Work in confined spaces before you start

August 12th, 2011

Confined spaces are places not designed to be occupied by a person and can include vat, tank,  pit, pipe, duct, flue, oven, chimney, silo, container, pressure vessel, underground sewer , wet or dry shaft, trench or  tunnel. Workers who enter these spaces are exposed to increased risks such as

  • Loss of consciousness, injury or death due to poor ventilation and/or hazardous atmospheres
  • Fire or explosion from  flammable contaminates
  • Difficulty rescuing and treating injured or unconscious workers.

Planning how work will be conducted is essential to eliminate confined space risks and prevent injuries or deaths.

Reconsider Design
Designers and manufactures are required to eliminate the need for workers to enter a confined space or, if this is not reasonably practicable, ensure safe means of entry and exit and minimise risks to the health and safety of any person who enters the confined space.

Identify the hazards in the space
Typical hazards in a confined space include

  • Unsafe oxygen levels , too high and too low
  • Fire or explosion this requires an ignition source, air and a fuel 
  •  Engulfment,  usually stored materials such as plastic, sand, grain etc

Other hazards include

  • Uncontrolled introduction of substances eg liquid, gas and solids
  • Biological hazards such as viruses
  • Mechanical hazards such as entanglement, crushing
  • Electrical hazards 
  • Contact with hazardous substances
  • Noise
  • Manual tasks
  • Radiation
  • Environmental hazards (hot, cold or lightning)
  • Outside hazards as work done outside can affect work inside the confined space
  • Any physiological or psychological demands of work

Once the hazards are identified these need to be risk assessed.

Get the right workers the job
Selecting the correct person for the job is essential, as some people may be fearful and far less efficient when working in confined spaces.  This person will need to have competency based training for Enter Confined Space, Work in accordance with an issued Permit.  , and have a trained standby person in case of an emergency.

Prepare the workspace
Be sure to isolate the work area, so everyone else in the vicinity is aware of what’s going on signage may include.  Erect signs to identify the confined space areas indicating  Confined Space Entry Permit requirements.

Test and ventilate the area accordingly, while also ensuring personal protection requirements are available. While monitoring of toxic gases and oxygen levels throughout the work procedure is necessary, initial testing will indicate more likely risks to ensure readiness.
Have rescue equipment available and functional, and clear entry and exit access ways of any obstructions or hazards such as electrical cords.

Plan entry, re-entry and exit
Conditions can change in seconds, so the following points should be considered on re-entry after an extended absence or change in conditions:  Permits must be re-issued, containing the employer’s name, the location of work, and employees assigned. The permit should detail likely hazards to be encountered, which tests are required and any chemical agents to be used. Including rescue arrangements, personal protective equipment used, and any other precautions taken could be useful for future reference.
Testing must be carried out to determine whether any new risks have developed in the confined space, and if the correct ventilation and personal protection requirements are fulfilled.

When the work is done
On exiting the workspace, conduct a review of the operation to reveal any ineffective or incorrect practices. Ensure the entry point is secured, so any hazardous substances cannot escape, and to ensure under-qualified people cannot enter. Clean all equipment of any foreign substances that may have been collected during the work procedures, and which could be transferred to new confined space work environments.
Ticking all the above boxes, continuously monitoring the situation and putting safety first will ensure your workplace remains accident free.