ABSTRACT
The Requirement for a Safety Case Why Do You Need a Safety Case Anyway? Where some equipment, activity or task is recognised as being dangerous, it is usual for there to be some rules or advice about its use. This may just be as minor as some operating instructions, but perhaps there are inspectors or even a regulatory body that oversees those particular items or that particular industry. Ultimately this regulator may be the local, state or national government, which passes bills or laws prohibiting or mandating certain actions. In the UK, the government has mandated the provision of a safety case as a requirement for obtaining a licence to operate in certain high-risk industries. Several other industries have voluntarily followed suit by publishing standards explicitly requiring safety cases to be produced. In the US, OSHA's plans for reducing workplace fatalities does not mandate the use of safety cases, but it is acknowledged that companies with the best safety records have some sort of formal safety and health programme, and a key to these programmes is the annual safety plan. These plans typically have the reduction of work-related accidents as their goals, and they provide a framework for continuous improvement in safety. Within Europe as a whole, there is no explicit call for safety cases. However, in certain high risk industries there is Europe-wide legislation explicitly requiring operators of establishments coming under the scope of the relevant directives to establish a major accident prevention policy, and under certain conditions, to establish a safety report, an emergency plan and a safety management system. The safety report component of these requirements may be considered equivalent to a safety case. Legislation for Safety Cases Historical incident In 1976, the Seveso accident happened at a chemical plant in Italy, manufacturing pesticides and herbicides. A dense vapour cloud containing tetrachlorodibenzoparadioxin (TCDD) was released from a reactor, used for the production of trichlorofenol. Commonly known as dioxin, this was a poisonous and carcinogenic by-product of an uncontrolled exothermic reaction. Although no immediate fatalities were reported, kilogram quantities of the substance lethal to man even in microgram doses were widely dispersed which resulted in an
immediate contamination of some ten square miles of land and vegetation. More than 600 people had to be evacuated from their homes and as many as 2,000 were treated for dioxin poisoning. Major accidents in the chemical industry have occurred world-wide. In Europe, the Seveso accident in 1976 in particular prompted the adoption of legislation aimed at the prevention and control of such accidents. In 1982, the first EU Directive 82/501/EEC (so-called Seveso Directive) was adopted. On 9 December 1996, the Seveso Directive was replaced by Council Directive 96/82/EC, socalled Seveso II Directive. This directive was extended by the Directive 2003/105/EC. The Seveso II Directive applies to thousands of industrial establishments across Europe where dangerous substances are present in quantities exceeding the thresholds in the directive [Europa 2005]. In the UK, there are specific requirements laid down in regulations and parliamentary Acts for many industries. There really are hundreds, so only a few are presented here, if you think you are covered by any of these, you should look up the full reference for all the specific information. The Management of Health and Safety at Work Regulation 1999 specifically call, for the employer to carry out and record a risk assessment – an integral part of a safety case, although it stops short of explicitly calling for one. The Construction (Design and Management) Regulations 1994 place duties on the planning supervisor to produce a safety plan and maintain a safety file. The licences for operating a nuclear establishment, a petrochemical establishment or operating on the railways explicitly call for the provision of a safety case. For example; the Railways (Safety Case) Regulations were introduced in 1994 as a means of ensuring that health and safety standards on the railways were maintained post-privatisation. They introduced a 'permissioning' regime requiring all railway operators, as a condition of operation, to prepare a safety case setting out their health and safety arrangements. The defence industry in the UK has followed suit in the requirement for a safety case, and although it is not in legislation, it is in UK defence standards, which can be cited as legal requirements in contracts for the provision of defence equipment and services. The main standard is known as “00:56”, and it says [MoD 2006]:
9.2 The contractor shall produce a safety case for the system on behalf of the duty holder (person responsible at law for safety) … 9.5 The safety case shall contain a structured argument demonstrating that the evidence contained therein is sufficient to show that the system is safe. The (safety) argument shall be commensurate with the potential risk posed by the system and the complexity of the system.
