• Giovanni Ocon

What Is the 'Waste Hierarchy?'

Waste is an essential portion of human life, produced every day in each of the world’s economic systems. It is defined by Encyclopedia Britannica as “the process of discarding by-products of metabolism.” However, waste is not only referred to in a biological context; it is also defined in terms of industrial capacity. For example, Wikipedia defines waste as “an unusable material.” This definition is more accurate in the highly industrialized 21st-century world. The concept of industrial waste does beg the question, how are we to effectively separate our waste? Furthermore, how are we to identify such waste to produce less?


Industrial waste management is most commonly separated through a hierarchy. A hierarchy is an arrangement of terms based on precedence. In other words, a hierarchy is how “high” or “low” an item is. In waste management, a hierarchy is the separation of waste based on its relation to sustainability. The levels of waste hierarchy are in chronological order; prevention, minimization, reuse, recycling, recovery, and disposal.



In an ideal situation, waste prevention is the most favorable option as materials are extrapolated for their optimal use without creating waste. Furthermore, following such a hierarchy reduces the amount of extraneous waste and eventual greenhouse gases. The next tier of the hierarchy is minimization. Minimization is an interesting tier as it does not reduce the precise amount of prevention, though it is responsible activity. Minimization is the deliberate reduction of an object which cannot be optimized. Though it is less beneficial than prevention, it remains a conscious effort to avoid waste. The next step is extremely beneficial for individual communities as it optimizes any object without initially creating waste, although the material is eventually wasted. The penultimate level is recycling, which is the most easily recognizable of these levels. Recycling is the process of converting former materials into new ones; Although recycling has historically been commended for universally reducing carbon emissions, certain evidence proves otherwise. For example Kitakyushu, Japan is considered an OECD Green city, internationally recognized for its environmental focus since the late 1960s. However, much of Kitakyushu’s private sector recycling efforts contribute to carbon emissions which would otherwise be avoided by lack of industrialization. In fact, a Nature.com study(1) references this phenomenon. However, recycling remains a viable option to avoid exploitation/waste accumulation. The final tier in the hierarchy is disposal. Disposal is the process of creating waste by disposing of a material. Disposal is the final tier of the hierarchy since it does not benefit and instead poses a detriment to the environment.


With the information about waste hierarchy, one asks themselves how they can positively impact waste management throughout their lives. The first step in evaluating waste management is to interpret the hierarchy to one’s habits and daily life. Furthermore, one must also evaluate their perspective on waste and assure not to seek disposal as a remedy to problems that could be resolved through prevention or minimization. A change of mindset is highly important in contributing to effective waste management. The next step is to create a strategy and integrate it into one’s life through a (preferably) centralized database. This database serves as the center of statistics, which serves as a metric for the strategy’s goals. After data collection for a few weeks, the final step is an analysis of the statistics in relation to the hierarchy. When analyzing data, identify the tier which it best reflects. If the statistics reflect a high amount of disposal, then perhaps it is time to evaluate one’s strategy as well. Overall, the main focus of waste management is to set clear goals (based on the hierarchy) with enough adaptability to strive for minimization. Have fun! After all, you’re helping the Earth!


  1. https://www.nature.com/articles/s41599-019-0369-8

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