Safety in Confined Spaces

Many, or perhaps even most, workplaces have something on the premises that would be correctly termed a "confined space." OSHA's definition is a space that is large enough and configured in such a way that a person can enter and perform work inside, but has limited or restricted means of entry/exit, and is not designed for continuous occupancy.

Some examples are storage tanks, pits, silos, vats, degreasers, boilers, ventilation and exhaust ducts, sewers, tunnels, underground utility vaults, wells, shafts, and deep trenches.

Confined spaces can be dangerous places to work in because:

  • The ventilation is likely to be poor, and dangerous levels of air contamination or oxygen deficiency can occur. Or the atmosphere may be flammable.
  • Stored products may shift and be unstable.

There may be physical barriers to movement-and it can be difficult to get into or to remove an injured worker from the space because of the size or location of entrances and exits.

Employers whose operations may require having workers enter such potentially dangerous spaces are required by OSHA to have a written program and procedure that provide proper protection including:

  • Prohibiting entry without a permit approved by the supervisor and protecting and posting the openings to bar unauthorized entry
  • Testing the atmosphere before entry for oxygen content and for any flammable gases and vapors or toxic air contaminants and then purging the atmosphere of hazardous elements
  • Providing appropriate ventilating, lighting, and personal protective equipment for the entrant
  • Having at least one attendant on standby outside the space in continuous communication with the worker inside, wearing protective equipment, and equipped with a lifeline or harness in case a rescue is needed.
  • Arranging necessary rescue equipment, personnel, and procedures.
  • Training all workers that will be involved in any of these activities.

Workers themselves must share the responsibility for their safety when work in a confined space is required. Primarily, this involves never entering such a space without the proper permit and without knowledge that the necessary atmospheric testing has been performed and has indicated that air inside is safe to breathe with respiratory equipment if necessary. In addition, you should never enter a confined space if you are on medication or are feeling ill.

It is also important to realize that conditions inside the space can change, sometimes very suddenly. Be alert to possible changes and be ready to leave the space immediately if you begin to feel any fatigue, dizziness, or nausea. Keep in regular touch with your standby attendant and do not hesitate to call for assistance if you need to leave the space but are having any difficulty doing so.

If you are assigned as a standby, maintain continuing contact with your buddy inside and be ready to provide assistance. This does not mean entering the space yourself unless you have been specifically equipped for such rescue procedure. A large percentage of confined space fatalities have been would-be rescuers who succumbed to the same hazard that overtook the original entrant.

Although there can be many potential risks in confined space work, proper preparation, monitoring, equipment, and training can overcome them and keep workers safe. That is our purpose and with your cooperation it will be accomplished.