Georgi Popov - Risk Assessment

Figure 1.2 Prevention through Design. With permission. Hazards Limited.

The Hazard Analysis and Risk Assessment Process is the longest section in the prevention through design standard. First, an outline of the hazard analysis and risk assessment process is given. That is followed by the “how” for each of its elements. The outline follows:

Select a risk assessment matrix

Establish the analysis parameters

Identify the hazards

Consider failure modes

Assess the severity of consequences

Determine occurrence probability

Define initial risk

Select and implement hazard avoidance, elimination, reduction, and control methods

Assess the residual risk

Risk acceptance decision‐making

Document the results

Follow‐up on actions taken

One of the purposes of this book is to present a variety of risk assessment methods and they are described throughout the text. For many hazards, the proper level of acceptable risk can be attained without bringing together complex teams of people. Safety and health professionals and design engineers having the experience and education can reach the proper conclusions on what constitutes acceptable risk. As defined in Z590.3, acceptable risk is:

Acceptable Risk.That risk for which the probability of an incident or exposure occurring and the harm or damage that may result are as low as reasonably practicable (ALARP) in the setting being considered.

ALARP – as low as reasonably practicable –is defined as that level of risk which can be further lowered only by an increase in resource expenditure that is disproportionate in relation to the resulting decrease in risk. (p. 12)

For the more complex risk situations, management should have processes in place to seek the counsel of experienced personnel who are particularly skilled in risk assessment for the category of the situation being considered. More complex risk assessment methods may be necessary in such situations.

Sometimes, for what an individual considers obvious, achieving consensus on acceptable risk levels is still desirable so that buy‐in is obtained for the actions to be taken.

It is suggested that the risk assessment method chosen fits the need. Sometimes, the method need not be complex. Information on a rather simplistic method follows. Its intent is to be illustrative.

Dated March 2020, NIOSH issued eNews Volume 17, Number 11, under the signature of the Director of NIOSH, Dr. John Howard. Its title is Using Science to Assess Workplace Hazards: NIOSH Practices in Occupational Risk Assessment.Content of this eNews follows:

What is Risk Assessment? Do you check for rain before deciding to carry an umbrella? Doing so is an example of risk assessment, which describes a process for answering three basic questions on a particular hazard.

What can happen? (It may rain today.)

How likely will it happen? (The Weather Channel says 70% chance of showers.)

What are the consequences if it happens? (I’ll be soaked without my umbrella.)

The answers provide a foundation for preventing or lessening the threat imposed by the hazard (e.g. carry an umbrella to avoid getting wet if caught in the rain) known as risk management .

One can take the position that NIOSH was overly simplistic. However, if a person follows the procedure outlined in the foregoing, that person has made a risk assessment.

The ANSI/ASSP Z690 Risk Management Standards are the US national standards for applying risk management for occupational safety and health. They are the US adoption of the ISO 31000 Risk Management Standards.

The three ANSI Standards that constitute a set should be of interest to safety generalists who want to become familiar with risk assessment techniques. The ASSP is the secretariat. Comments on the three standards follow:

ANSI/ASSP Z690.1 – 2011: Vocabulary for Risk Management (National Adoption of ISO Guide 73:2009). This standard provides definitions of terms that, the originators hope, will be used in other standards.

ANSI/ASSP Z690.2 – 2011: Risk Management Principles and Guidelines (National Adoption of ISO 31,000:2009). The intent of this standard is to provide a broad‐range primer on risk management systems that could be applied in any type of organization. The requirement for risk assessments is introduced in Section 5.4: Risk Assessment.

ANSI/ASSP Z 690.3 – 2011: Risk Assessment Techniques (National Adoption of IEC/ISO 31,010:2009). For safety generalists who want a ready reference on risk assessment concepts and methods, this standard is worth acquiring. It commences with a 15‐page dissertation on risk assessment concepts and methods. Appendix A, in five pages, provides brief comparisons of 31 risk assessment techniques. Comments on the 31 techniques, covering Overview, Use, Inputs, Process, Strengths, and Limitations, are provided in Annex B which covers 79 pages.

ANSI/ASSP Z 690.3 – 2011, particularly, is a valuable resource. A list of the 31 risk assessment techniques follows. Some could be applied only by experienced safety professionals who had knowledge of system safety concepts and techniques. Other techniques would be used by probabilistic specialists. However, having knowledge of a few of them will serve for a huge percentage of the needs of a safety generalist.

In the Z590.3 standard, this statement is made (p. 23). “As a practical matter, having knowledge of three risk assessment concepts will be sufficient to address most, but not all risk assessment situations” (that safety professions will face). They are Preliminary Hazard Analysis and Risk Assessment; the What‐If/Checklist Analysis Methods; and Failure Mode and Effects Analysis.

This Is a Standard of Major Importance

Because of the breadth of its coverage, ANSI B11.0 – 2020 is of particular importance for machinery safety. Several parts of the standard are duplicated here with permission from B11 Standards Inc. As is said in the Forward,