CITB Specialists Confined Spaces & Noise 1 — Questions and Answers
Question 1: How is a 'confined space' defined under the Confined Spaces Regulations 1997?
- A place which is substantially enclosed and where there is a reasonably foreseeable risk of serious injury from hazardous substances or conditions (Correct answer)
- Any space less than 2 metres in any dimension
- Any underground space on a construction site
- Any space requiring special access equipment to enter
Correct answer: A place which is substantially enclosed and where there is a reasonably foreseeable risk of serious injury from hazardous substances or conditions
A confined space is defined as a place that is substantially enclosed (though not necessarily fully enclosed) where there is a reasonably foreseeable risk of serious injury from hazardous atmosphere, engulfment, or other specific dangers due to the nature of the space.
Question 2: What is the first principle of working in confined spaces?
- Avoid entry if possible — find an alternative method to do the work without entering (Correct answer)
- Always send the smallest person in first
- Enter quickly to reduce exposure time
- Use the longest available lanyard
Correct answer: Avoid entry if possible — find an alternative method to do the work without entering
The hierarchy for confined space work starts with avoidance — can the work be done without entering the space? Only if entry is unavoidable should entry procedures be developed. This avoidance principle is fundamental to the Confined Spaces Regulations 1997.
Question 3: What atmospheric tests must be carried out before entry to a confined space?
- Oxygen level, flammable gases, and toxic gases (especially carbon monoxide and hydrogen sulphide) (Correct answer)
- Temperature and humidity only
- Carbon dioxide level only
- Light levels and noise only
Correct answer: Oxygen level, flammable gases, and toxic gases (especially carbon monoxide and hydrogen sulphide)
Before confined space entry, the atmosphere must be tested for oxygen deficiency/enrichment (should be 20.9%), flammable gases (below 10% LEL), and toxic gases including CO and H2S. Testing must be repeated during prolonged entry.
Question 4: What does 'stand-by person' mean in confined space operations?
- A person stationed outside the confined space to raise the alarm and initiate rescue if the entrant is in difficulty (Correct answer)
- A person inside the confined space as a buddy
- A person on standby to take over work when the entrant tires
- A supervisor monitoring from the site office
Correct answer: A person stationed outside the confined space to raise the alarm and initiate rescue if the entrant is in difficulty
A stand-by person must be stationed outside the confined space throughout entry operations. They monitor the entrant, maintain communication, and raise the alarm and initiate rescue procedures if the entrant is in difficulty, without entering themselves unless trained.
Question 5: Why should a rescuer never enter a confined space without proper equipment when a colleague collapses inside?
- The same atmosphere that overcome the original entrant will incapacitate the rescuer, making the situation worse (Correct answer)
- Rescuers are not trained for confined space work
- The regulation prohibits any unplanned entry
- Only fire service personnel may enter after a collapse
Correct answer: The same atmosphere that overcome the original entrant will incapacitate the rescuer, making the situation worse
Most confined space fatalities occur when untrained rescuers enter to help a colleague and are overcome by the same hazardous atmosphere. Rescue must only be undertaken with proper equipment, procedures, and trained personnel.
Question 6: At what level is oxygen concentration considered dangerously deficient?
- Below 19.5% (Correct answer)
- Below 18%
- Below 15%
- Below 10%
Correct answer: Below 19.5%
Oxygen concentration below 19.5% is considered oxygen deficient and dangerous for entry. The normal atmospheric level is approximately 20.9%. As oxygen drops, impaired judgment, unconsciousness, and death follow rapidly.
CITB Specialists Confined Spaces & Noise 1
How is a 'confined space' defined under the Confined Spaces Regulations 1997?