Investigation of Inter-Laboratory Variability in AATCC TM100-2012

AATCC TM100 is one of a number of standard test methods commonly used for quantitative assessment of antimicrobial textiles performance. However, as currently written, the method allows for a number of steps to be conducted with several options, with reproducibility between testing laboratories being problematic. Options for the number of swatches and inoculum carrier (nutritive vs non-nutritive) were hypothesized to be primary drivers for variability. The present study attempted to identify sources of inter-laboratory variability. It was shown that specifying the number of swatches and inoculum carrier did not eliminate variability, as these parameters were not alone responsible for the outcome. Many other parameters were assumed to not affect the outcome. Additional systematic examination of these parameters was needed to determine their role in causing inter-laboratory variability.