Outline the general hierarchy of controls for chemical hazards.

• A. Elimination/substitution, engineering controls (ventilation/containment), administrative controls (training, scheduling), and PPE (gloves, respirators).
• B. PPE, administrative, engineering, elimination.
• C. PPE only.
• D. Administrative controls only.

Answer: (A)

The hierarchy of controls ranks methods for reducing chemical exposure by how reliably they remove or contain the hazard. The most effective approach is elimination or substitution—if you can remove the chemical entirely from the process or replace it with a less hazardous substance, worker exposure is addressed at the source. Next are engineering controls, which physically limit exposure, such as using enclosed processes, local exhaust ventilation, or fume hoods to capture vapors before they reach workers. If full elimination or engineering controls aren’t feasible, administrative controls come into play, changing how work is done through procedures, training, scheduling, rotation to limit exposure time, and clear work practices to minimize risk. PPE is the last line of defense, providing a barrier between the worker and the hazard, but it relies on proper selection, use, fitting, and maintenance, and it does not reduce the hazard itself. In practice, designers combine these layers, prioritizing elimination and engineering controls first, then administrative measures, and using PPE to complement the others when needed.