The following work must be completed prior to flush-out or testing to ensure that the air quality isn't compromised afterward.

All interior finishes must be installed.
All punch-list items must be complete. 
All cleaning must be finalized.
Final testing and balancing of HVAC systems must be complete. Other commissioning tasks can occur during flush-out or testing only if they do not introduce any additional contaminants into the building.
Temporary filters and duct coverings used as part of the construction IAQ management plan must be removed.
Filters must be replaced with new filtration media, unless the system is configured to filter only outside air. If your project is pursuing IEQc5: Indoor Chemical and Pollutant Source Control, these filters must be MERV 13 or higher.
For BD&C projects, it is optional to install furniture and furnishings prior to testing or flush-out. For ID&C projects, movable furnishings must be installed prior to testing or flush-out.