High-Frequency Concepts in the CRSP & CRST Exam
What terminology and topics should you expect to see? This page covers concepts that commonly appear on CRSP and CRST certification exams. Each concept includes a brief description and an explanation of why it gets tested.
How to use this page
These concepts have a high chance of showing up — but not all of them will appear on your specific exam. Every exam is different.
This is not a complete list. The CRSP and CRST exams cover far more than what’s listed here. These are high-frequency patterns, not a guarantee of coverage.
Knowing only these concepts is not enough to pass. They are a starting point for recognition, not a replacement for comprehensive study. Use this page to check whether you can quickly explain each term — if you can’t, that’s a study gap to close.
- What this page does: Helps you recognize common terminology and understand why each concept is tested.
- What this page does NOT do: Predict specific questions, provide enough material to pass on its own, or replace textbook study.
01 Legal & Regulatory Foundations
The legal framework that defines who is responsible for what — and what happens when things go wrong.
Internal Responsibility System (IRS)
A Canadian regulatory principle where everyone in the workplace shares responsibility for health and safety according to their role and authority. The employer has the greatest responsibility because they control resources, conditions, and systems.
Questions often ask "who bears the greatest responsibility?" — the answer is the employer. IRS also underpins worker rights and JHSC requirements.
Three Rights of Workers
Workers in Canada have three fundamental rights: the right to know about workplace hazards, the right to participate in safety decisions (via JHSCs), and the right to refuse unsafe work without reprisal.
Tested as a foundational knowledge question. Often appears when a scenario involves imminent danger — the right to refuse becomes the correct answer.
TLV vs OEL
TLV (Threshold Limit Value) is a guideline set by ACGIH (a private organization). OEL (Occupational Exposure Limit) is set by provincial/federal governments and is legally enforceable.
Tests whether you know which is legally enforceable. Common trap: assuming TLV is law. TLV is guidance; OEL is law.
Due Diligence
The legal standard requiring employers to take all reasonable steps to identify hazards, prevent harm, and respond to incidents — proportionate to the foreseeable risk. It’s a defence against charges, not a guarantee of immunity.
Tested in legal/ethics scenarios. The key phrase is “all reasonable precautions.” Due diligence is proven by documentation, training records, and demonstrated effort.
Reasonable Person Test
An objective legal standard asking: would a reasonable person in the same circumstances have acted the same way? Used in negligence cases and due diligence defences.
Tests legal reasoning. Often appears as “what is the Reasonable Person Test used for?” Answer: to determine if actions were negligent.
BCRSP Code of Ethics
The professional conduct standard for CRSP and CRST certificants. Key principle: public safety takes priority over employer interests when life is at risk.
Tested in ethical dilemma scenarios. If the employer tells you not to report a life-threatening hazard, you report it anyway — ethics and law require it.
02 Hazard ID & Risk Methods
How hazards are identified, analyzed, and controlled — and what order to do it in.
Job Hazard Analysis (JHA / JSA)
A task-based technique that breaks a job into sequential steps, identifies hazards at each step, and specifies controls. Also called Job Safety Analysis (JSA) or Task Safety Analysis (TSA).
Very common on CRST. Tests the correct order: select job → break into steps → identify hazards → develop controls → communicate. Trap: confusing JHA (task-level) with HAZOP (process-level).
Task Analysis vs JHA
Task Analysis observes how workers actually perform tasks (actions, behaviors, perceptions). JHA identifies hazards at each step. They are related but not the same.
Tests your ability to distinguish similar tools. Task Analysis = “what do workers do?” JHA = “what hazards exist at each step?”
Hierarchy of Controls
The 5-level prioritization for controlling hazards, ranked most to least effective: Elimination → Substitution → Engineering → Administrative → PPE.
The single most-tested concept across both exams. Always select the highest feasible level. PPE is last resort. Trap: choosing PPE because it’s “cheapest and fastest.”
Management of Change (MOC)
A formal process requiring hazard assessment whenever there is a change to equipment, processes, materials, or personnel. New equipment cannot be used until MOC is complete.
Tests whether you know that change triggers reassessment. Common stem: “new equipment introduced — what is required before use?” Answer: hazard assessment.
ALARP vs ALARA
ALARP (As Low As Reasonably Practicable) — reduce risk until further reduction is grossly disproportionate to benefit. ALARA (As Low As Reasonably Achievable) — same principle, often used in radiation contexts.
