PROBLEM TO BE SOLVED: To provide a biofilm formation inhibitor that does not damage piping or devices and is also safe for human bodies.SOLUTION: A biofilm formation inhibiting method includes adding hexyl resorcinol to target water with a concentration of 200 ppm or less.SELECTED DRAWING: NoneCOPYRIGHT: (C)2018,JPO&INPIT【課題】配管や機器に損傷を与えることがなく、かつ人体にも安全なバイオフィルム形成抑制剤の提供。【解決手段】ヘキシルレゾルシノールを対象水中に200ppm以下の濃度で添加することを含む、バイオフィルム形成抑制方法。【選択図】なし