The Nimrod Review - Official Documents

9.7
9.8
Chapter 9 – Background to Safety Cases
innovation on the one hand but be effective against lack of precaution on the other”. 12 Such regulations are
known as “goal-setting regulations” 13 since this is what they do, rather than prescribe solutions. In explaining
why goal-setting regulations are to be preferred to prescriptive rules, Lord Cullen expressed himself to be in
agreement with the following words of the (then) Chairman and Managing Director of Conoco (UK) Ltd: 14
“It is my fundamental belief that safety cannot be legislated, while recognizing that enough
legislation or regulation needs to exist to ensure that minimum standards are maintained.
Such regulation should impose a duty on the operator to do everything reasonable to
achieve a safe operation. By and large, safety has to be organized by those who are
directly affected by the implications of failure. These people are in the best position to
determine the detailed measures necessary on their own particular installation to achieve
the safety objective. Imposition of detailed requirements cannot anticipate all the variances
of differing practice, location, organization and size that exist. In fact, prescriptive
regulation or over-detailed guidance may at times result in the overall objective actually
being compromised. Innovation, on-going improvement and objectivity will be stifled; and
the more prescriptive the regulation the more unclear it is who has the responsibility for
total safety. Compliance becomes the overriding objective. Sight is lost of the more realistic
and overall intent that all reasonable steps should be taken to achieve the total safety of
the installation.” (emphasis added)
This “goal-setting” approach finds legislative expression in sections 2 and 3 of the HSWA. These impose on an
employer a duty “to ensure, so far as is reasonably practicable, the health, safety and welfare at work of all his
employees” and “to conduct his undertaking in such a way as to ensure, so far as is reasonably practicable, that
persons not in his employment who may be affected thereby are not thereby exposed to risks to their health or
safety” (emphases added). Herein lies the origin of the principle, discussed further below, that risks should be
reduced to a level that is as low as reasonably practicable (ALARP). 15
The HSWA established the Health and Safety Commission (HSC) as the body responsible for effecting the
general purposes of the Act and the Health and Safety Executive (HSE) as the body generally responsible for the
enforcement of health and safety legislation and for exercising on behalf of the HSC such of its functions as the
HSC directed it to exercise. I refer below to some of the guidance that has since been produced by the HSE in
relation to Safety Cases and the application of the ALARP principle.
Formal Safety Assessment
9.9 In the Piper Alpha report, Lord Cullen provided a detailed description of what he meant by a “formal safety
assessment” (FSA), explaining that it involved the identification and the assessment of hazards over the whole
life cycle of a project from the initial feasibility study through the concept design study and the detailed design
to construction and commissioning, then to operation, and finally to decommissioning and abandonment. The
techniques available to be used were said to include hazard and operability (HAZOP) studies; quantitative risk
assessment (QRA); fault tree analysis (FTA); human factor analyses; and safety audits. Lord Cullen explained that
the need for FSA arose because the combinations of potential hardware and human failures are so numerous
that a major accident hardly ever repeats itself. A strategy for risk management is, therefore, required to address
the entire spectrum of possibilities. 16 Lord Cullen was, however, not prescriptive as to how precisely an FSA
should be carried out in any particular case.
9.10
The first regulations in the United Kingdom to refer to such a formal safety assessment in the form of a ‘Safety
Case’ were the Control of Industrial Major Accidents Hazards Regulations 1984 (CIMAH Regulations), which
12 Cullen, paragraph 16.36.
13 Cullen, paragraphs 17.63 and 21.39
14 Cullen, paragraph 21.4.
15 It should be noted that the HSWA does not apply to aircraft in flight: see section 15(9) of the HSWA. As explained below, however, the MOD has
nonetheless adopted the ALARP principle.
16 Cullen, paragraph 17.3.
165