In terms of gas properties, carbon dioxide gas is non-toxic, but too high concentration in the air will cause suffocation. The reason is that the concentration of carbonic acid in the blood increases, the acidity increases, and acidosis occurs.
The normal content of carbon dioxide is 0.04%. When the concentration of carbon dioxide reaches 1%, people will feel stuffy, dizzy and palpitation. When it reaches 4% - 5%, people will feel asthma, headache and dizziness. When it reaches 10%, people and animals can die in a short time.
Carbon dioxide is a kind of carbon oxygen compound, which is a common compound in the air. It is colorless, tasteless, non combustion supporting and non combustible under normal pressure. Slightly soluble in water to form carbonic acid, which is a weak acid.
Carbon dioxide can generally be prepared by calcining limestone at high temperature or reacting limestone with dilute hydrochloric acid. It is mainly used to refrigerate perishable food (solid), as refrigerant (liquid), manufacture carbonated soft drinks (gaseous) and solvents for homogeneous reaction (supercritical state), etc.
Carbon dioxide is suitable to be stored in a cool and ventilated special warehouse for non combustible gas, and is suitable to be transported in liquid or solid form. The following points shall be paid attention to when storing and transporting carbon dioxide:
1. Keep away from kindling and heat source, and the storage temperature should not exceed 30 ℃.
2. Store them separately from inflammable (combustible) materials, and do not mix them.
3. The storage area shall be equipped with leakage emergency treatment equipment.