Print Article Share Add Comment Email Article A portrait of process safety: From its start to present day

By looking at the history of process safety and the improvements that each decade has brought in terms of regulations and techniques, industry can invariably make itself safer. Determining how major incidents such as Bhopal, Flixborough, Chernobyl, Piper Alpha and others have influenced the industry, academia, government and subsequent regulations can offer a firm foundation for future endeavors. There is still research needed in the near future to further cement the foundation, and researchers and process safety experts need to pay attention to what incidents of this millennium are telling us about what is still needed in order to make process safety second nature.

Background

The 19th century is known as the era of industrial revolution. Each technical progression has brought with it a certain amount of threat and hazardous activity. Chemical process safety was not a major public concern prior to almost the end of the 18th century. However, safety concerns were always there from the beginning of industrialization but not necessarily as we know or call it today. The primitive instinct of human beings to stay alive and protect themselves is probably the most visceral driver for the growth of process safety initiatives.¹

Process safety: An ongoing phenomenon

The driving force for process safety has been primarily based on catastrophic events. With an increasing number of tragic incidents, the process industry and governments started taking initiatives to minimize loss of life and property, as well as to protect the environment. In the US, safety regulations started back in 1899 when the US government issued the River Harbor Act to avoid excess dumping in waterways. At the beginning of the 19th century, especially in the mines, thousands of innocent lives were lost because of the hostile environment. The year 1910 was reported as the worst, with 1,775 deaths in mines.² These tragedies forced governments and local establishments to initiate regulatory regimes. In order to understand the growth of process safety, we have divided the significant initiatives and incidents into three broad sections. This categorization is based on the changes that took place between years 1930–1970, 1970–2000 and 2000–2012. This is shown in Fig. 1.

Fig. 1. Broad classification of process safety   development based on time period.

From 1930–1970. This period was mostly about establishing regulations. The Walsh-Healy Public Contracts Act in 1936 in US restricted working hours and employing child labor.¹ This act also was concerned with occupational diseases, a basis of many present safety regulations. The 1947 presidential conference on industrial safety was another noteworthy step forward. Some other regulations were established in the years 1936–1969 (see Table 1). Individually, these acts did not have major impact in ensuring industrial safety but they played an imperative role for process safety to reach the position that it has achieved.


Congress passed the Occupational Safety and Health Act in 1970, which is a landmark legislation that put into motion programs that continue to evolve. Under this act, the Department of Health established the Occupational Safety and Health Administration (OSHA) with wide-ranging authority to enforce safety and health standards to ensure a safer workplace.¹ Also, the US Department of Health and Human Services instituted the National Institute for Occupational Safety and Health (NIOSH) which had the responsibility to conduct research, provide recommendations to OSHA and train professionals for increasing awareness.¹ In addition, the US Environmental Protection Agency (EPA) was established in 1970 to address environmental issues.
From 1970–2000. In the 1970s and 1980s, some of the world’s most shocking and tragic industrial accidents took place. Consequently, industries and government bodies everywhere were forced to rethink about the technology and management systems in industries from the safety point of view. Fig. 2 offers a timeline of the catastrophes during this time period.

Fig. 2. Timeline of major industrial disasters   between 1974 and 1989.

The Flixborough explosion in 1974 was by far the most severe disaster in the UK chemical industries and proved to be a major driver for process safety issues in the UK. As a result of these initiatives, at the end of 1974, the Advisory Committee on Major Hazards (ACMH) was implemented. The impact of Flixborough was reinforced by that of the Seveso tragedy in 1976.³
However, the unforgettable Bhopal gas disaster in India on December 3, 1984, which resulted in varying estimates of 3,000 to upward of 20,000 fatalities and injuries to another 500,000, was a wake-up call for the chemical process industry. Both the industry and the public became aware of the potential hazard of chemical facilities.² This piloted the intensification of efforts within industry to ensure the safety of major hazard plants. Process safety finally gained absolute recognition as a standard practice. After the Bhopal tragedy, many regulatory initiatives were taken worldwide. In India, the Environment Protection Act (1986), the Air Act (1987), the Hazardous Waste (Management and Handling) Rules (1989), the Public Liability Insurance Act (1991) and the Environmental Protection (Second Amendment) Rules (1992) were promulgated.³
In 1984, the Mexico City disaster represented the largest series of boiling liquid expanding vapor explosions (BLEVEs) in history that killed almost 500 people.³ The nuclear disaster which took place on April 28, 1986, in Chernobyl, Ukraine, killed 56 people and caused the development of cancer and radiation sickness in many.³ The Piper Alpha accident on July 6, 1988, resulted in 167 deaths. The Piper Alpha Inquiry has been of crucial importance in the development of the offshore safety regime in the UK sector of the North Sea. On October 23, 1989, in the Phillips 66 plant in Pasadena, Texas, a massive gas explosion caused the death of 23 people and more than 300 injuries. ³
These incidents made it even more evident that implementation of safety legislation was indispensably necessary. Table 2 and Table 3 show the significant legislative and regulatory steps taken in the US and Europe.

