ISO/TR 14121-2 was prepared by Technical Committee ISO/TC 199, Safety of machinery.

This second edition cancels and replaces the first edition (ISO/TR 14121-2:2007), which has been revised as follows:

- the examples previously given in Annex A, as well as the description of quantified risk estimation, have been deleted;
-  the explanations of the methods or tools, taken from Annex A, are now presented in 5.3.5 for hazard identification and 5.4.4.1 for risk estimation;
- the terminology and criteria have been revised;