The Certified Occupational Health Nurse (COHN) credential is awarded by ABOHN — the American Board for Occupational Health Nurses — to registered nurses who specialize in protecting and promoting the health and safety of workers. COHN-certified nurses apply clinical expertise, regulatory knowledge, and health promotion skills within workplace settings across virtually every industry sector.
This free printable PDF covers the full scope of the COHN examination, including occupational health nursing practice standards, OSHA regulations, occupational hazards and their health effects, clinical nursing in the workplace, health promotion and wellness programming, case management and workers compensation, and environmental health. Download it and study offline to build confidence across every domain before your exam date.
The COHN exam tests occupational health nursing across seven major content domains, drawing on both clinical nursing knowledge and the regulatory, industrial hygiene, and case management skills specific to the workplace setting.
You need to know the scope of OHN practice, the OHN role in workplace health programs, and the AAOHN Standards of Occupational Health Nursing Practice. Questions also address evidence-based practice, documentation requirements, and recordkeeping obligations specific to occupational health nursing.
OSHA General Industry Standards are heavily tested. Key standards include Bloodborne Pathogens (29 CFR 1910.1030), Hazard Communication — GHS and Safety Data Sheets (1910.1200), Hearing Conservation (1910.95), Respiratory Protection (1910.134), Personal Protective Equipment (1910.132), and Lockout/Tagout (1910.147). OSHA recordkeeping questions require you to know Forms 300, 300A, and 301, the recordability criteria for work-related injuries and illnesses, and how workers compensation systems handle medical treatment, wage replacement, and return-to-work coordination.
Chemical hazard questions cover routes of exposure (inhalation, skin absorption, ingestion, and injection), threshold limit values (TLVs), permissible exposure limits (PELs), and biological monitoring. Physical hazard topics include noise-induced hearing loss (NIHL), whole-body and hand-arm vibration, ionizing versus non-ionizing radiation, and temperature extremes — particularly distinguishing heat exhaustion from heat stroke. Ergonomic hazard questions focus on musculoskeletal disorders (MSDs), carpal tunnel syndrome, and risk factors including repetition, force, and awkward posture. Biological hazard content covers bloodborne pathogens, respiratory infections, and vector-borne diseases affecting field workers.
Clinical topics include pre-placement examinations, periodic health surveillance programs, fitness-for-duty evaluations, and acute injury and illness management at the worksite. Return-to-work program content covers modified duty, ADA accommodation processes, and coordination with treating physicians. Immunization program management and travel health for international workers are also tested, along with the OHN interface with employee assistance programs (EAPs).
You may be tested on worksite wellness program design, health risk assessment methodology, chronic disease management in working populations, smoking cessation programs, and mental health in the workplace. Questions address stress management approaches, substance use and EAP program interfaces, and how health promotion activities are delivered and evaluated within occupational health settings.
Case management questions cover the occupational injury case management process, coordination among treating physicians, employers, and insurers, and functional capacity evaluations. Work conditioning versus work hardening programs are distinguished. FMLA content includes qualifying conditions and employer obligations. ADA workplace content covers the interactive process, reasonable accommodation analysis, and essential functions determinations.
Industrial hygiene survey methods — air sampling and noise dosimetry — are tested alongside the hierarchy of controls: elimination, substitution, engineering controls, administrative controls, and PPE. HAZWOPER training requirements and emergency response planning are included. Environmental regulation content relevant to OHNs covers EPA CERCLA and RCRA at a conceptual level.
Looking for instant scoring and detailed answer explanations? Our COHN practice test lets you practice interactively, tracks your performance by domain, and highlights the specific topic areas where additional review will have the greatest impact on your score. Pair the online tests with this printable PDF to prepare thoroughly for every section of the ABOHN examination.
| Pros | Cons |
|---|---|
| Validates your knowledge and skills objectively | Study materials can be expensive |
| Increases job market competitiveness | Exam anxiety can affect performance |
| Provides structured learning goals | Requires dedicated preparation time |
| Networking opportunities with other certified professionals | Retake fees apply if you don't pass |
Try these questions from our free COHN Exam practice tests. The correct answer and an explanation follow each question.
An ABOHN-certified nurse is asked to testify as an expert witness in a workers' compensation case. This role falls under which functional domain of occupational health nursing?
Answer: C. Legal and regulatory compliance
Expert witness testimony regarding occupational injury or illness falls within the legal and regulatory compliance domain of occupational health nursing practice.
An ABOHN-certified nurse implements a worksite health promotion program targeting cardiovascular risk. This action reflects which function of occupational health nursing?
Answer: B. Primary prevention through health promotion
Worksite wellness programs targeting risk factors before disease develops represent primary prevention, a core occupational health nursing function.
Which population of workers is the CAOHN (Certified Associate Occupational Health Nurse) credential specifically designed to recognize?
Answer: C. Associate-degree or diploma nurses practicing in occupational health
The CAOHN credential was created to recognize associate-degree and diploma nurses who practice occupational health nursing without a bachelor's degree.
During a facility audit, an occupational health nurse identifies that flammable liquids are stored in standard metal cabinets rather than approved flammable storage cabinets. This represents which category of hazard?
Answer: B. Physical hazard – fire and explosion
Improper storage of flammable liquids creates a fire and explosion physical hazard; OSHA and NFPA standards require approved flammable liquid storage cabinets to contain vapors and withstand fire.