With the signing of Public Act 91-173, the Dyed Diesel program in Illinois became effective January 1, 2000. Aligning Illinois' program with the Federal dyed diesel/low sulfur program, Illinois law now requires that all special fuel used for non-taxable, non-highway use must have red dye added. The dye provides the identifier which serves as an enforcement tool during field audits and inspections.
The importance of this program is recognized and supported by the motor fuel industry as it serves to "level the playing field" and enhance compliance in an industry vulnerable to tax-evading schemes. Funding secured from the Illinois Department of Transportation, the Illinois State Police, and the Illinois Commerce Commission to purchase vehicles and testing, sampling, and safety equipment, has allowed IDOR to enforce this program.
What is dyed diesel?
Dyed diesel is any special fuel that has dye added per Section 4d of the Motor Fuel Tax Law. Basically, it's any diesel fuel with any amount of dye present.