Biodegradable Plastic – Withheld Promises

Supermarkets have been printing a lot of environmentally friendly statements on their plastic bags for the past years. You get to read stuff like ‘photodegradable’, ‘oxydegradable’ or simply ‘biodegradable’. Such plastics are prone to faster decay in the presence of light, oxygen, and moisture. Unlike bioplastics, biodegradable plastics are made of petrochemical (regular) plastics and do not always break down into innocuous substances as they sometimes leave behind a toxic residue, making them quite undesirable for composting.

Biodegradable plastics hold promise, but they are not quite the complete solution. Biodegradable plastics are good but the following are their limitations:

·  During decomposition in the landfills, some biodegradable plastics produce methane gas that adds to the global warming challenge. More so, they don’t always readily decompose and require high temperatures for decomposition to occur.

·  Commercial facilities test biodegradable plastics at 58 degrees Celsius and 60% relative humidity, whereas at-home composting mechanisms may not meet these conditions and may therefore produce incomplete biodegradation.

·    They are more expensive to produce and most use plant resources like molasses or corn, heightening competition for food supply and worsening food shortage (North & Rolf, 2014).

·      According to North & Rolf (2014), the need for durable plastics in some applications, and biodegradable compounds in others can be compensated by devising smart strategies; for example: ‘Plastics of low volume for medical applications may rely more on fossil fuel and be designed for durability, whereas high-volume uses for consumer products will have to be sourced from renewable material stocks and be programmed for rapid environmental decay (i.e. biodegradability). This strategy could prevent irreparable environmental damage from disposable plastic products, while maintaining and maximizing the benefits of plastics in specialized cases like medicine and public health.’

References

History of Plastics. (2015). Retrieved May 21, 2015, from SPI - The Plastics Industry Trade Association: www.plasticsindustry.org

Knight, L. (2014, May 17). A Brief History of plastics, natural and synthetic. Retrieved May 16, 2015, from British Broadcasting Corporation - BBC: http://www.bbc.com/news/magazine-27442625

Lytle, C. L. (2015). When The Mermaids Cry: The Great Plastic Tide. Retrieved April 15, 2015, from Plastic Pollution: http://plastic-pollution.org/

North, E., & Rolf, H. (2014). Plastics and Environmental Health: The Road Ahead. Reviews on Environmental Health, 28(1), 1-8. doi:10.1515/reveh-2012-0030

PlasticsEurope. (2015). What is plastic? Retrieved May 13, 2015, from PlasticsEurope: http://www.plasticseurope.org/what-is-plastic.aspx