FORD 2010 Flex v.2 - Manual (Page 215)

For proper care of soiled safety belts, refer to Interior in the Cleaning
chapter.
WARNING: Failure to inspect and if necessary replace the
safety belt assembly or child restraint system under the above
conditions could result in severe personal injuries in the event of a
collision.
Seating and Safety Restraints
215
2010 Flex (471)
Owners Guide, 2nd Printing
USA (fus)