The ISO published the first part of the standards on handling of loads in 2003, the ISO 11228-1.
The method establishes the following restrictions:
- It only applies to the manual handling of objects with a mass of 3 kg or more.
- The walking speed must be moderate, between 0.5 and 1.0 m/2, on a horizontal level surface.
- It does not include the analysis of combined tasks, carried out during a shift, which lasts for 8 hours.
A step-by-step system is established to estimate the risks for health caused by load lifting and carrying tasks. Recommended limits and practical guidance are proposed for ergonomic organisation of tasks.
These three movements are considered:
- Manual lifting: Moving an object from its initial position upwards without mechanical assistance.
- Manual lowering: Moving an object from its initial position downward without mechanical assistance.
- Manual carrying: Carrying when an object remains lifted and is moved horizontally by human force.
It also proposes recommendations, bearing in mind relevant factors such as the nature of the task, characteristics of the object, work environment, and the workers’ personal capacities and limitations.