Dye: Yellow F4 Fluorescent Dye
Yellow F4 fluorescent dye can be used to trace a leak in any system which contains a petroleum product (all oils, greases, fuels). It fluoresces a yellow/green color when exposed to a UV light (black light) . A typical mix ratio is 7 ounces of dye to 100 gallons of oil. Sold in pints, quarts, gallons, and 5 gallon pails. You can not see the dye unless it is exposed to UV light.