Calculation of approriate Category Level - H&R - Common

  • All hazards are classified as ‘Serious’ (S2).
  • The Frequency classification may be either F1 or F2, depending on the specific application.
  • All hazards are avoidable and can be classified as P1.
  • For usage that is ‘seldom to quite often’ (blue line), a safety level of Cat1 or Cat2 may be appropriate.
  • For ‘frequent to continuous use’ (red line) the machine should be monitored to a Cat3 level.
  • This is offered as a general guide only.
  • Some companies have a policy that all new equipment be monitored to Cat3 or higher.

HRA Hazard Categorisation Flowchart

SSeverity of injurySelection of Categories B, 1 - 4
S1SlightHRA Diagram SymbolPreferred categories for reference points
S2Serious (normally irreversible) injury, including death
FFrequency and/or Duration of exposure to the Hazard
F1Seldom to quite often, and/or short exposure timeHRA Diagram SymbolPossible categories which may require additional measures
F2Frequent to continuous and/or long exposure time
PPossibility of avoiding the HazardHRA Diagram SymbolMeasures which can be over-dimensioned for the relevant risk
P1Possible under certain circumstances
P2Nearly impossible to avoid the hazard