To prevent fires a good knowledge of why they start is important Fire Prevention
Fuel The Fire Triangle FIRE A FIRE REQUIRES OOOPS Oxygen FIRE IGNITION PLUS A FOOL TO PUT THEM TOGETHER
Electrical, electrostatic or break arc Hot surface, friction spark or heated wire Heated gases independent of surfaces, generated by adiabatic compression or jets of hot gas Exothermic chemical reaction Mechanical source of friction heating and particle impact Laser sources Ignition may be from
Matches Lit cigarettes Cigarette lighters, pocket warmers Electrical items, radios, torches, batteries, Hand Phone. MP3 Players Heat packs, or chemicals Friction toys, welders spark gun Lighting Ignition sources in chambers
This process begins at any increase over 21 % oxygen by volume at 1 ATA Burn rate starts to accelerate considerably after 23.5% oxygen by volume. Therefore at no time will any chamber oxygen level be over 23.5 % If this is not known, consideration should be given to aborting the treatment Speed of burn increases as oxygen level and or pressure increases
When pressure and or oxygen levels increase burns rates also increase (Cook Diagram). These changes also effect ignition temperature, which decreases, significantly Therefore the friendly HBOT system atmosphere is unfortunately well suited to easier ignition and faster burning of fire The effect of oxygen and pressure on burn rates
Is determined by available oxygen and fuel Control of fuel and oxygen is fundamental in fire management Low oxygen, low fuel, slow / low spread of flame Flame propagation
Mattress Pillows Sheets Clothing, NO POCKETS Paper, books magazines Newspapers? If hot enough and O2 then almost anything will burn Fuel sources in chambers
Cotton sheeting NFPA Ch 19 table 220.127.116.11 Minimum hot plate ignition This shows that increasing oxygen levels combined with raised pressure, lowers the ignition temperature
All occupied chambers must have some pockets of differing gas, Heterogeneous (not well mixed) Therefore it is possible that the measured oxygen concentration may be high in pockets Sheffield showed that this may be minimal PP Curve disperses gas quickly, but possibly not quite evenly New evidence suggests that oxygen may collect near or under the floor plates Is chamber gas homogenous?
We should only have “A” Class material in a chamber If careful control of all material in a chamber is taken (NO POCKETS) Use fire retardant products (seating materials etc) “A” Class material is effectively controlled by using water Also Fires need time to become established Are Hyperbaric Fires Controllable?
This must be possible No electricity No matches, lighters (NO POCKETS) Nothing should be taken in. Only have what is allowed in the chamber. Exclude ignition!!
If a fire starts water must be available • Regular system tests, tx pre tests, and bi annual full tests, must be fastidiously carried out, and the results carefully logged • No deaths have occurred, in any chamber when water is quickly available, and the oxygen level is less than 23.5% • this is a very achievable goal, and it NEEDS TO BE COMPLIED WITH !! Fire prevention is best
Water is best medium to fight hyperbaric Fires It must be available quickly Water storage. Water pressure controls delivery Fire System
NFPA Independent Air Source Deluge and Hand Held Hoses Minimum Flow for 60 seconds (one minute) How often do you test? Do you record the results? Fire Systems
All occupants on BIBS, protect your own airway FIRST • Immediately deluge with water. • Inform all of the “Team” • Start an emergency ascent These actions should be almost simultaneous • Prepare to assist occupants on surfacing • Fire may re-ignite on door opening Actions in a fire
All events that may occur in a hyperbaric chamber should be considered and planned for. “Normal” procedures and those that deviate from “Normal” are should be covered in the Units Standard Operational Procedures Manual All procedures need to be practiced - regularly These should include the emergency ones Emergency Procedures
Technical Emergencies Medical Emergencies Fire Emergencies General Emergencies HBO Personnel shall be knowledgeable in and have a written procedure for:
Technical Emergencies • Loss of pressurizing gas air • Loss of primary oxygen • Rapid Increase in chamber pressure • Rapid decrease in chamber pressure • Loss of back up pressurizing gas • Loss of back up oxygen source • Contaminated breathing gas either source or chamber environment • Loss of communications • Loss of power
Medical Emergencies • Management of Seizures CNS Oxygen toxicity • Cardiac arrest, including defibrillation • Barotraumas during descent/ ascent • Claustrophobia and acute anxiety • Suspected pneumothorax • Aggressive or violent patient
Fire and General Emergencies FIRE • Fire inside the HTS (Chamber) • Fire in the room, adjacent area • Accidental fire deluge activation GENERAL • Omitted decompression. • Incapacitation of the technician • Illness of the attendant • Emergency entry of the outside assistant • Requesting help in the chamber area • Emergency decompression.
Prohibited Items /Contraband!! • Sources of Ignition:Matches, Lit cigarettes, Cigarette lighters, pocket warmers, Electrical items, radios, torches, batteries, Heat packs, or chemicals, Friction toys, welders spark gun, Unsuitable clothing (Synthetics and pockets) • Sources of contamination: Oil, Smell, HP Cylinders, Other Gases, Mercury (Thermometers, BP Devices), some ointments.
Sources of additional fuel: Newspapers, Extra Magazines, Bedding, Unsuitable clothing (Synthetics and having pockets), oily materials, Bandages and ointments. • Documentation and Procedures ONLY TAKE IN ESSENTIAL APPROVED MATERIALS, NOTHING ELSE !!!
We should only have “A” Class material in a chamber If careful control of all material in a chamber is taken (NO POCKETS) “A” Class material is effectively controlled by using water Also Fires need time to become established Are Hyperbaric Fires Controllable?
Fire hazard from high oxygen concentrations Potential explosion of badly handled cylinders Depletion of oxygen supply Potential Problems
The compressed energy of a HP gas cylinder is enormous It will kill, destroy buildings if allowed to Always firmly fix cylinders when stored large ones upright, small ones on side Always use a cart for larger cylinders (fix to cart) Never leave standing up unless it is firmly fixed SNIFT before connecting Always turn on slowly, only use correct pressure rated equipment HP Cylinders
The atmosphere By fractional distillation Produces very pure gas Decanted, compressed further into HP cylinders Assures quality Absorption swing system, less pure oxygen Where does oxygen come from?
Draws in air Removes CO2, dust, Oil Compressed, cooled to turn gas, air into a liquid. (-196 deg K at ~ 600kPa) Distilled stored Compressed evaporated into cylinders HP pure gas ready for use Fractional distillation process
Oxygen here is Green (Same as USA), Germany it is blue, UK/ Australia Black with white top Be sure of your gas Analyze is best to be sure be careful when traveling All gasses have colour codes
HP Gas storage cylinders Oxygen manufacture Oxygen hazard Calculating gas supply duration/ needs Hyperbaric oxygen environment (fire risk) Safe Gas Handling
Oxygen supports combustion High oxygen concentrations accelerates burn rate Always ventilate the area Never have exposed flame etc, no smoking where oxygen is being used Oxygen is odorless colorless. It can be present in large dangerous quantities, without being aware of it Oxygen Fire Hazard
Existing Chamber Facilities Singapore General Hospital • Hyperarichealth.com