43
11.
S
AFETY
11.1
L
IQUID
CO
2
BACKUP
1)
Precautions for the use of CO
2
Properties of CO
2:
-
Does not sustain life or combustion.
-
Present in low concentrations (0.03%) in air.
-
Makes the atmosphere unbreathable at concentrations exceeding 3%.
-
Accelerates respiratory rate, induces faintness, vomiting, coma or
even death.
-
Heavier than air (d=1.53).
-
Non-flammable, colourless gas with a slightly acidic odour at high concentrations.
-
When liquid CO
2
is released at atmospheric pressure, carbon dioxide snow is generated at a temperature of –
80°C.
Ensuing risks:
-
Risk of asphyxiation. Loss of consciousness occurs when concentration exceeds 8 to 10%.
-
CO
2
builds up in low areas.
-
Risk of frostbite.
-
Risk of corrosion of steels in the presence of humidity.
Critical precautions to be taken:
-
Areas where CO
2
is stored or used must be well ventilated (extraction or ventilation at both high and low levels
in the room).
-
Areas liable to contain an unbreathable atmosphere must be indicated with a
CO
2
– risk of asphyxiation
hazard
pictogram.
-
Never enter a room that has contained CO
2
without taking predefined precautionary measures.
-
Eliminate links between areas where CO
2
is stored or used and low points (pits, drainage channels, basements)
where it could accumulate and render the atmosphere unbreathable.
-
Use a CO
2
concentration detector (or O
2
concentration detector) to check that the CO
2
concentration is less
than 0.5% (as recommended by INRS, French National Research and Safety Institute).
In case of incident or accident:
-
If asphyxiation has occurred
-
Check the oxygen concentration in the room and then take the victim to the open air (taking an insufflator
with you).
-
Begin artificial respiration and call the emergency services.
-
In the event of a leak
-
Do not enter the room without breathing apparatus if the carbon dioxide concentration is higher than
3%.
-
Close the valve on the cylinder.
-
Aerate the room at length, ensuring that low points are ventilated.