Process safety in the new millennium

Process safety has certainly made remarkable progress. However, it is still impossible to adequately answer a simple question, “Are we safe enough?” The incidents that occurred in this millennium are a reminder that process safety has a long way to go.
The Columbia disaster on February 1, 2003, caused the death of all seven astronauts onboard and scattered shuttle debris over 2,000 square miles of Texas.¹¹ This tragic incident can be traced back to flaws in decision making at NASA. The Columbia explosion was an important lesson for crisis communication professionals, as well. In fact, the NASA lessons can be mapped to many other catastrophes, such as the Piper Alpha or the Flixborough incidents, that reveal a sense of vulnerability, establish an imperative for safety, and reinforce the need for valid on-time risk assessments.¹¹
The Macondo blowout in the Gulf of Mexico (GoM) on April 20, 2010, killed 11 employees and led to an uncontrolled oil spill lasting 87 days.¹² This blowout was the most significant offshore incident in the US, and it had a profound impact on safety regulations in the GoM. The Drilling Safety Rule regarding well-bore reliability and well-control equipment was implemented on October 14, 2010. The Modified Workplace Safety Rule was put into place on October 15, 2010, based on the lessons learned from the Macondo blowout.
Finally, there was the Fukushima Daiichi nuclear plant incident in March 2011 that drew the attention of the global process and power industries, encouraging them to incorporate natural disaster risks in a hazard analysis study.¹²
Technical achievements pre-1970. Techniques to identify and evaluate hazards, calculate consequences and quantified event probabilities and risk (such as What-If, Checklist, HAZOP, Fault- and Event-Tree analyses) were developed in the middle of the 20th century. These developments occurred in some cases years or even decades before the well-known major incidents in the 1970s and 1980s. However, these catastrophic incidents reflected the need for more understanding and research regarding the underlying issues about process safety incidents. For example, the HAZard and OPerability (HAZOP) study, was developed by ICI in 1963, when a team was looking for ways to design a plant for phenol production with the minimum capital cost, but was considering possible deficiencies in the design.¹³ The Flixborough and Seveso incidents clearly showed the importance of identified hazards before fatal incidents occur, and HAZOP gained extensive popularity within operating and design companies. In the case of the Flixborough disaster, more than 40 tons of cyclohexane were released due to the rupture of a temporary bypass line. The temporary pipe was designed by a person who did not know how to design large pipes operating at high temperatures. After this incident, companies started to include procedures for management of change (MOC). Fault tree analysis (FTA) was developed in the early 1960s, and its use as a safety system and reliability technique quickly gained widespread interest, especially in nuclear and power installations. Since the development of FTAs, great efforts and advances (analytic methodologies, computer programs, computer codes) have occurred in the quantitative evaluation of fault trees.¹⁴
Technical achievements: 1970s and 1980s. In the US and Europe, models for pool formation, releases, evaporation and fire and explosions were refined in the late 1970s and the early 1980s.¹⁵ In these two decades, a series of fatal incidents (Fig. 3), reinforced the importance of these models and were one of the principal motivations for further research and improvements.

Fig. 3. Research motivated by major disasters   in the 1980s.

