OSHA HAZWOPER 40-Hour exam topics — the 6 content areas by weight
The OSHA HAZWOPER 40-Hour exam is built from 6 weighted content areas. Focus your time where the weight is. Each area below links to a free study chapter and practice questions. Weights reflect the official content outline.
Hazard Recognition & Toxicology
17%exposure routes, IDLH, PEL/TLV, monitoring
PPE Use & Selection
17%EPA Levels A-D, respirators, protective clothing
Safe Work Practices & Engineering Controls
17%buddy system, work zones, confined space
Decontamination & Emergency Response
17%decon lines, ERP, incident command
Medical Surveillance
16%baseline/periodic exams, exposure records
Site Safety & Health Personnel
16%HASP/SSHP, roles, training
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Content-area weights reflect the official OSHA HAZWOPER 40-Hour content outline. Confirm current details with OSHA — 29 CFR 1910.120. Study aid, not a substitute for the official material. Last updated: August 2026.