Hospital OR and ICU: Special Fire Protection

When a hospital fire breaks out, evacuating patients is often not an option, so hospitals follow a defend-in-place approach. The operating room (OR) and the ICU are the two most sensitive areas: patients cannot be moved at a moment’s notice and life support must keep running. NFPA 99 Health Care Facilities Code and NFPA 101 address these areas specifically. The combination of ignition sources, an oxygen-enriched atmosphere and medical gases is what makes an OR fire unique.

OR Fire Triangle

On site the three legs of the OR fire triangle are summarized as follows:

• Fuel: Alcohol-based skin antiseptics, surgical drapes, dry gauze
• Oxidizer: Near-100% O₂ atmosphere around the patient’s mask
• Ignition source: Electrosurgical units (monopolar cautery), lasers, fiber-optic light sources

When these three come together, some 200–240 OR fires a year are reported in the US (FDA and ECRI data).

Medical Gas Shutoff

OR gas lines must shut off immediately in an emergency:

• Zone valve box: Outside each OR, in a clearly visible and easily accessible location
• Gases that can be shut off: O₂, N₂O, medical air, vacuum
• Labeling: Every valve color-coded; emergency contact details on the panel
• Testing: NFPA 99 requires a full functional test once a year

Sprinklers and Alternatives

Water-based sprinklers in the OR are always debated on site because of concerns about contaminating the sterile field and damaging sensitive equipment. The options compared on projects:

• Wet-pipe sprinklers: Recommended by NFPA 13 and NFPA 101; the risk of water damage is accepted
• Preaction sprinklers: Cross-zoned detection reduces false discharges to almost zero
• Clean agent (FM-200 or Novec 1230): Suitable for electronics rooms; rarely chosen for ORs
• Water mist: Up to 80% less water; suppression without drenching the sterile field
• Portable extinguishers: CO₂ or water-mist type, within the team’s reach

Smoke Compartments

NFPA 101 Ch. 18/19 smoke compartment rules:

• Each smoke compartment ≤2,100 m2 (22,500 sq ft); ≤3,720 m2 (40,000 sq ft) in hospital compartments where all patient sleeping rooms are single-patient or that contain no patient sleeping rooms (NFPA 101-2024 18.3.7.1; existing facilities 19.3.7.1, subject to sprinklers)
• Smoke barriers per NFPA 101-2024 Section 8.5, with at least 1-hour fire resistance in new facilities (18.3.7.3) and at least 1/2-hour in existing facilities (19.3.7.3)
• Every patient area must have access to at least 2 separate smoke compartments
• At least 2.8 net m2 (30 net sq ft) of accumulation space per patient on each side of the smoke barrier (NFPA 101-2024 18.3.7.5.1); in new facilities every story used by inpatients for sleeping or treatment is divided into at least two smoke compartments (18.3.7.1), in existing facilities this applies to stories with sleeping rooms for more than 30 patients (19.3.7.1)
• Corridors at least 2.4 m wide (for horizontal evacuation)

Operational Readiness

1. RACE protocol: Rescue, Alarm, Confine, Extinguish — all OR staff must be trained
2. PASS: Pull, Aim, Squeeze, Sweep — portable extinguisher use
3. Fire drills: Every three months for each OR and ICU team
4. Evacuation or defend in place: In health care occupancies under NFPA 101 Chapters 18/19, defend-in-place is the basic approach; where needed, patients are moved horizontally (partial evacuation) into an adjoining smoke compartment
5. Fire door testing: Annual self-closing test under NFPA 80

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