How Can we Identify a Confined Space?
A confined space is a space that has any one of the following characteristics:
- ♦ Limited openings for entry and exit
- ♦ Unfavorable natural ventilation
- ♦ Not designed for continuous worker occupancy
Whenever we are required to carry out a Survey in a:
- Boiler, pressure vessel,
- Cargo, ballast, fuel oil, or lube oil tank,
- Cargo hold, void space, pumproom, or similar type enclosure,
Then we would be working in a confined space.
Limited openings for entry and exit:
Confined space openings are limited primarily by size or location. Openings are usually small in size, perhaps as small as 450 mm (18 inches) in diameter, and are difficult to move through easily. Small openings may make it very difficult to get needed equipment in or out of the spaces, especially life-saving equipment when rescue is needed.
However, in some cases openings may be very large, for example opentopped spaces such as ships’ holds. Access to open-topped spaces may require the use of ladders, hoists, or other devices, and escape from such areas may be very difficult in emergency situations.
Unfavorable natural ventilation:
Because air may not move in and out of confined spaces freely due to the design, the atmosphere inside a confined space can be very different from the atmosphere outside.
Deadly gases may be trapped inside, particularly if the space is used to store or process chemicals or organic substances which may decompose.
There may not be enough oxygen inside the confined space to support life, or the air could be so oxygen-rich that it is likely to increase the chance of fire or explosion if a source of ignition is present.
Not designed for continuous worker occupancy:
Most confined spaces are not designed for workers to enter and work in them on a routine basis. They are designed to store a product, enclose materials and processes, or transport products or substances. Therefore, occasional worker entry for Survey, inspection, maintenance, repair, cleanup, or similar tasks is often difficult and dangerous due to chemical or physical hazards within the space.
A confined space found in the workplace may have a combination of these three characteristics, which can complicate working in and around these spaces as well as rescue operations during emergencies. If a Survey requires you to enter one or more work spaces with the characteristics listed above.
Points to pounder are ;
The atmosphere in a confined space may be extremely hazardous because of the lack of natural air movement. This characteristic of confined spaces can result in
- Oxygen-deficient atmospheres,
- Flammable atmospheres, and/or
- Toxic atmospheres.