PROBLEM TO BE SOLVED: To provide an antibacterial and antifungal process for water-soluble metal processing oil.SOLUTION: An antibacterial and antifungal process for water-soluble metal processing oil includes sustained injection, intermittent injection or intermittent addition of isothiocyanate into water-soluble metal processing oil.SELECTED DRAWING: Figure 1COPYRIGHT: (C)2020,JPO&INPIT【課題】水溶性金属加工油における抗菌防カビ方法の提供。【解決手段】イソチオシアン酸エステルを、水溶性金属加工油に持続注入若しくは断続注入若しくは断続添加することを特徴とする水溶性金属加工油の抗菌防カビ方法。【選択図】図1