Changes in concentration, emulsion hardness, and pH occur in the lifecycle of every metalworking fluid system.  Left alone long enough, these and related effects manifest themselves to produce sensory detectable problems.  How do you incorporate this into your boring Hazcomm training program?  This troubleshooting guide from Zebraskimmers provide a great photographic reference chart of these effects.  The pictorial representations are really easy to understand for your shop training purposes to raise the level of awareness of potential issues for all employees working around the fluids.  Well done Zebraskimmers!