
Process Safety Management is the application of management systems and controls (standards, procedures, programs, audits, evaluations) to a manufacturing process in a way that process hazards are identified, understood and controlled so that the process related injuries and incidents are prevented. This requires a sustained effort by leadership at all levels.
Process Safety Management is targeted at the prevention of catastrophic events which can result in a large number of fatalities and injuries, significant environmental and health damage, significant property damage, business interruption, loss of the right to operate, and resulting high costs that can jeopardize the existence of the business.
A well implemented PSM system results in a well operated, reliable and well maintained facility, producing low cost quality products.
The process safety can be described as a blend of engineering and management skills focused on preventing catastrophic accidents and near misses, particularly structural collapse, explosions, fires and toxic releases associated with loss of containment of energy or dangerous substances such as chemicals, oil & gas and petroleum products.
The importance of PSM to Organization & leadership team is that they become fully aware of the hazards and risk potential of their plant & processing activities and their possible impact on safety, reputation and business risk to people, assets and surroundings.
Its elements can be described majorly under Personnel, Facility & Technology categories with total of 14 elements as shown in picture.
The PSM elements / attributes which we can connect are as shown.
There are different studies which are carried out at various stages of Project life cycle such as HAZOP, PHA, Dispersion study (QRA), LOPA, What if, FMEA etc. Industry practices for such studies at various project stages can be seen here in picture.
Need for PSM
Process safety management is widely credited for reductions in major accident risk and improved process industry performance. Process safety practices and formal safety management systems have been in place in some companies for many years.
Over the past 20 years, authorities mandates for formal process safety management systems in many countries and elsewhere have prompted widespread implementation of a management systems approach to process safety management.
PSM was developed after the lessons from several major accidents showed that such events can be difficult to prevent using the traditional occupational health and safety approach, which tends to focus on the interface between the individual operator and the equipment or process.
Many of the key decisions which lead to serious, unplanned events are beyond the control of the operator or even local site management. Effective control, therefore, calls for a much broader review of the process, including equipment, procedural and organizational factors, together with a management system to ensure all hazards thus identified are properly managed throughout the life of the process, regardless of changes in the personnel, organization or operating environment. The value / importance of PSM is understood from figure here.
Instances / Examples for PSM
There are few very highlighted incidents / accidents occurred in past. From PSM point of view, one can find lead to any one or more PSM elements were ignored / neglected in such incidents as listed. It also enlists some details and outcome of such instances.
Flixborough, UK (June 1974)
Partial oxidation of cyclohexane
Catastrophic failure of temporary 50 cm diameter piping
40 tons of hot cyclohexane released in 30 seconds
Vapor cloud explosion resulting 28 fatalities, 53 injuries; 1800+ houses damaged; plant destroyed
18 of those fatally injured were in control room
Hastened passage of UK “Health and Safety at Work Act”
Seveso, Italy (July 1976)
Runaway reaction
2 kg of dioxin release from relief system
Over 17 km2 affected
Locally grown food banned for several months
Several inches of topsoil removed, incinerated
80,000 animals died or slaughtered
Plant shut down and destroyed
EU “Seveso Directive” prompted
Mexico City, Mexico (November 1984)
Large LPG / fuels storage facility
Fires, vessel ruptures, boiling-liquid-expanding-vapor explosions (BLEVEs)
Initiating cause unknown
600 fatalities, 7000 injuries
Horizontal tanks rocketed as far as 1200 m away
Fixed fire protection destroyed by blasts
Fuel terminal destroyed
Bhopal, India (December 1984)
Worst disaster in Industrial safety history
Pesticide production facility
Water introduced into methyl isocyanate storage
MIC toxic vapor release from vent system
2000 to 3000 early fatalities; ~200,000 injuries
Plant shut down; Union Carbide eventually sold
Seveso II, EPA Risk Management Program prompted, Indian Factory Act amendment initiated
Toulouse, France (September 2001)
Ammonium nitrate storage at fertilizer plant
Explosive decomposition initiated; cause unknown
Equivalent blast energy 20-40 tons of TNT
30 fatalities; 2500+ injuries; US$ 2 billion in losses
Texas City, Texas (March 2005)
Refinery isomerization unit
One valve not opened during unit re-start
Release of hot flammable material from blowdown
Ignition and vapor cloud explosion
15 fatalities, 170+ injuries; BP losses and impacts
The journey of Process Safety is continuous and with improvements. Join us with this footsteps of PSM.