What distinguishes primary (gross) decontamination from secondary decontamination during a CBRN incident?

• A. Secondary decon occurs at the point of exposure for rapid reduction
• B. Primary decon occurs at the point of exposure for rapid reduction; secondary decon occurs later in controlled areas for thorough removal before re-entry or custody
• C. Decon is optional and not required
• D. Secondary decon occurs before exposure

Answer: (B)

The important distinction is timing and purpose: primary (gross) decontamination is done at the exposure point to rapidly reduce surface contamination right away, limiting dermal uptake and spread as the incident unfolds. Secondary decontamination happens later in controlled areas and uses more thorough cleansing to remove residual contamination before people re-enter clean zones or are handed over to authorities or medical facilities. This staged approach ensures quick reduction of contamination on-site, followed by a thorough finish in a protected environment to prevent cross-contamination and ensure safe transfer or custody.