OAR 340-256-0110: Visible Emissions: Special Requirements for Excluded Motor Vehicles

A person may not operate, drive, or cause or permit to be driven or operated upon a public street or highway, any motor vehicle excluded from OAR 340-256-0100 that: (1) When operated at an elevation of 3,000 feet or less, emits visible emissions into the atmosphere: (a) Of an opacity greater than 10 percent; or (b) Of an opacity 40 percent or greater for a period exceeding seven consecutive seconds. (2) When operated at an elevation over 3,000 feet, emits visible emissions into the atmosphere: (a) Of an opacity greater than 20 percent; or (b) Of an opacity of 60 percent or greater for a period exceeding seven consecutive seconds.