According to DGUV Rule 113-004, "Vessels, silos and confined spaces", confined spaces are defined as areas which are predominantly or completely surrounded by solid walls - which also often incorporates narrow access routes. Such situations may result in a low air exchange rate, which can lead to the accumulation of hazardous substances and impurities. This - coupled with the confined conditions themselves - often gives rise to special hazards that do not occur in other workplaces.
Here are some examples of typical places where work has to be carried out in a confined space:
There are different ways of accessing confined spaces. Particular attention must be paid to fall protection when using the following methods of access:
As opposed to fall danger zones in outdoor areas, falling in a confined space can pose a considerable risk - even if it is only from a low height. On the one hand, heavy soiling might cause someone to slip. On the other, the result of an injury might be significantly more serious due to the fact that rescue options are greatly restricted in such spaces.
As usual, technical fall protection measures should always be given preference over individual protection measures - particularly in confined spaces. Technical solutions, such as firmly-installed working platforms or suspended access equipment, should be used - especially, if your silo or bunker is filled with materials into which you might accidentally sink. In such cases, the use of personal fall protection equipment is generally not suitable.
However, even if personal fall protection equipment is only to be used in the case that a rescue operation needs to be carried out, you should still put this on prior to entering the area - and not take it off. If there are no compelling reasons for not doing so, you should maintain your connection to the rescue equipment at all times. As a preventive measure to protect you when you are working in a confined space with a higher risk level, you might consider using a safety device with an integrated rescue mechanism (e.g. a tripod with a rescue lifting device).