Adenosine triphosphate (ATP) assays have been used to quantify bioburdens (biomass) in low-organic-compound-content fluids (freshwater, seawater, cooling tower water, and similar fluids) since the early 1950s. The original methodology was labor intensive and required considerable laboratory skill. Over the past half-century, the protocol has been simplified substantially, but until recently, chemical interferences made it impractical to use the ATP test in metalworking fluids (MWF). This article presents precision and bias statistics for a new test protocol for ATP in emulsifiable oil, semisynthetic and synthetic MWF at end-use dilutions. Additionally it presents the results of field tests in which ATP data are compared with other MWF condition monitoring data. The field evaluation demonstrates the applicability of the new protocol to MWF bioburden condition monitoring.

During the past decade we have witnessed a tumultuous debate over the disease risks posed by microbes that inhabit metalworking fluid (MWF) systems. Not infrequently, that debate has occurred in the absence of satisfactory data. This paper addresses the author's perspective on what types of data are needed in order to assess the actual disease risks posed by MWF microbes. The approach must be multidisciplinary and coordinated, including stakeholders with expertise in epidemiology, fluid management, immunology, industrial hygiene, microbiology, and public health medicine. Traditional microbiological sampling and test methods must be augmented by new, consensus methods that are adopted by industry stakeholders. Entities performing these tests should be participating in interlaboratory cross-check programs. The author will use Mycobacterium immunogenum to illustrate the general model for this strategy.