You’re ready for advancement. You’ve got construction experience, you’re moving into a supervisory role, and you know that OSHA 30 is the credential that proves you understand safety at a leadership level. But OSHA 30 is significantly more complex than OSHA 10. It’s not just “more of the same”—it covers regulations, safety program development, incident investigation, and advanced hazard analysis. Many supervisors feel overwhelmed by the breadth of topics. This guide breaks down what OSHA 30 actually covers, what types of questions you’ll face, and a proven study strategy that gets you to pass.
What Is OSHA 30? (The Executive Version)
OSHA 30-hour training is designed for supervisors, project managers, and safety leads who manage workers and are responsible for implementing safety programs. Unlike OSHA 10 (which teaches workers to recognize hazards), OSHA 30 teaches you to:
- Understand and apply OSHA regulations
- Inspect work sites for compliance
- Investigate incidents and identify root causes
- Develop and implement safety programs
- Manage workers and enforce safety rules
- Calculate risk and assess hazards deeply Time commitment: 30 hours minimum over 4+ calendar days (can stretch to 4-6 weeks if studying part-time). Validity: Lifetime from OSHA; however, employers often require 5-year refreshers.
OSHA 30: The Core Topics You’ll Be Tested On
OSHA 30 covers everything from OSHA 10 plus much deeper regulatory and supervisory content.
Part 1: Foundation Topics (Covered in OSHA 10 + Deeper)
These are mandatory topics every OSHA 30 course must include:
- Fall Protection (Much Deeper)
- OSHA 1926.501 and substandards
- Engineering and administrative controls
- Rescue procedures and planning
- How to develop a fall protection plan
- Common violations and how to avoid them
- Electrical Safety (Advanced)
- Hazard recognition (arc flash, electrocution, shock)
- Grounding systems and GFCI
- Working near power lines
- OSHA electrical standards (1926.403, etc.)
- PPE (New Focus on Program Development)
- Selecting appropriate PPE for hazards
- New Jan 2025 requirement: Proper fit for each worker
- Training and certification (fit-testing for respirators)
- Maintenance and replacement
- Hazard Communication (Compliance & Management)
- Developing a HazCom program
- Responsibilities for employers vs. manufacturers
- Training requirements
- SDS organization and access
- Excavation & Trenching (Competent Person Role)
- Identifying soil types
- Designing protective systems
- Competent person responsibilities
- Daily inspection and monitoring
- Struck-By & Caught-In Hazards
- Prevention strategies
- Equipment operation and control
- Housekeeping and traffic control
Part 2: Advanced Topics (OSHA 30 Only)
- OSHA Standards & Regulations
- How OSHA standards are written (General Duty Clause, specific standards)
- Understanding citations and penalties
- Mandatory vs. advisory regulations
- Job Site Safety Inspections
- How to conduct a thorough inspection
- What to look for (hazard recognition at supervisory level)
- Documentation and reporting
- How to write inspection reports
- Incident Investigation
- Root cause analysis methodology
- How to investigate accidents/near-misses
- Identifying contributing factors (not just immediate cause)
- Corrective action planning
- Safety Program Development
- Creating safety policies and procedures
- Job safety analysis (JSA) / Job Hazard Analysis (JHA)
- Training documentation and records
- Hazard assessment (identifying hazards in your workplace)
- Workers’ Rights & OSHA Enforcement
- Worker rights under OSHA
- Whistleblower protections
- OSHA inspection procedures
- How citations and fines work
- Advanced Hazard Analysis
- Hierarchy of controls (elimination → engineering → administrative → PPE)
- Risk assessment and prioritization
- Cost-benefit analysis of safety measures
- Record-Keeping & Compliance
- OSHA 300 Log (injury/illness records)
- Recording requirements (what counts as recordable?)
- Annual summary and posting
- Privacy considerations
- Additional Industry-Specific Topics
- Scaffolding (detailed requirements)
- Machinery and machine guarding
- Confined spaces
- Lockout/tagout (LOTO)
- Some courses include specialized modules (roofing, electrical, etc.)
Key Differences: OSHA 10 Questions vs. OSHA 30 Questions
OSHA 30 questions move beyond “recognize hazards” to “manage and solve safety problems.”
OSHA 10-Style Question (Recognition)
“A worker is standing on the top rung of a ladder. What’s the hazard?”
