Fires in oxygen enriched atmosphere start easily and are very intense, so the people injured suffer very serious burns, which are often fatal or cause very severe and prolonged suffering. Usage of Oxygen in hospitals are very common, During the pandemic COVID 19, the consumption of oxygen became very high, with a maximum consumption of 55 liters of oxygen gas for medical equipment Such as high flow nasal cannula and Ventilators at general ward and ICU. WHO estimates that at the current rate of ~ 1 million new cases a week, the world needs about 620,000 cubic meters of oxygen a day, which is nearly 88,000 large cylinders.
The Physical Properties of Oxygen
Oxygen Colorless & odorless gas Oxygen changes from a gas to a liquid at a temperature of -182.96°C (-297.33°F) when it takes on a slightly bluish color, Liquid oxygen can then be solidified or frozen at a temperature of -218.4°C, Oxygen does not burn, but readily supports combustion of other substances. It is capable of reacting with most metals and organic materials. The rate of reaction varies with the material and other conditions. The reaction may be slow (as in the rusting of steel) or rapid (as in combustion and explosion).
Oxygen enrichment is a generic name for the hazards associated with gases and liquids containing oxygen concentrations greater than 21%. Gases containing more than 21% oxygen are termed oxygen enriched gases. A breathing atmosphere containing more than 21% oxygen is termed an oxygen enriched atmosphere. A liquid with greater than 21% oxygen is termed oxygen enriched liquid (for example, RL (rich liquid) is usually 35-40% oxygen)
Combustion in an Oxygen-Nitrogen Oxygen-Enriched
Complete Combustion: The filter paper strip burns completely. Incomplete Combustion: The filter paper strip burns for a length greater than 1 cm (2.54 in.) from a resistance wire igniter, but the flame extinguishes itself before the strip is completely consumed. Slight Combustion: The filter paper strip flames or smolders, but does not burn more than 1 cm (2.54 in.) from the resistance wire igniter. Non combustion: No ignition.
Causes of Oxygen Enrichment
- Oxygen enrichment of the atmosphere can be the result of:
- Leaking medical gas pipeline in the hospitals.
- Liquid oxygen spill (Liquefaction) during refiling of liquid oxygen tanks.
- Waste of oxygen during treatment the patients in ICU.
- Waste of oxygen during Surgeries called (surgical fire- Airway surgical fire).
- Leaking of oxygen gas cylinders during transporting of cylinder.
Sources of Ignition
- Naked or open flames such as lighted cigarettes.
- Static discharge.
- AC spark plugs.
- An electrical spark or fault causing overheating.
- Heat sources (tea boiler…..)
- In 12 May 2020 Fire was in Russian hospital kills 5 coronavirus patients, ventilator could be to blame.
- In 13 June 2020 Fire was in Egypt, Tanta hospital in ICU have been evacuated patient in ICU.
- In 28 June 2020 Fire was in Egypt, Badrawi hospital kills 7 coronavirus patients in ICU.
- ECRI has announced in 2005 the risk of fire was reported during treatment the patient with oxygen.
Fire-Stopping Techniques/ Oxygen Enrichment Precautions and Safeguards
- Separation of combustible materials from oxygen enriched gas or liquid.
- Separation of flammable materials from oxygen enriched gas or liquid.
- A clear procedure for safety and security during refile liquid oxygen or cylinders.
- Indoor air quality is very important to decreasing of the percentage of oxygen
- Flash over barriers.
- Fire drills and training are very important with medical protocol to evacuate ICU or OR patients.
NFPA 99, NFPA 53 ,NFPA 55