Process Safety Assessments

Audits are a fundamental feature of all successful management programs. It is vital that line managers know how they are performing, and senior management needs a means of checking that all the rules and standards are being followed.

With regard to process safety the phrase, “There is always news about safety, and some of that news will be bad” is frequently heard. Audits are needed in…

The Silent Parrot

This silly story does have a point that is relevant to process safety professionals. It is important not to jump to conclusions — not to be prejudiced — where the word prejudice means literally “pre + judge”, as discussed in Safety Moment #22: Clear Your Mind of Cant and the ebook Incident Investigation and Root Cause Analysis.

A man decided to buy a parrot that could talk. So he went…

White Whales and Black Swans: the Revised BSEE Drilling Rules

This article from the online journal The Hill makes some pointed criticisms to do with BSEE’s rolling back of regulations that were introduced following the Deepwater Horizon/Macondo explosion and fire. It states,

The Deepwater Horizon disaster laid bare the unfortunate reality of decades of insufficient oversight. Multiple investigations pointed to a deficient…

The Risk Management Professional

The picture at the top of this page is of Admiral Rickover (1900-1986), often referred to as father of the nuclear navy. The ships he controlled were powered by nuclear reactors and were often armed with nuclear missiles. He knew that the first accident with a nuclear ship would also be the last accident - there would be no tolerance for mistakes or accidents of any kind. The stringent…

Process Safety and Railroads

One of the themes of these Safety Moments is that different industries have much in common. Therefore, a safety program that works for one industry is likely to be useful and relevant in another. Certainly, each industry has its own specific issues that are not shared with others (some of these are described in Safety Moment #8: “But We’re Different, You Know”). But, as a generalization,…

The Risk Management Consultant

The material in this post is extracted from Chapter 20 of the book Process Risk and Reliability Management and from the ebook The Risk Management Professional.

No organization, regardless of its size, can have expertise on all aspects of the industry in which it works. There will always be specialized areas in which they will need outside help. Which means that they will need…

Where Then Shall (Process Safety) Wisdom Be Found?

Safety Moment #22: Clear Your Mind of Cant quoted the Yale professor, Harold Bloom. His insights are used again in this article.

Information is endlessly available to us; where shall wisdom be found?

His insight can be paraphrased on the following lines,

Technical information is endlessly to us (mostly from the Internet);…

Hyperloop Generic Safety Study

In Safety Moment #8: “But We’re Different, You Know” we show that risk analysis techniques have much in common across different parts of the process and energy industries. Lessons can be shared across industries such as oil refining, chemicals manufacture, pipeline operations and offshore oil and gas production. But, given that the first word in the phrase Process Safety Management (PSM) is…

The Case for Safety Cases

The Deepwater Horizon/Macondo catastrophe in the Gulf of Mexico (GoM) in the year 2010 demonstrated the need for new safety management regulations. The draft regulations went through various iterations, and the name of the responsible government agency changed twice. In the end, the SEMS (Safety and Environmental Management System) regulation became a requirement for offshore oil and gas…

The Cruise Ship’s Galley

A process safety expert and his wife went on a cruise. Part of the cruise included a tour of the ship’s impressive galley and food-serving facilities. The tour was led by one of the ship’s sous chefs.

The process safety expert realized that he was looking at a small chemical plant. In front of him were processes that involved chemical reactions, heat exchange and moderately high…

Not the Whole Truth

Safety professionals are rightly making increasing use of photographs and videos to train and educate the workforce, and to analyze incidents. In particular, security cameras often provide a fine record of an event as it unfolds.

However, it is important to be careful. Not only can images be deliberately changed, but the camera may not record everything of relevance. The following set…

The Plural of Anecdote Is Not Data

John Michael Greer Abstraction and Reflection

The author John Michael Greer published two interesting and related posts: A Rhetorical Education and The Twilight of Authority. In them he draws a distinction between two ways of thought: Abstraction and Reflection. He explains them as follows.

Use of Safety Moments

You are welcome to use our Safety Moments in your workplace. However please note the following restrictions:

The material is copyright Ian Sutton. Normal copyright and fair use restrictions apply. Inform the audience that you received the Safety Moment from the Sutton Technical Books site. You cannot sell the Safety Moment or use it for commercial purposes.

After you have…

Ford’s Missing AND Gate

Credit Reuters Update to the Update Antonov An-124 

Ford management has made a huge effort to get around the problem created by having just the one supplier of a critical component. And they were successful. They even used the enormous Antonov An-124 freight carrier to fix the problem as quickly as possible. In process safety terms, it could be said that their emergency response…

Behavior-Based Safety

Behavior-Based Safety Overview

A behavior-based safety (BBS) program aims to make permanent changes in the manner in which people work. Safety becomes a way of life that is baked into everyone's behavior. It is important to recognize, however, that a BBS program does not attempt to chance who a person is, and it most certainly is not a pop-psychology program. The program is directed just to a…

Lowest Level of Risk (BSEE)

Overview (BSEE Risk)

