CPT Safety Protocols & Hazard Management 3 — Questions and Answers
Question 1: Which tool is most commonly used during a Process Hazard Analysis (PHA) to systematically identify deviations from design intent?
- HAZOP (Hazard and Operability Study) (Correct answer)
- Fault Tree Analysis
- Bow-Tie Diagram
- Job Safety Analysis
Correct answer: HAZOP (Hazard and Operability Study)
HAZOP uses guide words (e.g., MORE, LESS, NO) applied to process parameters to identify deviations and their potential consequences.
Question 2: A process vessel is being prepared for maintenance entry. After blinding and purging, the confined space atmosphere tests at 20.8% oxygen and 0 ppm toxic gases. What should happen next?
- Issue the confined space entry permit and post an attendant (Correct answer)
- Allow immediate entry without further controls
- Re-purge for another hour before testing again
- Test for flammable gas only — oxygen testing is not required
Correct answer: Issue the confined space entry permit and post an attendant
Acceptable atmospheric conditions are necessary but not sufficient alone; a formal permit must be issued and an attendant stationed outside.
Question 3: What does 'inherently safer design' (ISD) mean in process safety?
- Eliminating or reducing hazards at the source rather than relying on controls (Correct answer)
- Adding more layers of engineered safety barriers
- Increasing operator training frequency
- Installing backup instrumentation systems
Correct answer: Eliminating or reducing hazards at the source rather than relying on controls
ISD reduces risk by minimizing inventory, substituting less hazardous materials, or simplifying processes so hazards cannot occur rather than just being controlled.
Question 4: Which of the following best describes the purpose of a safety shower and eyewash station in a chemical processing area?
- To flush corrosive or hazardous chemicals from the body or eyes immediately after contact (Correct answer)
- To decontaminate PPE before reuse
- To provide potable water for workers in remote areas
- To test water quality before process use
Correct answer: To flush corrosive or hazardous chemicals from the body or eyes immediately after contact
Safety showers and eyewashes provide immediate, high-volume water flushing to minimize injury from chemical exposure within 10 seconds of exposure.
Question 5: In the hierarchy of controls, which control measure is considered MOST effective for managing workplace hazards?
- Elimination of the hazard (Correct answer)
- Engineering controls
- Administrative controls
- Personal protective equipment
Correct answer: Elimination of the hazard
Elimination removes the hazard entirely and is the most reliable because it does not depend on human behavior or equipment maintenance.
Question 6: A pressure relief valve (PRV) on a reactor has been found leaking slightly. What is the correct immediate action?
- Tag the valve, notify supervision, and follow the Management of Change procedure (Correct answer)
- Tighten the valve seat by hand to stop the leak
- Remove the PRV immediately to inspect the seat
- Bypass the PRV with a block valve to prevent release
Correct answer: Tag the valve, notify supervision, and follow the Management of Change procedure
A leaking PRV must be documented, supervision notified, and MOC procedures followed before any modification, as the PRV is a critical safety device.
Question 7: Which GHS (Globally Harmonized System) pictogram indicates an acute toxicity hazard?
- Skull and crossbones (Correct answer)
- Exploding bomb
- Flame over circle
- Exclamation mark
Correct answer: Skull and crossbones
The skull and crossbones pictogram on a GHS Safety Data Sheet indicates acute toxicity categories 1–3, meaning small amounts can be fatal.
CPT Safety Protocols & Hazard Management 3
Which tool is most commonly used during a Process Hazard Analysis (PHA) to systematically identify deviations from design intent?