This month, we’ll discuss the commonly held idea that aqueous cleaning is significantly more friendly to humans and to the environment than is solvent cleaning. There’s a great deal of partisanship around that idea.

I have worked professionally with state and locally-supported technology transfer organizations as well as regulatory agencies who won’t entertain consideration of any cleaning system that can’t be filled from a drinking fountain. For them, the word “solvent” is virtually synonymous with “toxic.”

I have also worked professionally with solvent manufacturers, manufacturers of solvent based cleaning equipment, and trade associations who promote the opposite opinion. Often their livelihood depends upon their success in that effort.

The fact is, however, that protection from solvents or aqueous chemicals, if hazardous, can be easily obtained through well-engineered, proven equipment. And both solvent and aqueous cleaning technologies have strengths and weaknesses and should be used as required by the circumstances of the cleaning problem.

Let’s examine three aspects of these two cleaning technologies: environmental effects, containment, and the advantages and disadvantages of their use.