The annex counts as a risk efforts that are too frequent or prolonged, insufficient rest, excessive distances and a pace set by a process you cannot adjust.
How many lifts per minute (INSST guide, ISO 11228-1)
The risk is high if these frequencies are exceeded:
| Frequency | Task duration |
|---|---|
| More than 15 per minute | Up to 60 minutes, followed by at least 60 of rest |
| More than 12 per minute | Up to 120 minutes, followed by at least 30 of rest |
| More than 10 per minute | More than 2 hours |
What helps
- Breaks and rotation between tasks with different demands.
- That you, not the machine, set the pace whenever possible.
In practiceOn a parcel conveyor that never stops, each operator lifts 12 boxes a minute all
morning. At that frequency the guide calls for rotation or rest: it is a job for the assessment, not for your stamina.
Source: Real Decreto 487/1997, sobre manipulación manual de cargas (manual handling of loads; consolidated text, in Spanish), annex, point 4 · INSST, Guía técnica de manipulación manual de cargas (technical guide, 2024 edition, in Spanish), comments on the annex, point 4, table 4