Safety cases major accidents

Andrew Hopkins. 1999. For whom does safety pay The case of major accidents. Safety Science. (32) 143-153. 

Lees, F. P. and Ang, M. L. (eds) (1989) Safety Cases Within the Control of Industrial Major Accident Hazards (CIMAH) Regulations 1984 (Butterworths). 

The concept of a safety case comes from the requirements of the European Union/European Community (EU/EC) Seveso Directive (82/501/EC) and, in particular, regulations that the United Kingdom and other member states used to implement that directive. United Kingdom regulations (Control of Industrial Major Accident Hazards [CIMAH], 1984 replaced by Control of Major Accident Hazards Involving Dangerous Substances [COMAH] in 1999) require that major hazardous facilities produce a safety report or safety case.64 The requirement for a safety case is initiated by a list of chemicals and a class of flammables. Like the hazard analysis approach (Section 8.1.2), experts identify the reactive hazards of the process if analysis shows that the proposed process is safe, it may be excluded from additional regulatory requirements. 

There have been numerous discussions about this accident, which produced the most casualties in the history of industrial disasters. Some arguments revolve around the direct cause of the accident. As is generally known, many major accidents have been caused by combinations of small accidents. The accident in Bhopal also happened as the result of a combination of serious mistakes the mixing of water with MIC caused by neglecting to put the metal sheet in place to separate reactive components, and the failures in operation of the exhaust gas scrubber and the flare stack. Such cases are frequently found where a safety device is temporarily removed because the device is troublesome. It is necessary to educate people that the reliability of a safety device should be tested and that the failure of a safety device can lead to unexpectedly terrible results. 

The monthly CCPS Process Safety Beacon (CCPS, Beacon) is designed for manufacturing personnel, describing actual accidents, the lessons learned, and the practical means to prevent a similar accident in other plants. Similarly, the United Kingdom s Institution of Chemical Engineers (IChemE) Loss Prevention Bulletin (IChemE, LPB) is another major source of safety case studies for the process industries. Included with each LPB issue is a Powerpoint Toolbox Talk on one... 

In the sense of the Major Accident Ordinance the safety system is an accident preventing measure and as such is safety relevant. In order to avoid as far as possible that the safety system is activated, its activation is in many cases preceded by that of a monitoring system. 

Seismic action can cause serious accidents to industrial plants as shown in several occasions. The actual worldwide situation of major-hazard plants against earthquakes should be considered as critical. For instance, in Italy about 30% of industrial plants with major-accident hazards are located in areas with a high seismic risk. In addition, in case of a seismic event, the earthquake can induce the simultaneous damage of different apparatus, whose effects can be amplified because of the failure of safety systems or the simultaneous generation of multiple accidental chains. 

Risk assessments are carried out for each site when changes occur and every 5 years even with no changes. The crane business requires that a lifting plan be made for each time lifting is done. All safety-related requests from the client are also noted and considered in the individual lifts. So far Havator has not encountered any major accidents and internal research has always been enough when accidents do occur. All investigations are documented and most of them have to do with the Nordic climate, e.g., snow and ice-related slips and falls. Hazardous incidents are also reported and presented in the meetings of the safety committee. In serious cases, information is spread and preventive actions are taken. Some of the cases are... 

The Railway Inspectorate has also been criticized for its use of risk assessment. The main criticism was an insufficient emphasis upon risk assessment procedures, for example, in its data collection and analysis and also in its approach to safety cases (HSE, 2000 t). The validity of this criticism is borne out by recent events. The Southall and Ladbroke Grove accidents demonstrate how cautiously we should approach railway statistics because of their vulnerability to major disasters. Related to this should be some caution in basing future predictions on past performance and most particularly in using this as a basis for arguing against effecting improvements. So it is important that these analyses... 

Safety eases entered the UK safety world as a result of the Control of Industrial Major Aeeidents Hazards regulations (CIMAH regulations) in 1984. Safety case principles were further examined and developed by Lord Cullen in his report into the Piper Alpha disaster (Cullen 1990) in which a major accident in an offshore oil facility in the North Sea resulted in 167 deaths. As a result of this report, the approach to offshore safety shifted from compliance to achievement of safety objectives. A safety case would demonstrate through argument and evidence that the required safety objectives would be met. Regulations laid down what must be addressed in a safety case. 

In other words, companies which have a good occupational safety record can still experience a catastrophic process safety-related event. Improvements in personal safety do not necessarily reduce the chance of a major accident from occurring, although the reverse is less likely to be the case a company that has a strong process safety program is likely to also have good occupational safety results. 

In the UK, the Seveso Directives led to the creation of the Control of Industrial Major Accident Hazards (CIMAH) regulations in 1984. These regulations required manufacturers of hazardous chemicals to create a Safety Report— in effect a Safety Case. They also had to show how the hazards were being effectively managed. CIMAH was replaced by Control of Major Accident Hazards (COMAH) in 1999. 

Although a Safety Case can and should cover aU aspects of safety (occupational, process, and technical, as described in Chapter 1) the focus tends to be on identifying and avoiding what are known as Major Accident Events (MAE), i.e., catastrophic events such as fires, explosions, and the release of toxic chemicals. Associated with Major Accident Events are Safety Critical Elements and Performance Standards. 

But the impact of Deepwater Horizon/Macondo went beyond the United States the accident caused oil companies all over the world to think through the effectiveness of their safety management programs. Moreover, events such as the Montara blowout in Australian waters in the year 2009 showed that these events are not confined to one place. The contents of this book therefore go beyond the United States regulatory environment. The book describes some of the major offshore incidents that have occurred over the last 40 years or so, some of which occurred onshore, that led to the development of modem safety management systems and regulations. So, for example, it contains a thorough discussion of the Safety Case approach—a system that was first used in the North Sea but that has now spread to many international locations. 

In many applications it is necessary to produce a safety case outline by the operator prior to developing a safety case. (Ref MHF regulation). MHF stands for major hazard facilities (such as oil refinery, chemical plants). MHF regulation is applicable for working in these facilities in Australia, and for working safe in these areas there are some obligations to be met with. In UK similar regulation is in place in the name of control of major accident hazards (COMAH). 

It is necessary to identify all hazards that could lead to a major incident/accident. However, this is an endless task, so the operator (who is conducting the study) is required to set the boundary for each study. If there are no possibilities, because of any activity/procedure at the facility being escalated to a major incident/accident, then these can be excluded from the study. However, this is not arbitrary Anything that is kept outside the boundary must be properly recorded with suitable reasons for demonstrating the safety case. 

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