- No hazard; top rung is designed for standing
- Fall hazard; can lose balance
- Electrical hazard
- Both A and B Correct: B (This is about hazard recognition.)
OSHA 30-Style Question (Problem-Solving)
“As a site supervisor, you’ve identified that workers frequently stand on ladder top rungs despite training. What’s the BEST first step to correct this?”
- Fire the workers
- Conduct a root cause analysis to understand why they’re using ladders incorrectly
- Install guardrails everywhere to eliminate ladder use
- Increase citations for violations Correct: B (This requires understanding root cause, problem-solving, and supervisory thinking.)
Study Strategy for OSHA 30
OSHA 30 is longer and more complex, so you need a different approach than OSHA 10.
Phase 1: Assess Your Knowledge (Week 1)
Take a diagnostic or practice test to see which topics are weak. If you score:
- 85%+: You’re in good shape; focus on weak areas
- 70-85%: Review the core topics; then drill weak areas
- Less than 70%: Budget more time; plan 4-6 weeks of study
Phase 2: Study by Topic (Weeks 2-4)
Don’t try to absorb all 30 hours at once. Study one major topic per week:
- Week 1: Fall Protection (all variants, deep dive)
- Week 2: Electrical, Machinery, PPE
- Week 3: Excavation, Struck-By, Hazard Communication
- Week 4: OSHA Regulations, Inspections, Incident Investigation, Safety Programs For each topic:
- Read the course material
- Watch videos if available
- Take topic-specific quizzes (10-20 questions)
- Score 90%+ before moving on
Phase 3: Full-Length Practice Exams (Week 5)
Once you’ve covered all topics, take 2-3 full-length practice exams:
- Practice test 1: Score yourself; review weak areas
- Wait 2-3 days: Let brain consolidate learning
- Practice test 2: Score again; focus on remaining weak spots
- Final review: Study weak topics one more time
- Practice test 3: Final assessment (goal: 85%+)
Phase 4: Final Exam (Week 6)
By now, you’ve studied 4-6 weeks, taken 3 full-length exams, and reviewed weak areas. You’re ready.
Sample OSHA 30 Exam Questions
Question 1: Safety Program Development
Your company is developing a new safety program. According to OSHA, what’s the FIRST step in developing an effective program?
- Assign a safety officer
- Conduct a comprehensive hazard assessment of the workplace
- Purchase safety equipment
- Conduct safety training Correct: B Why: You must first identify hazards before you can address them. This is foundational to program development.
Question 2: Root Cause Analysis
- After an electrical incident where a worker received a shock, you investigate and find that:
- The circuit breaker was overloaded
- The worker didn’t use proper PPE
- The area lacked GFCI protection Which is the ROOT CAUSE you should address to prevent similar incidents?
- Worker failed to use PPE (blame the worker)
- Lack of GFCI protection in the area
- Overloaded circuit breaker
- Inadequate training Correct: B (or C) Why: Lack of engineered controls (GFCI) is the root cause. PPE is the last line of defense. Fixing the engineering (GFCI) prevents the hazard entirely.
Question 3: OSHA Regulations
Which of the following best describes the OSHA General Duty Clause?
- Employers must eliminate all possible hazards
- Employers must provide a workplace free of recognized serious hazards
- OSHA must approve all hazard correction methods
- Workers must report all hazards immediately Correct: B Why: The General Duty Clause (Section 5(a)(1) of the OSH Act) is OSHA’s catch-all requiring safe workplaces even when no specific standard exists.
Question 4: Incident Investigation
- You’re investigating a trenching incident where a worker was trapped when the trench wall collapsed. You find:
- No trenching permit was issued
- No competent person was assigned
- No shoring/sloping was used What should be your first corrective action?
- Retrain workers on trenching safety
- Stop all trenching work until a competent person and protective system are in place
- Issue workers warning citations
- Increase trenching equipment maintenance Correct: B Why: Stop the hazard immediately. Root cause is lack of engineered controls (shoring/sloping) and competent person oversight. Training alone won’t fix the fundamental structural hazard.
Question 5: Job Hazard Analysis (JHA)
A JHA (Job Hazard Analysis) is most useful for:
- Determining OSHA compliance
- Breaking down a task into steps and identifying hazards at each step
- Training workers after an injury
- Calculating fines for violations Correct: B Why: A JHA systematically examines each step of a task to identify hazards and control measures. It’s a planning tool for supervisors.
