- 1-1 Engineering Ethics
- 1-2 Myths about Process Safety
- 1-3 Safety Culture
- 1-4 Individual Risk, Societal Risk, and Risk Populations
- 1-5 Voluntary and Involuntary Risk
- 1-6 Safety Metrics
- 1-7 Accident and Loss Statistics
- 1-8 Risk Perception
- 1-9 Risk Tolerance/Acceptance and Risk Matrix
- 1-10 Codes, Standards, and Regulations
- 1-11 Safeguards
- 1-12 The CCPS 20 Elements of Risk-Based Process Safety
- 1-13 Inherently Safer Design
- 1-14 The Worst Chemical Plant Tragedy: Bhopal, India, 1984<sup><a id="ch01fn13_r" href="ch01.xhtml#ch01fn13">13</a></sup>
- 1-15 Overview of Chemical Process Safety
- Suggested Reading
1-2 Myths about Process Safety
A number of myths about process safety have emerged over the years. It is important to understand why these myths are false, as they can lead to disregard for key tenets of process safety.
Myth 1: Process safety costs a lot of money and has a negative impact on the company’s bottom line.
The story of Alcoa presented earlier in this chapter readily dispels Myth 1. Although safety programs do cost money and there may be startup costs, the reduction in costly accidents and the improvements in all business aspects results in even greater cost savings and a net improvement in profits.
Myth 2: Process safety is the same as personal or even laboratory safety.
Figure 1-1 falsifies Myth 2 by illustrating the difference between personal and process safety. Personal safety—which includes laboratory safety—applies to accidents involving individuals, such as slips and falls, cuts, and other injuries. These events tend to have a higher frequency but lower consequences. In contrast, process safety applies to events with a lower frequency but higher consequences. The process safety and personal/lab safety domains are likely to overlap to some extent, as shown in Figure 1-1.
Figure 1.1 Personal safety versus process safety. Personal safety consists of more frequent, but lower consequence incidents. (Source: Dow Chemical Faculty Workshop, June 2017, AICHE.)
Myth 3: Process safety is no more than following rules and regulations.
Myth 3 is falsified by Table 1-3, which shows the hierarchy of safety programs. The hierarchy ranges from level 0 (lowest level) to level 5 (highest level). The safety program must work its way through the levels from the bottom to the top: No levels can be skipped. Thus, level 5 includes all of the levels below it:
Level 0 consists of no safety program and maybe even disdain for safety. Such a program is destined to have continuous accidents, maybe even accidents that are repeated. No improvement is ever achieved.
Level 1 is a safety program that reacts to accidents as they occur. Accidents do result in changes, but only on a reactive basis, rather than the organization taking a proactive stance. Accidents continue to occur, although specific accidents are not likely to be repeated.
Level 2 is a safety program that consists of complying with rules and regulations. Rules and regulations can never be complete, however, and can never handle all situations. Regulations have legal authority and generally set a minimum standard for industrial operations.
Level 3 introduces management systems to assess hazards and provide procedures to manage hazards. A variety of management systems can be used to achieve this level, including job safety assessment (JSA), lock-out/tag-out (LOTO), management of change (MOC), and other means to control hazards during operations. Written management systems provide documentation to train operators and others and to ensure consistency in operating practices.
Table 1-3 Hierarchy of Safety Programs
Highest 5: Adapting: Safety is a core value of the organization and a primary driver for a successful enterprise.
Lowest 0: No safety—maybe even disdain for safety.
Note: The hierarchy must be worked from bottom to top without skipping any levels.
Level 4 uses monitoring to obtain statistics on how well the safety program is performing. The performance monitoring identifies problems and corrects them. For instance, performance monitoring might indicate a large number of ladder incidents, which might be resolved by additional training in ladder safety.
Level 5 is the highest level, at which the safety program is dynamic and adapting. Safety is a core value for everything that is done and the primary driving force for a successful enterprise.
The hierarchy of safety programs shown in Table 1-3 addresses Myth 3, since rules and regulations are only at level 2. Note that the safety program developed at Alcoa was at level 5—the level that most chemical companies must achieve to have an effective safety program.
Myth 4: Process safety is a soft science—no more than hard hats or safety shoes—not engineering science.
Myth 4 is easily falsified by examining the contents of this text—notice the large number of equations. Process safety is based on engineering science and is just as fundamentally rigorous as any other academic courses in chemical engineering, relying heavily on other core concepts such as mass and energy balances, thermodynamics, fluid flow, and reaction engineering, among others.
Myth 5: Process safety applies only to the petrochemical industry.
Myth 5 is falsified by realizing that all companies require process safety, including warehouses, foundries, food processing, power plants, and so forth. For example, a leading ice cream manufacturer has a process safety vice president due to the large quantities of ammonia used in refrigeration.
Myth 6: Industry should train graduates in process safety; this topic should not be a part of the undergraduate engineering curriculum.
Myth 6, which deals with the training of professionals in safety, was debunked long ago. As early as 1918, L. DeBlois, Dupont Safety Manager, stated:
[S]safety engineering, with its interests in design, equipment, organization, supervision, and education … bears as well a very definite and important relation to all other branches of engineering. This relation is so close, and its need so urgent, that I am convinced that some instruction in the fundamentals of safety engineering should be given a place in the training of every young engineer. He should be taught to think in terms of safety as he now thinks in terms of efficiency. Conservation of life should surely not be rated below the conservation of energy. Yet, few of our technical schools and universities offer instruction in this subject, and the graduates go out to their profession with only vague surmises on “what all this talk on safety is about.”
Companies that hire chemical engineering graduates believe that including process safety in the undergraduate curriculum has enormous added-value, particularly in helping companies achieve level 5 in the safety hierarchy (see Table 1-3). If a graduate is hired by a smaller company, it is possible that the undergraduate curriculum is the only place where the individual will receive instruction in process safety topics. All chemical engineering undergraduates need process safety knowledge, whether they work for major chemical companies, refineries, small chemical companies, government labs and institutes, warehouses, ice cream companies, or even academia.
Myth 7: Process safety does not include product safety.
Myth 7 is falsified by realizing that all companies are responsible for their products, no matter who purchases the product and how it is used. All companies, including chemical companies, must ensure that their products are shipped safely and are used safely by whoever purchases the product.