Methylisothiazolinone yang dikenal dengan MI dipakai untuk mengawetkan produk kosmetik dan rumah tangga, seperti tisu basah, shower gel, deodoran, dan pembersih wajah.
They are used to control bacteria, fungi, and algae in cooling water systems, fuel storage tanks, pulp and paper mill water systems, oil extraction systems, wood preservation, and some paints. They are antifouling agents. They are frequently used in shampoos and other hair care products.