Which decontamination category focuses on achieving contamination levels equal to natural background in the least possible remaining amount?

• A. Routine
• B. Partial
• C. Thorough
• D. Emergency

Answer: (C)

Thorough decontamination aims to remove contaminants as completely as possible, ideally bringing levels down to natural background with only trace residues remaining. This approach uses a systematic, multi-step cleaning process, careful verification (like wipe tests or measurements), and proper disposal of contaminated waste to ensure nearly all contamination is eliminated. In contrast, routine decontamination is more basic and only seeks enough cleaning to proceed with operations safely, partial decontamination represents an intermediate effort with more residual contamination, and emergency decontamination focuses on rapid exposure reduction in urgent situations, which may not achieve background-level cleanliness.