Disinfection in ambulance decontamination often uses a chemical mixture of bleach and water at what ratio?

• A. 1:10
• B. 10:1
• C. 1:1
• D. 1:100

Answer: (A)

Disinfection using bleach works best when the solution is strong enough to inactivate germs but not so strong that it harms people or surfaces. For ambulance decontamination, a common practical dilution is one part bleach to ten parts water. This creates about 0.5% sodium hypochlorite, which is effective for general surface disinfection when the surface remains wet for a short contact time (often a minute or two, longer for tougher residues). A much stronger mix would be unnecessarily caustic and hazardous, while a weaker mix would not reliably disinfect. Always follow local protocols for contact time and safety when using bleach-based disinfectants.