A chemical hose station can backpressure the potable system and its protective device is unknown. What should occur before use?
- ALower the water-heater temperature
- BRely on the hose nozzle
- Identify the hazard level and install or restore the approved protection before use
- DAssume a check valve inside the faucet is sufficient for the described plumbing system and documented site conditions
Why C is correct
The best answer is: Identify the hazard level and install or restore the approved protection before use. Chemical exposure can contaminate the potable system through backsiphonage or backpressure. Protection must match the actual hazard and be installed, tested, and accessible as required; assumptions about an ordinary hose fitting are unsafe. The transferred field condition applies the same plumbing design, installation, service, or safety principle to a different project setting. The alternatives omit a prerequisite, conflict with the approved method, or fail to control the stated sanitation or physical hazard.