1.1This practice describes a direct microscopic counting method (DMC) for the enumeration of the acid fast stained mycobacteria population in metalworking fluids. It can be used to detect levels of total mycobacteria population, including culturable as well as non-culturable (possibly dead or moribund ) bacterial cells. This practice is recommended for all water-based metalworking fluids.

1.2This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. For additional safety information, see Laboratory Safety: Principle and Practices, 4th Edition²