CHS Study Guide 2026
Everything you need to pass the CHS exam in one place: the exam format, every topic to study, real practice questions with explanations, flashcards, and full-length practice tests. Free, no sign-up needed.
📋 CHS Exam Format at a Glance
📚 CHS Topics to Study (37)
✍️ Sample CHS Questions & Answers
1. When inspecting a hyperbaric chamber viewport (acrylic window), which finding requires the chamber to be taken out of service immediately?
Crazing or deep scratches in acrylic viewports indicate structural compromise; such viewports can fail catastrophically under pressure and must be replaced before use.
2. Which formula correctly expresses absolute pressure (ATA) for a diver at depth D in feet of seawater?
Absolute pressure in ATA equals 1 (surface atmospheric pressure) plus the gauge pressure, where each 33 feet of seawater adds 1 ATA.
3. In CHS practice, what constitutes a conflict of interest?
A conflict of interest occurs when personal, financial, or other interests could potentially influence professional judgment and decisions.
4. In hyperbaric facilities, the primary reason for prohibiting wool and synthetic fabrics inside the chamber is:
Synthetic and wool fabrics can generate electrostatic discharge, which is a significant ignition risk in hyperbaric oxygen environments.
5. A hyperbaric chamber operator discovers a patient is experiencing arterial gas embolism (AGE) immediately after surfacing from a dive. The treatment protocol of choice is:
USN Table 6 at 2.8 ATA with oxygen periods is the standard recompression treatment for AGE and severe decompression sickness.
6. The documentation required by CMS for hyperbaric oxygen therapy includes all of the following EXCEPT:
CMS does not require a liability waiver; it requires physician evaluation, per-session notes, and documentation of an approved indication for reimbursement.