Carbon dioxide (CO2) is a colourless, non-flammable and non-toxic gas. In its free state it is a natural component of air with a concentration of approx. 0.04 vol.% (fresh air 0.03 vol.%, urban air 0.07 vol.%). The maximum workplace concentration (daily average) is 5,000 ml/m3 (ppm) or 9,100 mg/m3. This corresponds to a concentration of 0.5 vol.%. The MAK short-term value for exposure peaks is 1.0 vol.%. Gaseous carbon dioxide is harmless up to 2.5 vol.% in air. Our exhaled breathing air has a concentration of approx. 4 vol.% CO2. High CO2 concentrations cause circulatory weakness, headaches, nausea and vomiting. Even concentrations of 8 to 10 vol.% can have an effect on the heart rhythm and respiratory rate, and can be fatal after 30 to 60 minutes. In its gaseous state, CO2 is heavier than air. For some years it has been clear that carbon dioxide is also a greenhouse gas, as the CO2 concentration rises at the same time as global warming. CO2 emissions are mainly caused by the combustion of fossil fuels. It is also produced in processes for the production of cement, lime or glass. From an environmental point of view, however, CO2 snow blasting is considered to be extremely environmentally friendly, as recycled – already produced – CO2 is reused. For CO2 cleaning, no additional CO2 is generated that influences global climate development. In liquid form it is offered in single gas bottles, bundles or for filling into tanks. Dry ice can be obtained in solid form in blocks, pellets or nuggets. The pre-produced dry ice can only be stored for a limited period because it permanently sublimates and absorbs moisture from the environment.