321.460  Spilling loads on highways.
  A vehicle shall not be driven or moved on any highway by any person unless such vehicle is so constructed or loaded or the load securely covered as to prevent any of its load from dropping, sifting, leaking, or otherwise escaping or its load covering from dropping from the vehicle, except that sand may be dropped for the purpose of securing traction, or water or other substance may be sprinkled on a roadway in cleaning or maintaining such roadway. The provisions of this section shall not apply to vehicles loaded with hay or stover or the products listed in section 321.466, subsections 5 and 6.
[C39, §5035.09; C46, 50, 54, 58, 62, 66, 71, 73, 75, 77, 79, 81, §321.460]

For applicable scheduled fine, see §805.8A, subsection 13, paragraph c