Article 6 February 2023

Categories of work, and selection of equipment

This is the second of our ‘deep dive’ series, covering the categories of work and selection of equipment when Working at Height. 

Working at height categories
WaH can be identified and linked with equipment, in two risk-based categories; Cat 1 being Low Risk and Cat 2, High Risk.

Category 2, High Risk rules mandate that:

  • The task ‘cannot’ be de-risked to Cat 1;
  • All persons WaH and intrinsic to the safe delivery, must have an in-date medical;
  • An Appointed Person (AP) must be assigned who will review and approve the Safe System of Works and issue an Authority to Work;
  • All involved must meet the SKET requirements set out in the WaH procedure;
  • A rescue plan must be constructed, tested and communicated.

Category 1, Low Risk rules mandate that;

  • Cat 1 ‘can’ be escalated to Cat 2;
  • All involved must meet the SKET requirements set out in the WaH procedure;
  • The requirement for a medical must be assessed on a task-by-task basis;
  • The requirement for a rescue plan must be assessed against the requirements of the procedure.

Whether Cat 2 or Cat 1, a Dynamic Risk Assessment and Task Brief must be completed prior to any works.

Category Escalation & Selection of Equipment

The circumstances in which a Cat 1 activity can be escalated to a Cat 2 include:

  • The environment poses additional hazards;
  • Other activities are taking place that could impact of the safety;
  • The task to undertaken (whilst at height), are defined as high-risk;
  • Client’s access equipment is being used.

For example, a fixed ladder on a client site may result in an AP being involved.  The AP will provide assurance that kit is suitable for the task and that is has been maintained properly ‘prior’ to agreeing that it can be used as part of the Safe System of Work.  For a full list of considerations see the WAH Instruction Manual.

To support this, we have revised the Access / Fall Selection Tool (Access Fall Prevention Selection Tool_MG(HSOH)091F.xlsx ( which allows the user to score equipment against a range of factors including, security, handling, environment, persons, the task and the cost.  The score will result in:

  • Lowest score being the most suitable, in most circumstances;
  • Flagging possible escalations to Cat 2;
  • Qualification of escalation, additional controls and final selection.

The form must be reviewed and accepted by an AP before the safe system of work is mobilised.  For further advice contact your local QHSE colleague or for any procedural, document feedback please use the IMS.

If you require any support, please contact a member of the QHSE/SSOW teams!