The ABOHN COHN-S (Certified Occupational Health Nurse-Specialist) exam validates advanced occupational health nursing expertise at the specialist level.

Exam Format

• •Total Questions: 160 (135 scored + 25 pretest)
• •Time Limit: 3 hours
• •Eligibility: Bachelor’s degree + RN + 3,000 hours OHN experience

What Makes the COHN-S Challenging?

1. Management and Leadership Content

The COHN-S has 22% management content compared to 10% for the COHN. This includes program design, budgeting, quality metrics, and strategic planning — topics that require business acumen beyond clinical nursing.

2. Regulatory Complexity

The exam tests OSHA medical surveillance requirements, EPA regulations, ADA accommodations, FMLA, and workers’ compensation law. Navigating this regulatory landscape requires dedicated study.

3. Industrial Hygiene Knowledge

Understanding chemical exposure limits, noise dosimetry, ventilation engineering controls, and hazard assessment requires technical knowledge beyond nursing school curricula.

4. Dual Clinical-Management Focus

The COHN-S requires both clinical expertise (45% of exam) and management expertise (22%). Candidates strong in one area may struggle in the other.

Frequently Asked Questions

Is the COHN-S harder than the COHN?

The exams have the same format and time limit. The COHN-S has more management content, which some candidates find more challenging. ABOHN recommends choosing based on your role, not perceived difficulty.

What is the pass rate for the COHN-S?

ABOHN does not publish pass rates. Experienced OHNs with dedicated preparation generally report successful outcomes.

Can I take the COHN-S without a BSN?

Yes. ABOHN accepts a bachelor’s degree in any field — it doesn’t have to be nursing. You need a bachelor’s degree (any discipline) plus an active RN license.