Bhopal increased substantially the interest and activity of the research and academic communities in a wide range of areas related with process safety,² principally in reactivity hazards (employees did not have knowledge of the reactivity of MIC mixed with water¹⁶), inherent safety and chemical releases. The 500 deaths involved in Mexico City clearly demonstrated the importance and hazards involved in BLEVEs.³ Piper Alpha focused attention on jet fires, pool fires, carbon monoxide fires (initial CO poisoning caused most of the deaths) and explosions in modules with turbulence generation.¹⁷ This incident, and the sinking of the Alexander L. Kielland in 1980, were the most important events in the history of offshore operations in Europe, and together made a great impact in the use of quantitative risk assessment (QRA) techniques to assess offshore facilities.¹⁸
The aftermath of the Chernobyl disaster gave birth to the safety culture concept.¹⁹ According to the Phillips report,²⁰ the cause of the incident was a modification in a routine maintenance procedure. This reinforced to the process industry the importance of incorporating management systems, such as MOC procedures. The 1970s and 1980s were decades of major incidents and great losses, but there is no doubt that these two decades made a great impact on what today we call “process safety.”
Technical achievements: 1990s to present day. During the 1990s, in response to new regulations and regulatory initiatives, collection of incident history data started at a rudimentary level. Advances in technology and the research conducted by different centers, such as the Mary Kay O’Connor Process Safety Center (which was established in 1995), allowed for the development and availability of increasingly reliable incident databases.²¹ In the late 1990s, the Chemical Safety Board (CSB), in its MOC safety bulletin, highlighted the importance of having a systematic method for MOC, and how this is an essential ingredient for safe chemical process operations.
In the 1990s and early 2000s, the development of engineered nano-materials increased considerably. This development introduced a new area of research to process safety, an area where researchers are trying to understand the workplace exposure and environmental aspect of nanotechnologies.

Research needed in the near future

There is no doubt that the field of process safety has made great advances in terms of regulation and techniques in the last 40 years, but industry changes every day, and more sophisticated and complex processes are developed. This, combined with factors such as human errors (which will be always present), and challenges in creating and maintaining organizational memory, among others, is the reason why incidents continue to occur. Fatal incidents in this new millennium highlighted some of the areas of process safety where research is still needed (Table 4).
Dust explosion. Dust explosion research has been conducted on and off for more than 100 years.²² However, events such as the Imperial Sugar Co. incident in Georgia (14 deaths, 14 life-threatening burns, 38 total injures²³) demonstrate the need for further research, awareness and management systems. In order to prevent these kinds of incidents, it is imperative to perform experimental and theoretical work to understand the chemistry and physics of dust cloud generation and combustion, flame propagation and potential ignition sources. It is also important to understand and develop models for fire and explosion of nano-materials.
Reactive chemicals. Reactive chemistry incidents continue to occur in the chemical processing industry, and in other industries which handle chemicals in their manufacturing processes. A CSB study, released in 2002, identified 167 reactive incidents that occurred between 1980 and 2001, which caused 108 deaths.²⁴ More experimental and theoretical research is necessary to fully understand the kinetics and thermal behavior of industrial chemical reactions.⁴
Safety culture. The tragic Columbia shuttle incident showed the possible fatal consequences of bad industrial communication. It is important that research and safety professionals understand and evaluate good safety culture that enables the sharing of information and improvement of safety within the industries, taking into account different specialties and environments.
Nuclear safety. The Fukushima incident definitely changed the risk perception of nuclear power plants. Managers and researchers have a long journey in both risk communication and risk assessment models of nuclear power plants.

Make safety second nature

Although “process safety” was not recognized as a practice or discipline before the mid-1980s, concern about the health, safety and environment is intrinsic in human beings and as old as civilization. Great advances in safety regulations and techniques have occurred during the last century. But as industry grows and changes every day, processes present new challenges. Managers, operators and researchers must continue working together to improve their overall safety knowledge in order to make safety second nature. HP

LITERATURE CITED

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³ Mannan, M.S., editor, Lees’ Loss Prevention in the Process Industries, Volumes 1–3 (3rd Edition), Elsevier, 2005.
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The authors
	M. Sam Mannan, PhD, PE, CSP, is a chemical engineering professor and director of the Mary Kay O’Connor Process Safety Center at Texas A&M University. He is an internationally recognized expert on process safety and risk assessment. His research interests include hazard assessment and risk analysis, flammable and toxic gas cloud dispersion modeling, inherently safer design, reactive chemicals and run-away reactions, aerosols and abnormal situation management.
	Amira Y. Chowdhury, BS, is a PhD student in materials science and engineering, and a research assistant at the Mary Kay O’Connor Process Safety Center at Texas A&M University. She is a chemical engineer from the Bangladesh University of Engineering and Technology. Her research interests include hazard assessment and dust explosions.
	Olga J. Reyes-Valdes, BS, is a materials science and engineering PhD student at Texas A&M University and research assistant of the Mary Kay O’Connor Process Safety Center. She is a chemical engineer from Universidad Industrial de Santander, Colombia. Her research interests include reactive chemicals and run-away reactions, dust explosion, hazard assessment and risk analysis.

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