Zone 3: Cold Zone

The support (cold) zone is the outermost part of the site, and is considered a non-contaminated or clean area. Support equipment (command post, equipment trailer, etc.) is located in this zone and traffic is restricted to authorized response personnel.

Since normal work clothes are appropriate within this zone, potentially contaminated personnel clothing, equipment, and samples are not permitted, but are left in the warm zone until they are decontaminated.

The command post is always located in the support (cold) zone and should serve as the communication center for all on site and off site activities relative to the operation. The location of the command post and other support facilities in the cold zone depends on a number of factors, including:


  • Land surface characteristics
  • Open space availability
  • Locations of highways, railroad tracks
  • Other limitation

Wind direction

  • The support facilities should always be located upwind of the Hot zone.
  • However, shifts in wind direction and other conditions may be such that an ideal location based on wind direction alone does not exist.


  • Adequate roads, power lines, water and shelter