What is the portion of bleach to water for cleaning soiled areas in a classroom or group setting to kill Parvo?

• A. 1:30
• B. 1:10
• C. 1:40
• D. 1:100

Answer: (A)

Disinfecting surfaces contaminated with parvovirus requires a strong chlorine-based solution because the virus is extremely hardy in the environment, especially in group settings like classrooms. The recommended dilution is a 1:30 bleach solution—one part household bleach to thirty parts water. This concentration provides enough chlorine to inactivate parvovirus when surfaces stay wet for about ten minutes, giving the disinfectant time to work. Make sure to prepare a fresh solution daily, apply it to all contaminated areas (floors, toys, and other nonporous surfaces), and allow it to remain wet for the contact time. Use gloves, ensure good ventilation, and never mix bleach with ammonia or other cleaners. Dilutions that are weaker, such as 1:40 or 1:100, or a much stronger 1:10, are not as reliable for killing parvovirus.