Coatings, Paints & Inks

OIT 45%            

Metalworking Fluid Fungicide for Water-Based Cutting Fluids

Chemical Name: 2-n-octyl-4-isothiazolin-3-one(OIT)

CAS No: 26530-20-1


OIT-45 Biocide is a broad-spectrum fungicide that has been recommended and widely used for tankside control of fungi in metalworking central systems.

Typical Properties

These properties are typical but do not constitute specifications


Pale yellow to amber liquid

Active Ingredient

45% 2-n-octyl-4-isothiazolin-3-one

Flash Point, °C


Boiling Point, °C


Specific Gravity (g/ml) at 20°C


OIT-45 Biocide is soluble in methanol, ethanol, propylene glycol, acetone, ethyl ether, ethyl acetate, chloroform, butyl Cellosolve, corn oil, and mineral oil.
The solubility of OIT-45 in toluene is 25% w/v.
The solubility of OIT-45 in water at 25°C is 480 ppm (active ingredient), although this may be increased by using suitable surfactants and emulsifiers.
OIT-45 is insoluble in heptane.
In concentrate and use-dilution metalworking fluids, the compatibility of OIT-45 MW Biocide is concentration-dependent and varies from formulation to formulation. It is compatible with most metalworking fluid additives, including surfactants and amines.
Compatibility with amines may vary by the type, concentration and pH. Strong reducing agents, such as sulfides, mercaptans, bisulfites and metabisulfites, or strong oxidizing agents, such as hypochlorites, may affect the efficacy of OIT-45 Laboratory  or small-scale tests are recommended in order to evaluate OIT-45 compatibility in use-dilution or concentrate metalworking fluids prior to commercialization.
In-Use Stability: OIT-45 Biocide has excellent stability in end use dilutions of metalworking fluids. It is stable over a wide pH range (4-10) in water and in metalworking fluid systems. Concentrate Stability OIT-45 Biocide stability, in metalworking fluid concentrates, is variable. We recommend checking stability and performance beforecommercialization of products. Ozzie has several recommended stabilizers to improve stability and compatibility in many types of concentrates.
Storage Stability
In general, the storage stability of OIT-45 Biocide product is excellent. The shelf life of the product is nominally twelve years at 25°C. It is strongly recommended, however, that both the stability and compatibility of OIT-45 Biocide in metalworking fluid formulations or systems be thoroughly examined before commercialization.
Applications/ Directions for Use
Method of Addition
OIT-45 Biocide should be directly dispensed into metalworking fluid concentrates or use-dilution metalworking fluids using a metering pump or other point-of-use device where possible and uniformly dispersed throughout the fluid.
Fluid Concentrate
OIT-45  Biocide should be added to metalworking fluid concentrates at a level that ensures the final use-dilution fluid will contain 55 to 167 ppm of product (25 to 75 ppm active ingredient). OIT-45 stability in a given concentrate should be determined prior to commercialization. Contact your local Dow representative for assistance in selecting one of several recommended stabilizers to enhance the performance and compatibility of OIT-45 in your metalworking fluid concentrate.
Use-Dilution Fluid
We highly recommend grossly contaminated systems be cleaned before treatment is begun.
Initial Dose: For a noticeably fouled system, add 0.47 to 1.44 lbs (7 to 21 fl oz) of OIT-45 Biocide per 1,000 gallons of fluid. This will provide 25 to 75 ppm active ingredient. Repeat until control is achieved.
Subsequent Dose: For maintenance of a non-fouled system, add 0.09 to 0.58 lbs (1.3 to 8.6 fl oz) of OIT-45 Biocide per 1,000 gallons of fluid every four weeks. This will provide 5 to 30 ppm active ingredient. A higher dose range and/or increased frequency of treatment may be required, depending upon the rate of dilution of the preservative with the makeup fluid, the nature and severity of contamination, level of control required, filtration.


25Kg per drum, 200Kg per drum or 1000Kg per IBC drum.