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HK Confined Space Certified Worker study materials
HK Confined Space Certified Worker study resources

HK Confined Space Certified Worker: Personal protective equipment and respiratory protective equipment

HK Confined Space Certified Worker · Work through your exam, one topic at a time.

All guide sections

Personal protective equipment and respiratory protective equipment

This domain tests selection and limitations of personal protective equipment and respiratory protective equipment. The exam often presents a worker wearing the wrong respirator in an oxygen-deficient or unknown atmosphere.

PPE and RPE rules

PPE is the last line of defence; it does not replace testing, isolation or ventilation. For confined space entry, typical PPE is a full-body harness with retrieval line, helmet, safety footwear, gloves, eye and face protection, flame-retardant clothing and hearing protection where needed; lighting and tools should be intrinsically safe. A harness must be compatible with the tripod or winch and worn so the retrieval line can lift the worker without injury.

RPE selection turns on the atmosphere. Filtering respirators are acceptable only when oxygen is at least 19.5 percent, the contaminant is known, the concentration is below the immediate danger to life or health level and the filter is suitable. In confined spaces, supplied-air respirators with an escape cylinder or self-contained breathing apparatus are common; escape sets are for escape, not entry. Fit testing, pre-use checks, training, maintenance and a buddy system are mandatory in practice.

Worked example

A worker enters a pit reading 18.7 percent oxygen while wearing a P3 half-mask. The mask is useless because a filter cannot add oxygen; the worker must leave, the space must be ventilated and retested, and re-entry requires supplied air or SCBA. The reasoning is that the hazard is oxygen deficiency, not particulate concentration.

Traps that cost marks

  • Wearing an air-purifying respirator in oxygen deficiency or an unknown atmosphere.
  • Choosing a cartridge for a gas it does not remove, or ignoring breakthrough.
  • Using SCBA without fit testing or without planning exit before the cylinder runs out.
  • Wearing a harness without a retrieval line, or a line that cannot be operated from outside.
  • Using non-intrinsically-safe lamps or phones.
  • Sharing RPE without cleaning and inspection.