How Clean is “Clean?”

This over-worn catchphrase has been the title or has at least appeared in countless articles on the subject of cleaning.  Is it in need of a well-earned retirement?  Probably, but in its defense, let me say that “clean” is a pretty nebulous thing.

A few minutes ago, I pulled up one of the leading dictionary websites to look up the definition of “clean” so that I might address this issue once and for all.  BIG MISTAKE!  I scrolled until my mouse was in the next cubicle and still hadn’t reached the end of the list of definitions. There are “clean” nuclear bombs, burglary suspects who are “clean” (and not necessarily in the sense of having bathed), and “clean” getaways, not to mention good, “clean” fun.  Even if one limits consideration to those definitions that apply to the realm of things we normally discuss here, the list is still quite impressive and far from concise.  So is the problem with the word or the concept of cleaning?

The word is innocent!  Clean is a broad concept and is many things to many people.  I will never forget the production manager who told me he needed “squeaky clean” parts and was able to demonstrate his goal by rubbing his finger on a part and making it “squeak.”  To make things even more complex, the concept continues to evolve within its many spheres as time passes.  Forty years ago, a vapor degreaser was considered the ultimate cleaning machine.  Anyone using a vapor degreaser to clean parts was on the “cutting edge” of cleaning technology.  By today’s standards, a vapor degreaser of the design used 40 years ago would be considered quite rudimentary and inadequate in many cleaning applications.  However, the vapor degreaser of 40 years ago was able to quickly and simply produce parts that met a certain set of desirable criteria that defined a clean part at that time.

Fast Forward to Today – – Restrictions on the use and outright elimination of many solvents have all but removed vapor degreasers from the industrial cleaning scene (although they are re-appearing as I review this post in 2020).  Parts formerly cleaned with vapor degreasers are now cleaned with a multi-stage wash, rinse, dry process using, primarily, water-based chemistries.  (The use of water, by the way, would have been out of the question 40 years ago because of rusting issues. – – Has iron changed?)  Are the parts cleaned in water today “clean?”  Of course they are!  In fact, they may be cleaner than they ever were during the hay day of the vapor degreaser.

Clean is a concept, not an absolute.  The definition of clean has many dimensions, one of which is the dimension of time.  What is clean to one person may be not be clean to another person.  And what is clean today for either person may not be clean for one and/or the other a year from now.  The target criteria for cleanliness keep moving as do the means of achieving them.  One finds frustration in the fact that the target also seems to move in direct proportion to the degree of scrutiny that is applied to it.  But that’s another topic for another day.