A plumber is installing a bidet seat on an existing toilet in a residential bathroom. The client wants to ensure that the cold water supply to the bidet attachment has appropriate backflow prevention. What is the most suitable type of backflow prevention device to install for this application, as per typical plumbing codes?

Question: A plumber is installing a bidet seat on an existing toilet in a residential bathroom. The client wants to ensure that the cold water supply to the bidet attachment has appropriate backflow prevention. What is the most suitable type of backflow prevention device to install for this application, as per typical plumbing codes?

Answer options:

• Double check valve assembly (DCVA)
• Reduced pressure principle assembly (RPPA)
• Atmospheric vacuum breaker (AVB) ✅ Self-contained fixture integral backflow preventer.

Correct answer: Self-contained fixture integral backflow preventer.

Explanation: For bidet seats and similar fixtures with a potential cross-connection to a potable water supply, a self-contained fixture integral backflow preventer (often a vacuum breaker or check valve built into the fixture or supply fitting) is typically sufficient and code-compliant. DCVAs and RPPAs are for higher-risk cross-connections, and while an AVB could technically work, integral prevention is more common for this specific fixture type.