The decontamination of crew members in an incident involving anhydrous ammonia by water and soap is known as what?

• A. Sorption
• B. Filtration
• C. Dilution
• D. Neutralization

Answer: (C)

Removing a chemical contaminant from a person with water and soap relies on dilution and physical removal. Washing with water rinses away ammonia residues, and the soap helps lift and remove those residues more effectively by reducing surface tension and emulsifying oily parts of the contaminant. This lowers the amount of contaminant on the skin and clothing, reducing exposure risk. The other ideas describe different processes: binding the contaminant to a surface (sorption), filtering it out (filtration), or driving a chemical reaction to neutralize it (neutralization). None of those describe the straightforward act of washing someone off with soap and water, which is why dilution is the correct concept.