NEBOSH IDip Exam Pattern (2026 Guide): Units, Assessment Format, Marking & Pass Criteria

The NEBOSH International Diploma requires you to understand its exam structure before you begin your enrollment process. The assessment framework will assess three skills, which include analytical thinking, workplace application and expertise dedicated to strategic safety management.

The National Examination Board in Occupational Safety and Health (NEBOSH) serves as the official certification body, which grants the NEBOSH IDip — a worldwide recognised Level 6 certification.

The NEBOSH International Diploma guide provides complete information about the examination format, assessment methods, grading standards, passing requirements and difficulty levels of the examination.

The qualification consists of three core units:

• DI1 – Workplace Health and Safety Principles

• DI2 – Controlling Workplace Health Issues

• DI3 – Controlling Workplace Safety Issues

These are often referred to as NEBOSH IDip units or NEBOSH Diploma modules.

The NEBOSH IDip is equivalent to UK Level 6, meaning it is academically comparable to a bachelor’s degree standard. It is designed for professionals who want to move into senior HSE roles.

The assessment structure includes one open-book exam and two workplace-based assignments.

• 24-hour open-book exam
• Scenario-based case study questions
• Analytical and application-focused answers required
• Online submission via the NEBOSH portal
• Word count guidance provided

So, is NEBOSH IDip open book? Yes. DI1 is assessed through a 24-hour online open-book examination.

However, “open book” does not mean easy. Candidates must demonstrate:

• Critical thinking

• Application of international standards

• Clear, structured professional writing

• Realistic risk-based solutions

Copying textbook answers can result in a malpractice investigation, as NEBOSH uses plagiarism detection systems.

DI2 focuses on controlling workplace health issues.

Assessment includes:

• Practical risk management application

• Workplace inspection and evaluation

• Evidence-based reporting

• Recommendations aligned with international best practices

This unit requires you to apply learning directly to a real organisation.

DI3 focuses on controlling workplace safety issues.

Assessment involves:

• Hazard identification

• Risk evaluation

• Control measure recommendations

• Structured professional report writing

Both DI2 and DI3 are practical assignments rather than traditional written exams.

An Open Book Examination (OBE) allows candidates to refer to notes and resources. However, NEBOSH evaluates how effectively you:

• Analyse complex workplace scenarios.

• Interpret legislation.

• Apply safety management systems.

• Provide justified recommendations.

The diploma also supports professional growth for obtaining membership to the Institution of Occupational Safety and Health (IOSH) through assessment of professional experience and meeting eligibility criteria.

Grading System

Each unit is graded individually as:

• Pass

• Credit

• Distinction

There is no overall percentage score. You must pass all three units to achieve the diploma.

Each unit has its own minimum pass requirement. Grades are awarded based on performance in that specific unit.

What Happens If You Fail?

• DI1 can be re-sat in a future assessment window

• DI2 and DI3 can be re-submitted

• You can retake the unit that you did not pass

This flexible structure allows learners to progress without restarting the full qualification.

The NEBOSH IDip presents itself as an academically challenging program to students who pursue it.

The program requires students to demonstrate advanced knowledge which exceeds the requirements of the NEBOSH International General Certificate, which exists as a Level 3 qualification.

• 450–550 study hours
• 12–24 months completion timeline

Success requires:

• Strong analytical writing
• Risk management knowledge
• Legislation interpretation skills
• Workplace application ability

• DI1 exams are conducted during fixed assessment windows.

• DI2 and DI3 have specific submission deadlines.

• Registration is completed through NEBOSH-accredited training providers.

• Results are typically released several weeks after submission.

Candidates should confirm exam windows and registration timelines with their chosen provider.

To improve your chances of success:

1. Understand NEBOSH command words such as analyse, evaluate, and justify.

2. Structure answers using recognised risk management frameworks.

3. Practice scenario-based analytical writing.

4. Plan time carefully during the 24-hour OBE.

5. Use real workplace evidence in DI2 and DI3.

6. Avoid generic or copied responses.

The assessment structure, which you need to evaluate early in your career assessment, will help you achieve your goal of obtaining HSE Manager, Regional Safety Lead, or Corporate Risk positions.

Understanding the NEBOSH IDip exam pattern is the first step toward success. The qualification exists to assess knowledge while developing safety leaders who can efficiently handle strategic risk management.

If you wish to gain recognition and professional credibility in senior HSE positions, choose our most respected occupational health and safety qualification – NEBOSH IDip.