To that end,HSWA 1974 contained a number of general obligations of employers and the self-employed both towards their own employees and to others not in their employment, who might be affected by their work activities. These requirements were qualified by the phrase ‘so far as is reasonably practicable’. As was explained in chapter 1: introduction, this in effect required employers to carry out a risk assessment in order to identify foreseeable risks and determine what were or were not reasonably practicable precautions. chapter 17: risk assessment related concepts also explained how the process of risk assessment is fundamental in determining ‘a safe system of work’ – another basic obligation under HSWA 1974.