Methylchloroisothiazolinone/methylisothiazolinone

Methylchloroisothiazolinone/methylisothiazolinone (CAS 55965-84-9), commonly identified as CMIT/MIT, is a broad-spectrum biocide active against bacteria, fungi, and algae across a wide range of industrial systems. Known commercially under trade names such as Kathon WT and Kathon 886, it is the active ingredient in Proclin preservative blends. Procurement teams source it primarily as a formulated aqueous concentrate.

In water treatment and cooling tower systems, CMIT/MIT controls microbial growth that would otherwise cause biofouling, corrosion, and process inefficiency. This ensures long-term operational stability. Oilfield and gas operations use it as an injection biocide to suppress sulfate-reducing bacteria in produced water and pipeline systems. This prevents the degradation of critical infrastructure.

Pulp and paper mills apply it to process water and slurries to prevent slime formation that disrupts production and contaminates finished product. It is essential for maintaining high output quality. In rinse-off personal care formulations and industrial coatings, it functions as an in-can and in-process preservative. This protects the integrity of the product against spoilage during storage.

CMIT/MIT is supplied as a stabilized aqueous solution, most commonly at 1.5% active concentration, though higher-concentration technical grades are available for industrial use. Standard supply formats include drums. IBC totes are also available for bulk industrial procurement. Grades vary by intended application, with formulations differentiated by the CMIT-to-MIT ratio and the presence of stabilizing salts.