The Certified Occupational Health Nurse (COHN) and Certified Occupational Health Nurse–Specialist (COHN-S) credentials are awarded by the American Board for Occupational Health Nurses (ABOHN). COHN requires an active RN license, 3,000 hours of occupational health nursing experience within the past 5 years, and passing an examination covering clinical practice, case management, workplace hazards, regulatory compliance, and program management. COHN-S has higher requirements: a bachelor's degree or higher, 5,000 hours of OHN experience, and an advanced examination. Both certifications are renewed every 5 years through continuing education units (CEUs) or re-examination. These credentials signal expertise in workplace health program administration, injury/illness management, and regulatory compliance.