Which of the following best illustrates an engineering control?

• A. Guard rails installed to physically prevent exposure
• B. Administrative scheduling
• C. Training program
• D. Warning signs

Answer: (A)

Engineering controls are physical changes to the environment that remove or reduce exposure to a hazard. Guard rails installed to physically prevent exposure fit this because they create a barrier that stops workers from reaching a dangerous edge, removing the need for workers to act to stay safe. They permanently separate the worker from the hazard. In contrast, administrative scheduling, a training program, and warning signs are administrative or educational measures that rely on people to follow procedures, notice warnings, or change how work is done rather than removing the hazard itself. So the guard rails best illustrate an engineering control.