disease or harming the environment like traditional plastics. From production to breaking down, bioplastics produce fewer greenhouse gas emissions than traditional plastics as well.  

In summary, bioplastics are not a magic solution to the world’s plastic problem. Bioplastic production can use up valuable natural resources that could otherwise be used to grow food, they often don’t break down in industrial composting facilities, and they place a burden on the consumer to determine how to dispose of them properly. While there are promising developments in the field, such as creating bioplastics from wastewater or food scraps, avoiding plastics altogether is the most conducive way to reduce your waste.  

Many cities in San Mateo County have passed a Disposable Food Service Ware Ordinance, which requires a transition to fiber-based foodware products in restaurants; a step in the right direction for ensuring that single-use foodware is actually compostable. Purchasing products wrapped in paper or fiber (which can be composted), using reusables, and refusing plastics whenever possible are the best way to reduce your plastic consumption, at least until bioplastics have fewer negative environmental impacts and can be reliably composted.