Comparatively Speaking: A Commentary on 'Cleaning'


The 'Comparatively Speaking' column on cleaning, sanitizing, disinfecting and sterilizing, written by Rick Theiner of Evonik and published on Dec. 22, 2020,1 was well-received and generated a good amount of interest. Karl Laden, of Alpa Cosmetics, offered one appropriate addition.

"'Cleaning' is more complicated than removing organic matter," he wrote, suggesting we should consider the definition of dirt to include "matter out of place" and cleaning as "removing matter out of place."2

I like that suggestion, as it eliminates the stigma that dirt is “bad.” It also links together processes; i.e., something necessary and desirable for the first step of a process can become “dirt” in a following process. Interesting perspective.

In her book, Purity and Danger: Analysis of Concepts of Pollution and Taboo (1966), anthropologist and former UCL professor Mary Douglas claims that dirt is simply "matter out of place." She highlights "dirt" as having the ability to "provoke cognitive discomfort and reactions of disgust." Our negative attitudes toward slime, insects and dirt in general amount to a mental classification of what we see, relying on culturally ingrained symbolism to draw the boundaries.

In the words of Mary Douglas, then, "Dirt is in the eye of the beholder." I agree; but if it is in the wrong place it needs to be removed.

Thanks for the comments!


3. Douglas, M. (966). Purity and Danger: An Analysis of Concepts of Pollution and Taboo. Available at:
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