Reduce the accidental spread of hazardous substances by workers or equipment from the
contaminated areas to the clean areas;
Confine work activities to the appropriate areas, thereby minimizing the likelihood of
Facilitate the location and evacuation of personnel in case of an emergency; and
Prevent unauthorized personnel from entering controlled areas.
When establishing the work zones at a site, the site map can provide a useful format for compiling
the relevant data. In the absence of sampling results, site maps can provide essential information
on potential and suspected hazards and potential exposure pathways.
Although a site may be divided into as many zones as necessary to ensure minimal employee
exposure to hazardous substances, the three most frequently identified zones are the Exclusion
Zone (or "hot zone"), the Contamination Reduction Zone, and the Support Zone (or "clean
zone"). Movement of personnel and equipment between these zones should be minimized and
restricted to specific access control points to prevent cross-contamination.
9.3.1. The Exclusion Zone
The Exclusion Zone is the area where contamination is either known or expected to occur and
where the greatest potential for exposure exists. The outer boundary of the Exclusion Zone,
called the Hotline, separates the area of contamination from the Contamination Reduction Zone.
The Hotline should initially be established by visually surveying the site and determining the
extent of hazardous substances, discoloration, or any drainage, leachate, or spilled material
present. Other factors to consider in establishing the Hotline include:
Providing sufficient space to protect personnel outside the Exclusion Zone from potential
fire or explosion,
Allowing an adequate area within which to conduct site operations, and
Reducing the potential for contaminant migration.
The Hotline should be physically secured (e.g., using chains, fences, or ropes) or clearly marked
(e.g., using lines, placards, hazard tape, and/or signs). During subsequent site operations, the
boundary may be modified and adjusted as more information becomes available. In addition, the
Exclusion Zone may also be subdivided into different areas of contamination based on the known
or expected type and degree of hazards or the incompatibility of waste streams. If the Exclusion
Zone is subdivided in this manner, additional demarcations (e.g., "Hazards Present" or
"Protection Required") may be necessary. For sites where radiological contamination exists,
procedures for establishing and posting of radiological zones should be developed and included
in this chapter. Procedures should be in accordance with the DOE Radiological Control Manual.
Access to and from the Exclusion Zone should be restricted to Access Control Points at the
Hotline. Access Control Points are used to regulate the flow of personnel and equipment into