Confined space work in Germany: hazards, entry permit and rescue

What are confined spaces and tanks?

Confined spaces and tanks are areas enclosed entirely or mostly by solid walls in which, because of the restricted space, poor air exchange or the substances and equipment inside, the hazards are significantly higher than at normal workplaces. That is the definition in DGUV Rule 113-004 “Tanks, silos and confined spaces – Part 1: Work in tanks, silos and confined spaces” (Behälter, Silos und enge Räume). What matters is not size alone but the particular hazard: a broom cupboard in normal use is not a confined space, whereas a weighbridge pit in which gases can collect is.

• Containers, tanks, reactors and vessels
• Silos and bunkers for bulk materials
• Shafts, ducts, pits, tank bunds and weighbridge pits
• Cavities in buildings and machines, box girders of bridges and cranes
• Hubs, rotor blades and spinners of wind turbines

Any presence in the space counts as work – walking in, climbing in, descending, and even leaning in through a manhole. Typical reasons are cleaning, inspection, servicing, repair and troubleshooting.

Typical hazards in confined spaces

• Oxygen deficiency

  Typical causesInert gases such as nitrogen from purging, fermentation and decay, substances or tank walls that bind oxygen, inadequate ventilation

• Toxic gases and vapours

  Typical causesResidues, stirred-up sludge, cleaning agents, welding fumes, substances from leaking pipes or isolations

• Fire and explosion

  Typical causesFlammable vapours, combustible dust that has been stirred up, oxygen enrichment, for example from leaking welding equipment

• Engulfment, burial, drowning

  Typical causesBulk material forming bridges or cavities, material flowing in, liquids

• Mechanical and electrical hazards

  Typical causesAgitators, screw conveyors, valves that open, falling parts; conductive surroundings with little freedom of movement

• Other strains

  Typical causesHeat or cold, falls, physical exertion, psychological strain from confinement, height and limited visibility

Which rules apply in Germany?

There is no specific law on confined spaces. The duties arise from several regulations that DGUV Rule 113-004 brings together for practical use. As a DGUV rule it does not carry a legal presumption of conformity, but it is regarded as a suitable guide for meeting the duties.

• Sections 5 and 10 of the Occupational Safety and Health Act (ArbSchG)

  What it requiresRisk assessment before the work; organise first aid, recovery and links to emergency services

• Section 8 of DGUV Regulation 1

  What it requiresSupervision by a reliable person familiar with the work when dangerous work is done jointly; additional personal protection when someone works alone

• Section 25(3) of DGUV Regulation 1

  What it requiresProvide rescue equipment and means of rescue transport

• Hazardous Substances Ordinance (GefStoffV) Section 9(7) and Annex I no. 1.4

  What it requiresSupervision or additional measures for lone working with hazardous substances; permit-to-work system with written instructions where there is a fire or explosion hazard

• Sections 10(3) and 11(2) of the Ordinance on Industrial Safety and Health (BetrSichV)

  What it requiresPermit systems for maintenance; rescue and anchorages for rescue equipment on work equipment

For wastewater facilities, DGUV Rules 103-003 and 103-004 also apply, and for handling transportable silos, DGUV Rule 113-005.

Entry permit, supervisor and standby person

Before work starts, the responsible person – the employer or an appointed person – issues an entry permit that sets out all protective measures. The supervisor, the standby person and, where applicable, a contractor's responsible person confirm with their signature that they know the measures. A carefully completed permit is at the same time the risk assessment for this job at this point in time. After longer interruptions, for example the next day, or when the persons involved change, it is reissued or extended. Where conditions are always the same and the same effective measures apply, written operating instructions (Betriebsanweisung) can replace the permit.

• Supervisor: reliable, familiar with the work and authorised to give instructions; checks before the start and at appropriate intervals that the measures are being followed, and must be available at short notice
• Standby person: keeps constant contact with the people inside – usually by line of sight, otherwise via voice link, signal line or lone worker alarm – can summon help at any time and knows the rescue measures
• Person carrying out gas testing: has expertise in measuring devices, substances and the installation, for example under DGUV Principle 313-002

Protective measures before and during the work

Because of the high hazard potential, the first question is always whether entry can be avoided – for example with cleaning devices operated from outside or an inspection by camera. If someone has to go in, this sequence applies:

1. 1

   Empty and clean

   Remove the contents without entry wherever possible, flush or steam out residues. Take into account fire and health hazards from cleaning agents.

2. 2

   Isolate

   Effectively disconnect all pipes through which substances, gases, heat or pressure could enter – for example remove spool pieces and fit blank flanges, insert spectacle blinds, or close two valves with a bleed in between and secure them against opening.

3. 3

   Isolate energy

   Disconnect all drives from every energy source and secure them against being switched back on; lockout-tagout systems have proven effective. Release stored energy, shut down filling and discharge equipment.

4. 4

   Ventilate

   Ventilate with fresh air so that the whole space is flushed through – never with oxygen. Monitor the ventilation; if it fails, work must stop immediately.

5. 5

   Gas test and monitor

   Measure competently at a representative point and document the results. During the work, a gas detector often monitors the atmosphere; for this, instructing the standby person is sufficient.

6. 6

   Define protective equipment and work equipment

   Respiratory protection if dangerous concentrations are still possible; hand lamps only on safety extra-low voltage; no compressed gas cylinders inside the tank except for breathing apparatus and fire extinguishers.

• Oxygen

  Reference value under DGUV Rule 113-004Natural air contains 20.9 vol%; if readings differ, find the cause. Filter devices only if no hazard from oxygen deficiency can occur; below 17 vol% only with self-contained breathing apparatus

• Flammable gases, vapours, dusts

  Reference value under DGUV Rule 113-004An explosive atmosphere is considered prevented if the concentration stays permanently below 50% of the lower explosive limit

• Toxic substances

  Reference value under DGUV Rule 113-004Occupational exposure limits and other assessment benchmarks; set specific release and alarm thresholds in the risk assessment

Plan and practise the rescue

The employer whose staff work in the space is responsible for rescue. If several companies are involved, they agree on who carries out the rescue and record it, for example on the entry permit. Because minutes usually count, the equipment generally belongs at the entry point; keeping it centrally with the works fire brigade only makes sense if hazardous substances and oxygen deficiency are ruled out.

• Wear the rescue harness during the work and keep it connected to the rescue device wherever possible
• Provide anchor points for rescue lifting devices above the access opening and keep the opening clear
• Only descend on a fall arrest harness if the lift back up takes no more than five minutes
• Prepare a written rescue plan for complex situations and include external rescue services in drills
• If there is a fire risk, keep foam or water extinguishers ready – CO₂ and powder are generally unsuitable in confined spaces

Checklist: work in confined spaces

• Checked whether the work can be done without entry
• Risk assessment carried out for this job
• Supervisor and standby person appointed
• Entry permit issued and signed by everyone involved
• Tank emptied, cleaned and isolated from all pipes
• Drives and energy sources isolated and secured against switching on
• Ventilation set up, gas test done, continuous monitoring arranged
• Rescue equipment on site, rescue practised, emergency call arranged
• Everyone involved instructed, at least annually for recurring work

Free templates for this guide

As PDF and Excel, free – to use in your own company.

• Work permits

  Confined space entry permit template (PDF) for tanks, silos and shafts

  PDFFree download

Frequently asked questions