As part of its Well Control Rule BSEE appears to have made a major change in the manner in which offshore risk is to be managed. Section 250.107(a)(3) states,

[y]ou must protect health, safety, property and the environment by utilizing recognized engineering practices that reduce risks to the lowest level practicable when conducting design,…

Event Tree Analysis


Event Tree Analysis (ETA) uses the same logical and mathematical techniques as Fault Tree Analysis. However, whereas a fault tree analyzes how an undesirable top event may occur, an event tree considers the impact of the failure of a particular component or item in the system, and works out the effect such a failure will have on the overall system risk or reliability. Event trees use…

Safety and Environmental Management Systems (SEMS)


Following the Deepwater Horizon/Macondo catastrophe in the year 2010 it became clear that substantial improvements were needed to offshore safety management in the United States. The framework of a new rule was already available as API RP 75 - Development of a Safety and Environmental Management Program for Offshore Operations and Facilities (SEMP). This standard was used as the…

Prestartup / Operational Readiness Reviews

The purpose of a Prestartup/Operational Readiness Review (PSR) is to ensure that initial start-ups, or start-ups following major project work, proceed safely and smoothly. As with most process safety activities a PSR will generally be performed by a small team made up of representatives from operations, maintenance, engineering, and safety.

The terms ‘Operational Readiness Review’ and…

History of Safety Management in the Process Industries


History Safety Management: we have published a 30 minute video package that shows how safety management systems in the process and energy industries have developed during the course of the last 300 years. The YouTube video shown at the end of this page provides a short extract.

Historical Sequence

We can look at the development of the history of industrial safety programs using…

NORM - Naturally Occurring Radioactive Material

The material in this article is taken from Chapter 15 (Health) of the 2nd edition of Plant Design and Operations.


NORM Naturally Occurring Radioactive Material is found in many naturally-occurring materials, including some oil and gas deposits.

Sources of NORM include:

Uranium; Thorium;  Radium; and Lead-210

When NORM is transported to the…

Hard Times for Culture Change

There has been much discussion in recent years as to how to develop new and improved cultures within the process industries. There appears to be an implicit assumption in these discussions that ours is the first generation to wrestle with the problem of creating a new culture. Nothing could be further from the truth. Indeed, it can be instructive to examine how previous generations affected…

Hydrogen Sulfide (H2S)

Hydrogen Sulfide

Hydrogen Sulfide is a highly toxic chemical compound that is found in a wide variety of oil processing operations. High concentrations of H2S may be present in crude oil, molten sulfur, tank and pit-bottom sludge and produced water, all of which may release H2S when agitated, heated, or depressurized. Typical operational activities where personnel may be exposed to H2S…

Standard Examples

We have developed a set of process safety management standard examples that are used to illustrate some of the concepts and ideas developed in our publications. 

Example 1 - Facility Design

A process consists of four operating units and a utilities section. A schematic of the system is shown in Figure 1.


Figure 1 - Facility Design Example 2 - Process Flow


That would be telling

The Kletz Legacy

One of the founders of the process safety discipline was Trevor Kletz (1922-2013). Probably his best eulogy is also the simplest, "He saved lives."

As we reflect on Trevor's contributions it is clear that one of his greatest gifts was that of telling stories. He wrote extensively on technical topics such as hazards analysis and inherent safety, but he is probably best…

Risk Perception

The material in this article to do with risk perception is taken from the book Process Risk and Reliability Management.

Oscar Wilde

Risk perception is fundamentally a subjective matter; no matter how hard analysts strive to make the topic objective the fact remains that, as Oscar Wilde  (1854-1900) once said, A truth ceases to be a truth as soon as two people perceive it. 

Pressure Tests

The material in this article has been extracted from the book Plant Design and Operations.

After a piece of equipment or piping that operates under pressure has been opened and then reassembled (buttoned up) it must be pressure tested before being put back into service.

There are two types of pressure test. The first is a tightness or leak test, performed after the equipment…

Flammable and Combustible Materials

The material in this article is extracted from Chapter 1 of the 2nd edition of the book Plant Design and Operations and in the ebook 52 Process Safety Moments.

A hazard that is of great concern to virtually all process facilities is fire — most of the materials being processed, stored or transported are flammable and/or explosive. Therefore, when designing a process facility, the…

Stairways and Ladders

The material in this article is extracted from Chapter 2 of the 2nd edition of book Plant Design and Operations.

When developing the layout for a facility it is very important to ensure that personnel can move around quickly and safely using stairways, ladders, platforms and ramps. They should also be able to use the stairways and ladders to move maintenance equipment and tools, as…

Safety Signs

The material in this Article is extracted from Chapter 16 (Human Factors and Ergonomics) of the book Plant Design and Operations.

Guidance as to the types of signs and their meanings is provided below.


Prohibition signs mean "You must not" or "Do not do . . ." or "Stop". Signs of this type have a red circle, a white interior and a red bar, as illustrated in Figure…

Fire Types

The material in this article is taken from Chapter 12 of the 2nd edition of the book Plant Design and Operations.