Tests understanding that zero risk is not the goal — reasonable reduction is. ALARP is UK/Canada terminology; ALARA is radiation-specific.
03 Industrial Hygiene Terminology
Exposure limits, measurement concepts, and the language of occupational health.
TWA, STEL, and Ceiling
TWA (Time-Weighted Average) = average exposure over 8 hours. STEL (Short-Term Exposure Limit) = 15-minute average, max 4 times per day. Ceiling = never-exceed limit.
Very common on CRST. Tests whether you know what each limit type means and when to use each. Trap: confusing STEL (15-min) with Ceiling (never-exceed).
8-Hour TWA Calculation
Calculated by integrating all exposure concentrations over the work shift, weighted by time at each concentration. Formula: Σ(C × T) ÷ 8 hours.
May appear as a calculation question or conceptual question about how TWA is determined. Key: it’s time-weighted, not a simple average of readings.
Routes of Entry
How chemicals enter the body: inhalation (most common), skin absorption, ingestion, and injection (needle stick, high-pressure equipment).
Tests basic toxicology knowledge. Inhalation is the most common route in occupational settings. Skin absorption is often underestimated.
Acute vs Chronic Exposure
Acute = short-term, high-concentration exposure with immediate effects. Chronic = long-term, repeated low-level exposure with delayed effects.
Tests understanding of exposure duration vs concentration. Occupational disease (chronic) is often more deadly than acute incidents over a career.
BEI vs TLV
TLV measures airborne concentration. BEI (Biological Exposure Index) measures the substance or metabolite in the worker’s body (blood, urine, exhaled air) — capturing total exposure from all routes.
Tests understanding that BEI captures skin and ingestion exposure that air monitoring misses. Key advantage of biological monitoring.
04 Ventilation & Air Quality
How airborne contaminants are controlled — at the source or by dilution.
LEV vs Dilution Ventilation
Local Exhaust Ventilation (LEV) captures contaminants at the source before they disperse. Dilution (general) ventilation mixes contaminated air with clean air to reduce concentration. LEV is more efficient.
Tests hierarchy understanding. LEV is the preferred engineering control because it prevents exposure entirely. Dilution is acceptable only when LEV is impractical.
| LEV (Local Exhaust) | Dilution Ventilation |
|---|---|
| Captures at source | Mixes with room air |
| More efficient, less air volume | Less efficient, more air volume |
| Prevents worker exposure | Reduces concentration only |
| Preferred for toxic/high-hazard | OK for low-hazard, dispersed sources |
ACH (Air Changes per Hour)
Measures how many times the total air volume in a space is replaced in one hour. Higher ACH = better dilution of airborne contaminants.
Tests ventilation terminology. May appear as “what does ACH stand for?” or as part of an IAQ question.
Indoor Air Quality (IAQ) & Mold
Mold and inadequate ventilation are the most common causes of IAQ complaints in commercial buildings. Symptoms are often non-specific (headaches, fatigue, irritation).
Tests practical knowledge. First action when mold is discovered: restrict access to the affected area before sampling or remediation.
05 Monitoring Instruments
The tools used to measure workplace hazards — and which one to use when.
Noise Dosimeter vs Sound Level Meter (SLM)
Dosimeter is worn by the worker and measures cumulative noise exposure over a shift (TWA, dose %). SLM measures point-in-time sound levels at a location.
Common question: “what instrument measures personal noise exposure over an entire shift?” Answer: dosimeter, not SLM.
Qualitative vs Quantitative Fit Testing
Qualitative = pass/fail based on wearer’s detection of a test agent (saccharin, Bitrex). Quantitative = numerical fit factor measured by instrument. Both must be done annually.
Tests respirator program knowledge. Key facts: two types, annual frequency, and that quantitative provides a numeric result.
Film Badge (Radiation Dosimetry)
A passive device containing photographic film that darkens when exposed to ionizing radiation. Provides a permanent record of cumulative radiation dose over the wear period.
Tests radiation monitoring knowledge. Key: film badge is for ionizing radiation (X-rays, gamma), not non-ionizing (RF, microwaves).
06 Physical Hazards
Radiation, heat, pressure, electricity, and fire — the energy-based hazards.
