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Confined Space Entry

Essential guidance for controlling atmospheric hazards, isolating energy, managing safe entry and preparing an effective rescue arrangement.

OSHA10 min readHigh Risk

Overview

Confined spaces are not designed for continuous occupancy, may have restricted entry or exit, and can contain serious atmospheric or physical hazards. Entry should take place only after hazards are evaluated, the space is isolated, acceptable atmospheric conditions are established and the permit process is completed.

Main Hazards

  • • Oxygen deficiency or oxygen enrichment
  • • Toxic or flammable atmosphere
  • • Unexpected energy or product release
  • • Moving mechanical equipment
  • • Engulfment, entrapment or crushing
  • • Restricted entry and exit
  • • Heat stress and inadequate ventilation
  • • Unprepared or delayed rescue response

Required PPE

  • ✓Safety helmet
  • ✓Safety footwear
  • ✓Suitable gloves
  • ✓Eye and face protection
  • ✓Full-body harness where retrieval is required
  • ✓Respiratory protection when specified by the assessment

Essential Controls

  1. 1Evaluate the space and determine whether it is a permit-required confined space.
  2. 2Prepare and authorize an approved confined-space entry permit before entry.
  3. 3Isolate all energy, pressure, chemical and product sources.
  4. 4Test the atmosphere before entry and throughout the work using suitable instruments.
  5. 5Provide continuous and adequate mechanical ventilation when required.
  6. 6Maintain a trained attendant outside the space for the duration of entry.
  7. 7Provide reliable and continuous communication with authorized entrants.
  8. 8Prepare a practical rescue plan with suitable equipment, competent personnel and response methods.

Common Mistakes

  • ×Testing the atmosphere only before entry
  • ×Relying only on closed valves for isolation
  • ×Assigning unrelated duties to the attendant
  • ×Entering without a workable rescue plan
  • ×Using a gas detector without valid calibration or bump testing
  • ×Failing to reassess the permit when conditions change

Pre-entry Checklist

  • ✓The space has been classified and hazards evaluated
  • ✓The entry permit is approved and available at the entry point
  • ✓LOTO and mechanical isolations have been verified
  • ✓The gas detector has been checked and readings recorded
  • ✓The ventilation system is operating
  • ✓Entrants, attendant and entry supervisor have been identified
  • ✓The communication method has been tested
  • ✓Rescue equipment and rescue personnel are ready

Rescue Readiness

A rescue plan must be workable, not merely documented. Before entry, verify the rescue method, equipment suitability, response time, communication arrangements and the availability of retrieval systems such as a tripod or winch where required. The attendant must not enter the space to attempt an unauthorized rescue.

OSHA References

OSHA 1910.146OSHA 1926 Subpart AAOSHA 1926.1204OSHA 1926.1211

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