The useful starting point
Classify what the proposal actually changes, identify whose exposure remains, and separate a promising idea from a verified control.
Use the hierarchy as a question sequence
CCOHS presents elimination, substitution, engineering controls, administrative controls and personal protective equipment as a hierarchy. It also emphasizes checking whether controls work and whether a change introduces other hazards. A category name alone does not establish that a particular proposal is suitable.
For study, ask two questions about every option: what changes physically or organizationally? and which exposure remains? That makes it easier to distinguish a real change to the source from a reminder to behave differently around it.
The fictional cutting-station case
A training case describes a workshop cutting components beside a packing desk. The case says noise from the cutting task affects people at the desk. It provides no measured levels, equipment specifications, duration, materials or specialist assessment. Your task is to classify proposals and identify questions, not approve equipment or select hearing protection.
The purchasing coordinator suggests ordering components already cut to size. Another learner suggests a quieter process. The maintenance lead suggests a designed enclosure. A supervisor suggests a schedule change, and someone else suggests hearing protection. These proposals change different parts of the story.
Compare proposals rather than buzzwords
| Proposal in this example | Likely category | Question still to resolve |
|---|---|---|
| Remove the on-site cutting task by buying finished components | Elimination of this local task and source | Does the revised workflow introduce different hazards? |
| Replace the process with a demonstrably less noisy alternative | Substitution | What evidence supports the comparison under actual use? |
| Have a suitable enclosure designed for the source | Engineering | Does it control exposure while accounting for access and other hazards? |
| Change the timing of packing activity | Administrative | Who remains exposed during cutting? |
| Use selected hearing protection | PPE | What assessment and protection program support selection and use? |
Keep the scope of each claim narrow
The first proposal removes the cutting activity from this workshop. It does not prove that the supplier has no cutting hazards, that deliveries are risk-free or that the new components suit production. “Elimination” needs an object: which hazard or exposure is eliminated, for whom, and within what boundary?
The schedule proposal may change exposure for packing staff while leaving the cutting operator exposed. Calling it administrative is correct, but stopping at that label misses the main issue. In a written explanation, name the people the proposal helps and the people it does not yet address.
Defend your answer with the actual wording
Imagine an answer choice says, “Install a warning sign, which removes the noise source.” The mismatch is between the action and the claimed effect. The sign does not describe a change to the source. You can reject that explanation without pretending to know a measured noise level.
For each future practice question, underline the action verb: remove, replace, isolate, schedule or wear. Then check the whole sentence before deciding. Several controls may appear together, and a question may ask about only one part. Use the hazard-assessment practice page to rehearse that distinction.
Check your reasoning.
A learner says moving packing staff to another time slot eliminates the cutting hazard. What is the more precise explanation?
Open the suggested reasoning
The proposal changes when packing staff are exposed; it does not remove the cutting task or establish protection for the cutting operator. In this scenario it is an administrative proposal whose effectiveness still needs assessment.
An original learning exercise from NCSO Prep, not an official exam question.
Sources and scope
Source review: . The examples and study methods are NCSO Prep editorial material. Official requirements and workplace decisions must be checked against the applicable current source.
- CCOHS: Hierarchy of Controls
Control categories and the need to evaluate effectiveness and new hazards. Reviewed October 18, 2026.