In the pedicure chair hazard, the backflow preventor should be which of the following?

• A. Atmospheric vacuum breaker
• B. Double check valve
• C. Reduced pressure principle backflow preventor
• D. Pressure reducing valve

Answer: (C)

Backflow prevention in a pedicure chair must guard against both backsiphonage and backpressure, since wastewater from the foot basin can contaminate the potable water supply. The reduced pressure principle backflow preventer provides the highest level of protection for this high-hazard cross-connection. It uses two independent check valves with a reduced-pressure zone between them and a relief port to atmosphere, so if either check valve leaks or pressure in the supply side drops, contaminated water cannot be drawn back into the system. This robust design is specifically intended for situations like foot spas where toxic or hazardous substances could be present, and it typically requires periodic testing to ensure it remains effective.

Other devices don’t offer the same level of protection in this context. An atmospheric vacuum breaker relies on atmospheric venting and is vulnerable to backpressure and improper installation, making it unsuitable for continuous, pressurized spa systems. A double check valve provides some protection but lacks the additional safeguard of a relief port and can be less reliable if a valve leaks. A pressure reducing valve merely lowers supply pressure and does not prevent backflow at all.