Istanbul Basaksehir, Ankara Bilkent and Mersin City Hospitals are thousands-of-beds mega-complexes that use EO (ethylene oxide) to sterilize surgical kit. 100 percent EO is explosive with LEL 2.6 percent. NFPA 55 requires 30+ ACH, Class I Div 2 wiring and deluge sprinkler in EO rooms.
Ethylene Oxide
- Flash point: -18 C Class IA
- LEL-UEL: 2.6-100 percent (self)
- Autoignition: 429 C
- Molar mass: 44 g/mol
- TLV: 1 ppm TWA
NFPA 55 Classification
- Sterile room: Class I Div 2
- Cylinder area: Div 1
- Ventilation: 30 ACH
- Emergency vent: 100 ACH leak
- Detector: IR 1 ppm
Sterile Cycle
- Temperature: 37-63 C
- RH: 40-80 percent
- Concentration: 450-1,200 mg/L
- Duration: 1-6 h
- Post aeration: 12-24 h
Fire Protection
- Deluge sprinkler: 12.2 L/min/m2
- Sterilizer: CO2 no water
- Abatement: Catalytic oxidation
- Scrubber: Water wash
- Nitrogen purge: Cylinder transfer
Historic Events
- Sterigenics Willowbrook 2019: EPA shutdown
- BD Columbus 2020: EO emission
- Istanbul Basaksehir CH: 2,680 beds
- Ankara Bilkent CH: 3,711 beds
- FDA guidance: EO alternative H2O2
EO with SprinkCalc
SprinkCalc sizes EO sterilization deluge 12.2 L/min/m2, 30 ACH ventilation, IR detector 1 ppm and NFPA 55 Class I Div 2.
Download SprinkCalc on the App Store
Sources & Further Reading
NFPA 55, NFPA 99, ANSI AAMI ST41, EPA NESHAP, FDA 510(k). NFPA 55 Compressed Gases and Cryogenic Fluids.