Fluorescent Yellow 131 SC


FLUORESCENT YELLOW 131SC is a concentrated solvent soluble dye containing Solvent Red 175 in a high flash hydrotreated naphthenic solvent system. The product is a dark colored liquid and is completely miscible in most petroleum or organic based products. The solvent is used in the product as a viscosity depressant and standardizing agent.
leaking engine oil fluorescent

Fluorescent Yellow 131SC is designed to easily find and spot leaks in hydraulic systems, engine blocks, oil filled heat exchangers, improperly seated gaskets, and any other leak detection application that requires the use of petroleum based fluids. Fluorescent Yellow 131SC can also be used for fuel pipeline applications to clearly identify a changeover from one fuel type to another.


FLUORESCENT YELLOW 131SC can be used for detecting oil leaks in gasoline and diesel engines. This application requires addition of the fluorescent dye to the engine oil and subsequent examination of the engine using a high intensity black light. Leaks are easily detected with this system by the intense white-yellow fluorescence of the dye. This fluorescence is readily distinguished from the natural blue fluorescence found in some oils.


Introduction of the dye into the engine can be carried out in one of two ways. Engine oil and dye may be premixed and added to the engine prior to the engine test or dye may be added to the engine after the oil fill by adding the dye directly into the engine sump. Leakage is monitored during and after the "hot-cell" test or after the dynometer test by examining the engine with a high intensity black light (100-125 W emitting at 365 nm). Leakage is readily detected by the presence of a white-yellow fluorescence caused by the presence of the dye.


The following recommendations are provided as a starting point for typical applications. Actual dosage will depend on desired color strength as well as background color of the base material.

Hydraulic & Transmission Fluids
500 to 2000 ppm

Car Engine Oils
500 ppm

Diesel Engine Oils
700 to 2000 ppm
Contact Us
close slider
Contact Us
Please provide a daytime number where we can reach you.