Confined Space Training Certificate PPE and Breathing Apparatus — Questions and Answers
Question 1: In the hierarchy of control measures for confined space hazards, personal protective equipment (PPE) is considered:
- The first line of defence against all hazards
- The last resort, to be used only when higher-level controls cannot adequately reduce the risk (Correct answer)
- Equally effective as engineering controls
- Unnecessary if a risk assessment has been completed
Correct answer: The last resort, to be used only when higher-level controls cannot adequately reduce the risk
PPE is at the bottom of the hierarchy of control because it relies entirely on the wearer using it correctly. Higher-level controls (elimination, substitution, engineering controls, administrative controls) are preferred because they reduce or remove the hazard at source. PPE should only be used to manage residual risk after other measures are in place.
Question 2: A filtering respirator (such as a half-face mask with cartridges) should NOT be used in a confined space when:
- The temperature inside is above 20°C
- The atmosphere is or may become oxygen-deficient or contain concentrations of gas immediately dangerous to life (Correct answer)
- The work will last less than 30 minutes
- The worker has been face-fit tested
Correct answer: The atmosphere is or may become oxygen-deficient or contain concentrations of gas immediately dangerous to life
Filtering respirators work by cleaning the ambient air — they do not supply oxygen. If the atmosphere is oxygen-deficient (below 19.5%) or contains IDLH concentrations of toxic gas, a filter cannot provide safe breathable air. In these conditions, supplied-air breathing apparatus (airline or SCBA) must be used instead.
Question 3: Face-fit testing for respiratory protective equipment (RPE) is required to:
- Check that the wearer looks professional
- Ensure the facepiece forms an adequate seal against the wearer's face, preventing contaminant leakage (Correct answer)
- Confirm the filter is the correct type for the hazard
- Verify the RPE meets British Standards
Correct answer: Ensure the facepiece forms an adequate seal against the wearer's face, preventing contaminant leakage
Face-fit testing confirms that a specific make, model, and size of tight-fitting facepiece achieves an adequate seal on the individual wearer's face. Without proper fit, contaminated air leaks around the seal, significantly reducing the protection provided. Testing must be repeated when the wearer's facial features change.
Question 4: Self-contained breathing apparatus (SCBA) used in confined spaces typically provides an air supply lasting:
- Approximately 20-45 minutes depending on the wearer's breathing rate and cylinder size (Correct answer)
- At least 4 hours of continuous use
- Indefinitely as the air is recycled
- Exactly 60 minutes regardless of conditions
Correct answer: Approximately 20-45 minutes depending on the wearer's breathing rate and cylinder size
Standard SCBA cylinders used in industrial confined space work typically provide 20-45 minutes of air, though this varies with cylinder size, working pressure, and the wearer's breathing rate. Physical exertion in rescue situations significantly increases air consumption. Duration must be factored into the safe system of work and rescue planning.
Question 5: An airline breathing apparatus (compressed air line) for confined space work must have:
- A connection to the site's standard compressed air supply used for pneumatic tools
- A supply of breathing-quality air that meets BS EN 12021, with an escape cylinder in case the airline fails (Correct answer)
- Any available air compressor regardless of air quality
- A minimum line length of 50 metres
Correct answer: A supply of breathing-quality air that meets BS EN 12021, with an escape cylinder in case the airline fails
Airline breathing apparatus must be supplied with air that meets the breathing air standard BS EN 12021, which specifies limits on contaminants such as carbon monoxide, carbon dioxide, oil mist, and water. The air source must be positioned in clean air, and the user must carry an escape cylinder providing enough air to exit safely if the airline is damaged.
Question 6: Protective clothing for confined space entry may need to include chemical-resistant suits because:
- They improve the wearer's visibility in dark spaces
- Residues, liquids, or vapours within the space may cause skin burns, absorption of toxic substances, or chemical injury (Correct answer)
- They are required by all confined space permits regardless of the hazard
- They provide better insulation against cold temperatures
Correct answer: Residues, liquids, or vapours within the space may cause skin burns, absorption of toxic substances, or chemical injury
Chemical-resistant suits protect against dermal exposure to hazardous substances. In confined spaces containing chemical residues, liquids, or vapours, skin contact can cause chemical burns, allow absorption of toxic substances through the skin, or cause sensitisation. The suit type must be matched to the specific chemicals present.
Confined Space Training Certificate PPE and Breathing Apparatus
In the hierarchy of control measures for confined space hazards, personal protective equipment (PPE) is considered: