The use of process water is commonly used as an environmental key performance
indicator (KPI) in the industry. It is influenced by the use of water-miscible process
fluids and is thus relevant to the environmental performance of the fluid management.
In comparisons between plants, the definition of the water used in the process is
important, since lowering chemical concentrations and consumption may not show in
the figure for process water use. In most cases however, decreased use of process
water correlates with a good maintenance and long life of chemicals (IAMS 1995).
Emission of VOC (correlating to solvent use) is another important environmental
indicator also related to the work environment and linked to chemical concentration
and equipment design. Usually the reported figure on VOC is calculated
from the use of chemicals containing volatile solvents. Hazardous waste generation
should be directly affected by the use of hazardous material and would be lowered
through substitution of less hazardous material.
The aforementioned measures are subject to limitations in production permits
etc. and thus considered relevant as indicators of environmental result. Other indicators
are the use of chemical concentrates in different categories, some of which
will be discussed in Section 11.4.2. In addition to environmental and health concerns,
many chemical fluids, especially cleaners and MWFs, severely affect the quality
and efficiency of metalworking production (Mont et al. 2006; Simpson et al. 2003).
Since process fluids are hazardous substances their use is heavily legislated which
increases their control costs and makes the reduction of their usage a financially
beneficial measure. These serve as drivers to continual reduction of the volume of
process fluids by introducing better filtering and promoting fluid recycling