Chemical Concentration – Economic and Process Considerations

I have talked before on the blog about the subject of chemical concentration and its relationship to cleaning.  A couple of recent incidents prompt me to re-address the subject of chemical concentration but from a little different angle.

It’s a “no-brainer” that cleaning chemicals are expensive and, with the possible exception of heat and labor, probably top the list of the ongoing costs of industrial cleaning.  It makes sense, then, to minimize the consumption of cleaning chemistry when possible.  We have all heard the stories about over-use of cleaning and other chemicals in the home.  For example, I have seen reports that indicate that, on average, we use at least 4 times more laundry soap and dish detergent than necessary to get our clothes and dishes clean, and at least twice the amount of shampoo and hair conditioner needed to keep our hair shiny and fresh-looking.  In fact, there is a growing belief that toothpaste isn’t required at all for dental health!!  This over-use of chemicals has been compounded by the fact that there is substantial evidence that householders have not reduced consumption to compensate for the new “extra strength” formulations. It should come as no surprise that the situation is not substantially different in the world of industrial cleaning with the prevailing belief that “more is better.”

Most technical data sheets for chemistry suggest appropriate ranges of temperature and chemical concentration for best results in typical applications.  Although well-intended, these recommendations can be misleading especially in cases involving a range of contaminants or if there is a change in the cleaning chemistry.  Many of the cleaning chemistries today are multi-purpose meaning that they can be used on a variety of substrates to remove a variety of contaminants.  The recommended use temperature and concentration provided in the technical data sheet, in most cases, brackets the entire range of uses often not supplying specific recommendations for any of them individually.  In most cases, concentrations on the lower end of the spectrum are adequate to get the job done.  An important step in reducing cleaning costs is to determine what concentration is required to get the parts clean and to put a procedure in place to assure that the requirement  for chemistry is met but not exceeded.  Instructions like “add two scoops of soap” or (and yes I’ve heard this) “add three glugs from the gallon jug” do not promote consistent and economic use of chemistry.  Also, the practice of adding chemistry to “refresh” the cleaning solution may or may not be appropriate depending on the cleaning mechanism of the chemistry being used.  If chemistry is being consumed in the cleaning process, yes, but if the addition is to compensate for the fact that the cleaning solution has become contaminated with soils removed by the cleaning process then the answer is no.  In this case, the cleaning solution should be discarded and replaced.  Otherwise it is akin to taking a bath in previously used bathwater – Yuck.

Despite the above, the final message here is not that everyone should use less cleaning chemistry but, rather, that cleaning chemistry should be used appropriately and in a consistent manner.  Experiment with reducing or increasing the concentration of chemistry in your cleaning bath.  If you can achieve the same result with less chemistry, why waste money!  In the next blog I’ll discuss some reasons other than $$ to know and understand your cleaning chemistry and use it appropriately.

–  FJF  –


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