What is the correct flow direction through the CBRN decontamination corridor?

• A. Flow from hot to cold.
• B. Flow from cold to hot.
• C. Flow in a circular sequence.
• D. Flow direction is random.

Answer: (A)

In a CBRN decontamination setup, the goal is to remove contamination before people or gear enter safe, clean areas. That means moving from the contaminated area through the decon steps and toward the clean area, so the flow direction is hot to cold. Starting in the hot zone and progressing to the cold zone ensures contaminants are shed and contained at each stage, reducing the chance of recontaminating anything in the clean zone and keeping exposure under control.

Flowing from cold to hot would push someone into a contaminated space first, increasing the risk of spreading contaminants. A circular sequence or a random flow doesn’t provide a controlled, stepwise decontamination path, which could allow contaminants to linger or move back into clean areas.