Isothiazolones

Isothiazolones are a class of biocides used to control the growth of microorganisms in various industrial and consumer products. They are heterocyclic organic compounds containing a sulfur atom and a nitrogen atom within a five-membered ring. Common examples include methylisothiazolinone (MIT) and chloromethylisothiazolinone (CMIT), often used in combination.

These compounds function by disrupting critical cellular processes in bacteria, fungi, and algae, thereby preventing their proliferation. Their efficacy at low concentrations and broad-spectrum activity make them valuable in applications such as water treatment, paints, coatings, adhesives, cosmetics, and household cleaning products. They are added to extend the shelf life of these products and prevent spoilage.

However, isothiazolones can also be skin sensitizers, meaning repeated exposure can lead to allergic contact dermatitis in susceptible individuals. This has led to regulatory scrutiny and restrictions on their use, particularly in leave-on cosmetic products. While effective antimicrobial agents, their potential for causing sensitization necessitates careful formulation and labeling to ensure safe use. Research continues into the development of alternative biocides and strategies to minimize the risk of allergic reactions associated with isothiazolone use.