A sustainable process or activity can continue for a long time. Thus, to live sustainably means leading an existence that does not deplete the resources supporting human life. While this often entails living more simply, the specialized language of sustainable thinking can be complicated.

Here we will explore the vocabulary of sustainability via cutlery. Intuitively, one recognizes metal forks, knives and spoons as fully sustainable because they can be reused endlessly. Even if metal utensils break or wear out, they can enter the closed-loop recycling process. This means that rather than going into the trash, the metal can be processed into reusable material (“recycled”) over and over without compromising its properties (“closed loop”).

Among disposable utensils, single-use plastic examples are entirely unsustainable. Raw materials are extracted and manufactured into goods that are packaged and transported—all this for items meant to do their job just once! However, pinpointing a more sustainable but still disposable alternative is no simple matter and calls for a life-cycle analysis. By examining such factors as raw materials extraction, energy consumption, emissions production, and waste, these quantitative assessments gauge the environmental impact of products from creation through disposal.

A lifecycle analysis published in 2022 by Cleaner Engineering and Technology, for example, compared conventional plastic utensils (plus cups and plates) with bioplastic alternatives. Though less sustainable than materials like bamboo and wood, bioplastic is primarily made from renewable (natural and replenishable) resources like corn, sugar beets, and potato starch. Microorganisms break bioplastic down over time, so it is biodegradable. Additionally, if subjected to high-heat industrial conditions, it is frequently compostable, meaning it degrades relatively quickly into organic matter during a managed process. Having considered the environmental impact of different types of tableware from cradle to grave in such categories as global warming, ozone depletion, acidification, and human toxicity (water contamination), the 2022 study concluded that overall, the compostable bioplastic tableware had a lower environmental impact than cutlery made of conventional plastic — but only if it was used more than 10 times.

And so simply choosing the most sustainable utensils is complicated. But when deciding between alternatives, it sure helps to recognize the vocabulary.

David Conwell is a former history teacher who belongs to Brunswick’s Sustainability Committee and the nationwide advocacy organization Citizens’ Climate Lobby.