The first step in the design and development of a system to prevent, control and extinguish fires is to identify the various release scenarios that could lead to an explosion and/or fire. This is often done through use of a hazards analysis technique such as HAZOP (Hazard and…

Lockout Tagout

Lockout / tagout systems are routinely used to protect workers when they are working with or close to hazardous systems. They are typically used in conjunction with the other isolation methods. Once a switch or valve is in the correct position it is locked so that it cannot be moved, and a 'Do Not Operate' tag is attached to it. (Valves are often chained in place, with the lock being used to…

Two Too Many Common Causes

Note: The writer does not possess special knowledge of the nuclear power industry, has not worked in a nuclear power plant and is relying entirely on public information gleaned mostly from the Internet to write this material. Hence it is more than likely that many of the thoughts and conclusions presented here will have to be updated or changed as new data or insights are provided.


Human error rates can be modeled using a technique known as THERP (Technique for Human Error Rate Prediction). The method uses Boolean logic to model and predict human error rates. Hence it can be integrated Probabilistic Risk Assessment techniques - particularly Fault and Event Tree analysis.

A THERP analysis is most effective when the tasks are routine and proceduralized, and when…

Confined Space Entry

Confined Space Entry

A Confined Space is a space which is large enough for a worker to enter but has limited openings for entry and exit and is not intended for continuous employee occupancy. Entry is considered to have occurred as soon as any part of the entrant's body breaks the plane of an opening into the space. Therefore it is not permissible, for example, to take a quick breath and to…

Fault Tree Analysis

Risk Analysis

Risk can be analyzed in one of two basic ways: inductively or deductively, that is either bottom-up or top-down.

In a deductive analysis a top-level system failure is postulated. The analyst then works backwards to deduce what combinations of events could have occurred for the system failure to have taken place (a detective solving a crime is thinking deductively). Fault…

Acceptable Risk

Fundamentally risk is subjective; it is not possible to dispassionately define what level of risk is acceptable and what is not. Any two risk scenarios are inherently different from one another due to people’s inherent understanding and acceptance of different types of risk.

The subjective component of risk becomes even more pronounced when the perceptions of non-specialists,…

Pig Launching and Retrieving

This article provides guidance to do with the launching and retrieving of pipeline pigs (also known as scrapers or tools).

Pig Launching

Below is a schematic of a launcher.

In normal operation the fluid (liquid or gas) moves along the line from left to right through the open Main Line valve. The kicker and isolation valves are both closed hence the barrel of the pig launcher…

Equipment Isolation Methods

Isolation Methods

Positive isolation methods are those which remain effective even if there is equipment failure or operator error. These techniques apply not only to vessels, piping and tanks but also to pneumatic and hydraulic equipment.

The sketch shows some of the various isolation techniques that can be used to protect workers in the process industries. The process containing…

Siting and Layout of Process Facilities


Siting and Layout: The words ‘siting’ and ‘layout’ are often used interchangeably, but, strictly speaking, they have different meanings. Siting is concerned with the location of a facility. For example, if a company is planning on building a new chemical plant its management may consider the relative merits of sites in Texas, Mexico or China. Layout, on the other hand, is to do with…

Plugged Process Piping

Process lines, piping and valves frequently become plugged. If line pluggage is a recurring problem it is best to try and identify ways in which the problem can be prevented from occurring. If that solution is not possible then valves, drains, tees and connections should be designed so that it is possible to remove the pluggage safely and with minimum time and expense.

Prevention of…

Blinds in Process Piping

Further information to do with blinds in process piping is available in the book Plant Design and Operations.

Blinds - also known as blanks or spades - provide positive isolation between sections of a process. The following guidance is provided to do with the location, installation, and use of blinds.

At battery limits in all process, utility, relief,…

Storage Tanks in the Process and Energy Industries

Storage tanks are widely used in the process industries to store liquids that are below their boiling point at atmospheric temperature (some tanks may be insulated and they may have heating or cooling coils to maintain the temperature of the liquid that they are storing). Typically, tanks are either open to the atmosphere or to a system such as a flare or vent header that is at atmospheric…

Contractors in the Process Industries

For further information on this topic, please refer to our ebook Contractors.

Contractors play a vital and increasingly important role in the design, construction, operation and maintenance of process and energy facilities, as can be seen from the chart shown below. It can be seen that, over the last twenty years or so, the number of contractor work hours has increased by about a…

The Fundamentals of Risk


This article discusses risk fundamentals in the process and energy industries.The word 'risk' has a wide range of meanings. In the context of process plant management it can be categorized in one of three ways.

The first type of risk is to do with catastrophic events and serious safety violations. They can also have a major effect on a company's financial performance to the point…

Principles of Process Safety Management

Many of the publications that we offer are to do with the topic of Process Safety Management (PSM), or with related topics such as the offshore Safety and Environmental Management System (SEMS) and Safety Cases. An overview of the topic of Process Safety Management is provided here. Much more detail is available in the books Process Risk and Reliability Management and Offshore Safety…