Critical Topics for OSHA 30 Success
Topic 1: Hierarchy of Controls
This concept appears everywhere on OSHA 30 exams. The hierarchy (most effective → least effective):
- Elimination — Remove the hazard entirely (best)
- Engineering Controls — Redesign to prevent hazard (guardrails, GFCI, ventilation, etc.)
- Administrative Controls — Policies, procedures, rotation, training
- PPE — Personal protective equipment (least effective; backup only) Key principle: Use the highest-level control possible. Don’t skip to PPE if you can engineer the hazard away. Example question: “A worker is exposed to silica dust from cutting concrete. What’s the best control?”
- A) Require respirators → PPE (least effective)
- B) Wet the concrete before cutting → Engineering (eliminates/reduces dust)
- Correct: B
Topic 2: Root Cause vs. Contributing Factors
OSHA 30 exams emphasize deep investigation, not surface-level blame. Root cause: The fundamental reason the incident occurred (lack of engineering control, policy gap, etc.) Contributing factor: Secondary issues that made it worse (inadequate training, poor communication) Example: A worker falls from scaffolding.
- Surface cause (blame): “He wasn’t paying attention” → Not useful
- Root cause (preventable): “Guardrails were missing from the 10-foot platform” → Actionable
- Contributing factor: Worker wasn’t trained on proper tie-off → Also preventable
Topic 3: OSHA Inspection Procedures
Know the steps of an OSHA inspection:
- Opening conference (manager + worker rep meet inspector)
- Walk-around inspection (inspect site, look for violations)
- Worker interviews (inspector talks to workers)
- Closing conference (inspector presents findings)
- Citations issued (usually 1-2 weeks later) What inspectors look for: All OSHA standards, especially the “Top 10” violations (fall protection, HazCom, ladders, etc.)
Common OSHA 30 Exam Mistakes
Mistake 1: Focusing Too Much on OSHA 10 Topics
OSHA 30 assumes you know hazard recognition. Exams focus on regulations, program development, and problem-solving. Solution: Don’t spend 50% of study time on fall protection basics. You need to know regulations and how to develop safety programs.
Mistake 2: Ignoring the “Why”
OSHA 30 isn’t about memorization. It’s about understanding principles. Example: Don’t just memorize “guardrails must be 42 inches.” Understand why (safe deflection, preventing falls). When asked a scenario question, you’ll apply the principle.
Mistake 3: Not Understanding Hierarchy of Controls
This concept is fundamental to OSHA 30 and appears in many questions. Master it.
Mistake 4: Overlooking New Regulations
Be aware of recent changes (PPE fit requirement Jan 2025, excavation updates, etc.).
Mistake 5: Skipping Weak Topics
If you’re weak on “Incident Investigation” or “Safety Program Development,” that’s where exams will test you most. Force yourself to study these.
OSHA 30 Time Investment
Realistic timeline:
- Fast track (intensive): 1-2 weeks (full-time, 30 hours spread over 4-6 days)
- Standard (balanced): 4-6 weeks (1-2 hours/day)
- Slow track (part-time): 8-12 weeks (30 min/day) Recommended: 4-6 weeks with 1-2 hours daily study. Allows time for review and practice exams.
Ready to Study OSHA 30?
- Confirm you need OSHA 30: Take the free osha.study diagnostic quiz — does your role require it?
- Review the free lead magnet study guide — covers key concepts and top 10 violations
- Enroll in your official OSHA 30 course (360Training, ClickSafety, HSI, etc.)
- Use osha.study practice tests and study bundle for targeted drilling and full-length exams
FAQ
- How much harder is OSHA 30 than OSHA 10?
- Significantly harder. OSHA 30 requires 3x the content (30 vs 10 hours) and moves beyond hazard recognition to regulations, program development, and problem-solving.
- Can I take OSHA 30 if I’ve never taken OSHA 10?
- Yes. OSHA 30 includes all OSHA 10 material, so OSHA 10 is not a prerequisite.
- How long is a typical OSHA 30 exam?
- Usually 75-100 questions, taking 1.5-2 hours depending on your pace.
- What’s a passing score for OSHA 30?
- Generally 80%, same as OSHA 10.
- Is there a limit to OSHA 30 retakes?
- No. Most training providers allow unlimited retakes with access to review materials.