Is a special action necessary when using CO₂ compressed gas cylinders?
Please note two important points:
1) Cylinder: Reusable cylinders are TÜV tested and this is stamped on the cylinder. This test needs to be renewed every 10 years, with the bottom of the cylinder and the valve sealing and threaded joint being tested.
2) The carbon dioxide:
Depending on its concentration, carbon dioxide is harmful in the air.
The respiratory rate and pulse rate increase at a carbon dioxide concentration of 3-5%. Other symptoms are headaches, discomfort and ringing in the ears. Carbon dioxide concentrations of 8-10% and more cause these symptoms to become more pronounced. This may lead to cramps, fainting, apnoea and death from suffocation.
One 500 g cylinder contains 500 g CO2. This is equal to 11.36 mol (chemical substance amount unit). One mol of a gaseous substance has a volume of 22.414 l under normal conditions (273.15 K, 101325 Pa), so that 500 g of CO2 result in a volume of 254.7 l. CO2 is heavier than air, so that it collects on the ground. This corresponds to a CO2 height level in the range of 12.735 mm = 1.27 cm for a room of 20 m². If it is mixed completely with the air in a room of 20 m² and a height of 2.5 m (corresponds to 50,000 l), this corresponds to a maximum gas concentration of 0.5 volume %, which is well below the dangerous level.