720 ILCS 5/4-9

Absolute liability. A person may be guilty of an offense without having, as to each element thereof, one of the mental states described in Sections 4-4 through 4-7 if the offense is a misdemeanor which is not punishable by incarceration or by a fine exceeding $1,000, or the statute defining the offense clearly indicates a legislative purpose to impose absolute liability for the conduct described.