hazards in confined space

Hazards in confined space present real dangers. They make confined space works become one of the deadliest works in the workplace.

Recognizing these hazards is the key to confined space safety. Fail to recognize these hazards in confined space will lead to fatal accidents.

Look at the following statistics:

In 2015, according to bls.gov, 136 workers died due to confined space-related accidents.

Meanwhile, in 2010, there were 26 fatalities due to inhalation and 6 fatalities due to oxygen deficiency occurred in confined spaces.

If you can recognize work hazards related with confined space early, then you will be able to take necessary control measures to reduce the hazard level. Even you will have a chance to eliminate these hazards.

But, before doing that, I think it is also important to remind you about what kind of works that are classified as confined space works.

Confined Space Examples

To differentiate confined space and non-confined space works will refer to OSHA definition.

OSHA defines that confined space has limited or restricted means for entry or exit and is not designed for continuous occupancy.

Based on that simple definition, confined space examples include the following works done in:

  • pipelines
  • pressure vessels
  • reactors
  • equipment housings
  • tunnels
  • hopper
  • tanks
  • sewers
  • storage bins
  • elevator fits
  • exhaust ducts
  • and any trench or pits that have a depth equal to or greater than 4 ft.

Confined space works are commonly done during plant turnaround or shutdown maintenance period.

For more examples, you can read my previous post 31 Confined Space Work Examples.

Okay, now we will see the confined space hazards. Just continue reading the following paragraphs.


hazards in confined space

How Many Type of Hazards Are There in Confined Space?

There are 4 hazards associated with working in a confined space:

  • chemical hazards
  • physical hazards
  • electrical hazards
  • fire hazards

Below are the list of confined space hazards, which is associated with the above type of hazards.

Hazards in Confined Space and Control Measures

  1. Lack of oxygen: lack of oxygen can happen when air feed is not enough. Feed more air and exhaust more to avoid this hazard in the confined space. Remember that confined space oxygen level is very critical.
  2. Too much oxygen: this hazard is rare. But, once it appears, fire or explosion will be much easier to happen.
  3. Toxic atmosphere: remaining toxic gas such like H2S or chemical in confined space can create a toxic atmosphere. This will happen only when toxic material normally presents in that space. The key step to avoiding toxic atmosphere is adequate exhaust and clean up.
  4. Hazardous chemical exposure: hazardous chemical exposure such like hydrogen peroxide can happen if lock-out tag-out procedure is not implemented. It can also happen when there is still remaining hazardous chemical left inside. So, make sure you have cleaned-up the remaining chemical. Read the MSDS to know the chemical hazard.
  5. Extreme temperature: it can be very low temperature or very high temperature. Stop any heating or cooling medium that flows into a confined space.
  6. Fire and explosion: remaining flammable gas or liquid in a confined space can be easily ignited as well as cause an explosion to occur. To avoid this, measure the flammable gas or vapor level. If necessary substitute the gas.
  7. Uncontrolled energy: chain reaction is one of the possible causes that may present this hazard. Check this possibility from the MSDS.
  8. A flow of solid or liquid: an unintended flow of solid or liquid can happen if lock-out tag-out procedure is not completely done. Always re-check valve status before starting a confined space work.
  9. Slips: slip and fall hazards can exist if remaining liquid or solid is left. To control such hazards, clean-up is a must.
  10. Falls: fall on the same level and fall to a lower level can happen. Make sure you have removed all the possible causes.
  11. Falling object: work tools that you bring into a confined space can cause falling object hazard. Be sure to attach them tightly.
  12. Struck by an object: piping inside a tank and a ladder are examples of common objects that can injure you. Wear safety helmet.
  13. Electric shock: the use electric power for confined space works is the source of electric short hazard. Make sure you already take adequate measures.
  14. Excessive heat: due to its nature, excessive heat in a confined space will commonly occur, suppose by direct sunshine.
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After you know the confined space hazards, the next step you have to do is to carry out confined space risk assessment.

And do not forget to prepare all the equipment mentioned in the confined space entry equipment list, especially the confined space air quality testing equipment.

Further Reading and Video Training

There are good books to read and video training to watch to improve your knowledge and skills regarding confined space.

Here they are:

confined space hazards and control measures