Abstract: A metal working process employs a metal working fluid which is water-based and which is one of neutral and basic, the metal working fluid including a corrosion inhibitor in an amount ranging from 0.1 to 10% by weight; a lubricant selected from the group consisting of mono- or dicarboxylic acids or esters thereof having more than 10 carbon atoms, organic phosphate esters containing one or two hydrocarbon groups having 6-18 carbon atoms, and nonionic alkylene oxide adducts having a molecular weight above 400, and mixtures thereof; and an antimicrobially active amount towards fungi and bacteria of at least one alkanolamine compound having the following general formula ##STR1## wherein R is an acyclic hydrocarbon group having 8-14 carbon atoms, A is an hydroxyalkyl group having 2-4 carbon atoms, and X is one of hydrogen. The at least one alkanolamine compound prevents microbial degradation of water-based fluids when included therein.