Today we wanted to talk about PLA.
PLA, or poly lactic acid, is a so-called biodegradable bioplastic.
Traditional plastic is made from petroleum-based raw materials. Some say bioplastics—made from 20 percent or more of renewable materials—could be the solution to plastic pollution. The often-cited advantages of bioplastic are reduced use of fossil fuel resources, a smaller carbon footprint, and faster decomposition. Bioplastic is also less toxic and does not contain bisphenol A (BPA), a hormone disrupter that is often found in traditional plastics.
However, it turns out that bioplastics are not yet the silver bullet to our plastic problem.
Degradable, biodegradable and compostable… What do those terms mean anyway?
- Degradable – All plastic is degradable, even traditional plastic, but just because it can be broken down into tiny fragments or powder does not mean that the materials will ever return to nature. Some additives to traditional plastics make them degrade more quickly. Photodegradable plastic breaks down more readily in sunlight; oxo-degradable plastic disintegrates more quickly when exposed to heat and light.
- Biodegradable – Biodegradable plastic can be broken down completely into water, carbon dioxide, and compost by microorganisms under the right conditions. “Biodegradable” implies that the decomposition happens in weeks to months. Bioplastics that don’t biodegrade that quickly are called “durable,” and some bioplastics made from biomass that cannot easily be broken down by microorganisms are considered non-biodegradable.
- Compostable – Compostable plastic will biodegrade in industrial composting facilities. Microorganisms break it down into carbon dioxide, water, inorganic compounds and biomass at the same rate as other organic materials in the compost pile, leaving no toxic residue.
Bioplastics are currently used in disposable items like packaging, containers, straws, bags and bottles, and in non-disposable carpet, plastic piping, phone casings, 3-D printing, car insulation and medical implants.
One of those bioplastics, PLA or poly lactic acid, is derived from starchy sources – most often sugarcane or corn starch – and was promoted as a natural, bio based alternative to petroleum-based plastic.
Although it’s true that at some point it will biodegrade, the reality is that this process will take several hundred years in a typical landfill. To biodegrade, PLA requires a laundry list of conditions to effectively break down. Specifically, it needs oxygen, a temperature of 140+ degrees, and a 2/3 cocktail of organic substrate.
Collectively, these are absent in any scenario outside of industrial composting facilities – and who is sorting our trash and where are those industrial composting facilities here in Vietnam??
When buried in a landfill, a plastic bag made from corn may remain intact just as long as a plastic bag made from oil or natural gas. Also, rather then biodegrading, it can degrade, or break down into smaller pieces which will find their way into our oceans, marine animals, and eventually might end up on your plate.
Want to know more and get answers to your questions about plastic? Make sure you come and attend our talks about plastic at the 2019 Holistic Fair, our panel will be first class!