ASTM E2694, the Standard Test Method for Measurement of Adenosine Triphosphate in Water-Miscible Metalworking Fluids has been approved for revision and is waiting publication. This method measures the concentration of ATP present in the sample. ATP is a constituent of all living cells, including bacteria and fungi. Consequently, the presence of ATP is an indicator of total microbial contamination in metalworking fluids.  This method differs from Method D4012 in that it eliminates interferences that have historically rendered ATP testing unusable with complex organic fluids such as MWF.