Barriers should be used to contain the spread of dust and other pollutants from the work area to other parts of the home.
A simple barrier consists of 6 mil poly sheeting taped over doors and other openings in the room. Poly sheeting should also be taped over any supply and return registers for the home's heating, cooling, or ventilation system which are in the room to avoid spreading the pollutants or contaminating the ducts. Having blocked off registers, you should be sure to provide ventilation for the area. An exhaust fan, with provision for make-up air, complements this strategy well.
For more information, see the discussion of ventilation containment strategies which create a pressure barrier to prevent the spread of pollutants.
Figure 1, from HUD's Lead Paint Safety: A Field Guide for Painting, Home Maintenance, and Renovation Work illustrates how a barrier can be created which still allows access into the room. Note that for high dust jobs, or when generating other pollutants such as paint fumes, you may want to seal the room off completely from the rest of the house (without access from the inside).
Use this style of barrier system to keep airborne dust from spreading to another rooom
Figure 1 - Barrier to prevent dust from entering another room
If a job creates extremely high amounts of dust (for example demolition or sanding drywall compound) or large amounts of dust in the air for more than short periods, the protective flap system shown above may not be sufficient to prevent dust from spreading beyond the work area.
For these types of jobs, a more protective system called "isolation" is needed so that dust does not spread beyond the work area. Isolation means that the work area is sealed with no direct access to pccupied areas of the home. Workers need to use an entrance that is separate from the occupants, until cleanup has been completed.