How should multiple contamination markings be placed?

• A. Spaced widely
• B. Adjacent to each other
• C. In a grid with gaps
• D. Randomly

Answer: (B)

Contamination markings work best when related marks are placed together so responders can quickly see the full extent of the contaminated area. Placing them adjacent communicates that all the items or spots in that nearby cluster are part of the same zone, making it easier to isolate, decontaminate, and prevent spread. If marks were spaced widely, it could imply separate or unrelated contaminated spots, creating confusion and increasing risk. A grid with gaps can also mislead about where the contamination actually lies or how far it extends, and random placement would be unpredictable and hard to interpret in an emergency. Keeping multiple contamination marks together provides clear, immediate visual information about the scope of contamination.