Re 'sûreté' and 'sécurité'....
The explanations in the earlier posts are fine, but there's one more point....
In French secondary schools, you are taught to avoid as much as possible using the same word twice in the same paragraph.
That's OK in literature, but it can be confusing, when authors of technical documentation try to apply the same rule at all cost.
It took me a few weeks (after moving to my first job in France) to understand that "tangage" and "profondeur" can be used interchangeably for "pitch" in an aeronautical context, until a French colleague explained this slightly odd habit.
So, while sûreté and sécurité are not true synonyms, don't be amazed if you discover them being used as such in the same paragraph.....