Ionizing vs Non-Ionizing Radiation
Ionizing (X-rays, gamma, alpha, beta) has enough energy to remove electrons from atoms — causes cell damage and cancer. Non-ionizing (RF, microwaves, visible light, UV) lacks this energy.
Tests basic physics knowledge. Common question: “microwaves and visible light are what type of radiation?” Answer: non-ionizing.
Heat Stress & Core Temperature
Heat-related illness becomes a serious concern at approximately 40°C body core temperature. Symptoms progress from heat rash to heat exhaustion to heat stroke.
Tests recognition of heat stress thresholds. WBGT is the environmental measurement; core temperature is the physiological concern.
Electric Arc
Occurs when electrical current jumps through air, ionizing air molecules and creating plasma. Can reach 35,000°F and cause severe burns, blast injuries, and radiation damage.
Tests electrical safety knowledge. Key: arc flash is an ionization event, not just a spark. Requires arc-rated PPE and safe work distances.
Hot Work
Work that produces heat, sparks, flames, or ignition sources capable of igniting flammable materials. Includes welding, cutting, grinding, and brazing.
Tests permit-required work knowledge. Trap: assuming “hot work” means work in hot temperatures. It refers to ignition sources, not ambient heat.
Pressure Vessel Hydrostatic Testing
Pressure vessels must be hydrostatically tested at 1.5 times (150%) the MAWP (Maximum Allowable Working Pressure). Water is used because it’s nearly incompressible, making failures safer.
May appear as a numeric recall question. The ratio 1.5× MAWP is a common standard (CSA B51, ASME BPVC).
Carbon Monoxide (Chemical Asphyxiant)
CO binds to hemoglobin 200–250× more strongly than oxygen, forming carboxyhemoglobin and preventing oxygen delivery to tissues. It’s a chemical asphyxiant, not a simple asphyxiant.
Tests toxicology knowledge. Key distinction: chemical asphyxiant (interferes with oxygen transport) vs simple asphyxiant (displaces oxygen in air).
07 Safety Systems & Investigation
Inspections, audits, incident investigation — the management side of safety.
Inspection vs Audit
Inspection examines physical workplace conditions and worker practices for specific hazards. Audit examines the entire safety management system for effectiveness and compliance.
Very common distinction question. Inspection = physical conditions. Audit = management system.
| Inspection | Audit |
|---|---|
| Physical conditions & practices | Management system effectiveness |
| Specific hazards | Overall compliance |
| Frequent (daily/weekly/monthly) | Periodic (annual/biannual) |
| Done by supervisors, workers, JHSC | Done by trained auditors |
Audit Triangle (Data Collection Methods)
The three core audit data collection methods: document review, interviews, and observation. These allow auditors to triangulate findings.
Tests audit methodology knowledge. Common question: “what are the three primary methods of data collection during an audit?”
Incident Investigation: First Action
After an incident (e.g., fire extinguished), the first step is to secure and preserve the scene — protect evidence, restrict access, ensure the area is safe before investigation begins.
Tests priority thinking. Trap: choosing “interview witnesses” or “take photographs” as first step. Scene preservation comes first.
Safety Signage Colors
Red = danger, fire protection, stop, emergency. Yellow = caution. Orange = warning (machine hazards). Green = safety equipment, first aid. Blue = information, mandatory action.
Tests basic safety communication knowledge. May appear as “what does the color RED signify?” Answer: danger, fire equipment, stop, emergency.
Workplace Violence Definition
Under Canadian OHS legislation, workplace violence includes exercising physical force that causes or could cause injury, attempting to exercise such force, or making statements/behaviors reasonably interpreted as threats.
Tests legal definition. Key: it includes attempts and threats, not just actual physical contact. Differs from harassment (non-physical).
When you encounter a term you can’t immediately explain, that’s a study gap. Use this page as a checklist: go through each concept and ask yourself “can I explain this in one sentence?” If not, it’s worth reviewing before exam day.
Remember: recognition is not readiness
Being able to recognize these terms is a good start — but the exam tests application, not just recognition. You need to know when to apply each concept, how to distinguish similar concepts, and how to prioritize when multiple concepts apply.
For CRST candidates, many of these concepts appear as direct knowledge questions (“what is X?”, “what does Y stand for?”).
For CRSP candidates, these concepts are embedded in scenarios where you must choose the most relevant application of the concept, not just identify it.
Use this page to find your gaps. Then close them with deeper study.
Test whether you can apply these concepts
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