Confined Spaces are Dangerous Places

Sewers are often confined work spacesWHAT IS A CONFINED SPACE?

A confined space can be any space of an enclosed nature where there is a risk of death or serious injury from hazardous substances or dangerous conditions (eg. lack of oxygen).

Some confined spaces are fairly easy to identify, eg enclosures with limited openings:

  • Storage tanks
  • Silos
  • Enclosed drains
  • Sewers
  • Manholes
  • Vaults

Others may be less obvious, but can be equally dangerous, for example:

  • Open-topped chambers
  • Storm box culverts
  • Trenches & pits
  • Ductwork
  • Crawl spaces
  • Unventilated or poorly ventilated rooms
  • Engine compartments
  • Dump truck beds & vehicle undercarriage

It is not possible to provide a comprehensive list of confined spaces. Some places may become confined spaces when work is carried out, or during their construction, fabrication or subsequent modification. NEVER enter a Confined Space without the correct training, supervision, risk assessments and written method of work.

Lack of oxygen and toxic fumes are highly dangerous aspects of working in confined spacesWHAT ARE THE RISKS?

A number of people are killed or seriously injured in confined spaces each year in the U.S. This happens in a wide range of industries, from those involving complex plant to simple storage vessels. Those killed include not only people working in the confined space but those who try to rescue them without proper training and equipment.

Dangers can arise in confined spaces because of, lack of oxygen, poisonous gas, fume or vapors, liquids/solids that can fill the space, fire, explosion and hot conditions.


A suitable and sufficient assessment must be carried out of the risks for all work activities for the purpose of deciding what measures are necessary for safety. For work in confined spaces, this means identifying the hazards present, assessing the risks and determining what precautions to take. A confined space risk assessment must be carried out by a company designated competent person with sufficient experience and familiarity with the relevant work and equipment so that they fully understand the risks involved.


Utilize the FSI Safe Work Permit and carry out atmospheric testing. Determine if the space is permit required or is a non-permit required space. Many are non-permit requiring but are still potentially dangerous. Have a light source, a rescue plan and utilize the tripod with a harness for entry so the attendant does not have to enter to rescue the entrant. Ventilation and fresh air are needed to ensure safe breathing atmosphere for the entrant. Discuss the hazards and the controls at the Daily Huddle toolbox before starting the work. Plan ahead several days to assemble all the required tools and training before they are needed.

Confined spaces are dangerous places; review the hazards and establish controls before entering one.

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