What types of emergency shower and eyewash units exist and how are they used?

• A. Self-contained units provide the best protection, while permanently installed units are for temporary use.
• B. Permanently-installed units are for temporary use, while self-contained are best.
• C. Permanently-installed units provide the best protection, while self-contained units are for temporary use.
• D. Either type provides equal protection, so choice doesn't matter.

Answer: (C)

The main idea here is that the level of protection and readiness of emergency shower and eyewash equipment depends on whether the unit is permanently installed or self-contained.

Permanently-installed units are fixed to the building’s plumbing, placed in a set location, and designed to provide a continuous, adequate flow for the full 15-minute flush without relying on a water reservoir. This makes them the most reliable option for sites with ongoing hazards or regular work operations, because maintenance, inspection, and immediate access are easier to manage, and the unit can deliver a consistent stream regardless of how long the incident lasts.

Self-contained units, by contrast, are portable and have their own built-in water supply. They’re ideal for temporary setups, remote locations, or places where plumbing isn’t feasible. They protect workers when a fixed system isn’t available, but they depend on the reservoir’s capacity and require regular refilling or replacement, so the available flush time and reliability can be limited compared to fixed installations.

Placed correctly near hazard areas and kept accessible, permanently-installed units provide the best protection, while self-contained units serve well when portability and lack of plumbing are essential.