Course 162 Accident Investigation: Basic

Analyzing the Facts

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This shows how the direct cause of injury and surface causes result from deeper root causes.
Click to enlarge.

Step 5: Conduct Cause Analysis

You've completed the initial step of the accident analysis by gathering information and using it to break the accident down into an accurate sequence of events. You have a good mental picture of what happened. Now it's time to continue the analysis process by completing each of the following three phases of analysis to determine what caused those events. This module will introduce us to three phases of analysis:

  • Phase 1: Injury Analysis: It's important to understand, we're not analyzing the accident in this phase: we are analyzing precisely what happened during the accident event to identify the type of harmful energy involved (electrical, mechanical, thermal, etc.) and how the harmful transfer of this energy (an action) caused the injury or illness. Remember, the outcome of the accident process is an injury or illness.
  • Phase 2: Surface Cause Analysis: In this next phase in the analysis process, you determine how the hazardous conditions and unsafe behaviors described in each of the events interact to produce the accident. The hazardous conditions and unsafe behaviors uncovered are the surface causes for the accident and give clues that point to possible system weaknesses.
  • Phase 3: Root Cause Analysis: During this phase of the analysis process, you're analyzing the weaknesses in the Safety Management System (SMS) that contributed to the accident. You can usually uncover weaknesses related to inadequate safety policies, programs, plans, processes, or procedures. Root causes always pre-exist surface causes and may function through poor component design to allow, promote, encourage, or even require systems that result in hazardous conditions and unsafe behaviors.

We'll cover each of these three phases of analysis in more detail in the next few sections.

1. In which phase of cause analysis, do we want to know what system weaknesses contributed to the accident?

a. Injury cause analysis
b. Surface cause analysis
c. Root cause analysis
d. Stem cause analysis

Phase 1: Injury Analysis

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What is the direct cause of this injury?

It's important to understand all injuries to workers are caused by one thing: the harmful transfer of energy. Let's take a look at some examples that illustrate this important principle.

  • If a harsh acid splashes on your face, you may suffer a chemical burn because your skin has been exposed to a chemical form of energy that destroys tissue. In this instance, the direct cause of the injury is a harmful chemical reaction. The related surface causes might be the acidic nature of the chemical (condition) and working without proper face protection (unsafe behavior).
  • If your workload is too strenuous, force requirements on your body may cause a muscle strain. Here, the direct cause of injury is a harmful level of kinetic energy (energy resulting from motion), causing injury to muscle tissue. A related surface cause of the accident might be fatigue (hazardous condition) or improper lifting techniques (unsafe behavior).

In the next section, we'll take a closer look at each of the types of energy that might cause injury.

Image of a helmet on the floor and another image of a workers lower legs climbing a step ladder
Direct and Surface Causes
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The important point to remember here is the "direct cause" of the injury is not the same as the "surface cause" of the accident event.

  • The direct cause of injury is the harmful transfer of energy as a consequence of your exposure to that energy. The direct result of the harmful energy transfer is injury. The cause is the harmful transfer of energy. The effect is the injury.
  • The surface cause of the accident is the condition and behavior that interacts in a way that results in the harmful transfer of energy. The interaction of the condition and behavior is the cause. The effect is the harmful transfer of energy.

2. The direct cause of injury or illness is always _____.

a. the result of a general lack of common sense
b. the harmful transfer of energy
c. a hazardous condition
d. an unsafe behavior

Phase 2: Surface Cause Analysis

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Two categories of surface causes: conditions and behaviors that cause exposure.
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In the last module, you learned that each event in our sequence will include an actor and an action that may have contributed to the accident. Once we have identified the actors and actions in the sequence of steps, our next job is to analyze each event to determine the surface causes for the accident.

What are Surface Causes?

The surface causes of accidents are those hazardous conditions and unsafe or inappropriate behaviors within the sequence of events that have directly caused or contributed in some way to the accident. It's important to understand that surface causes describe unique conditions or individual behaviors.

A hazardous condition is characterized by the following:

  • a unique tool, piece of equipment, or machinery, etc., that is not properly guarded or somehow defective
  • an employee's "state of being" such as fatigue or being distracted
  • may also be a unique defect in a process, procedure or practice
  • may exist at any level of the organization
  • is the result of deeper root causes

Unsafe or Inappropriate Behaviors are characterized by:

  • taking an intentional/unintentional action that is unsafe or failure to take an action that is safe
  • a unique performance error in a process, procedure or practice
  • may exist at any level of the organization
  • are the result of deeper root causes

It's important to know most hazardous conditions in the workplace are the result of the unsafe or inappropriate behaviors that produced them.

3. Which of the following would be considered a surface cause for an accident?

a. Inadequate safety inspections
b. A lack of safety supervision and leadership
c. A defective piece of equipment
d. Inadequate safety training program
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Two categories of root causes: Performance and deeper Design root causes.
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Phase 3: Root Cause Analysis

The root causes for accidents are the underlying SMS weaknesses that consist of thousands of variables, any number of which can somehow contribute to the surface causes of accidents. This level of investigation is also called "common cause" analysis (in quality terms) because you're identifying a system component that may contribute to common conditions and behaviors that exist or occur throughout the company. These weaknesses can take two forms.

  • SMS Design Root Causes: Inadequate design of one or more components of the safety management system. The design of safety management system policies, plans, programs, processes, procedures and practices is very important to make sure appropriate conditions, activities, behaviors, and practices occur consistently throughout the workplace. Design root causes describe the "condition" of the SMS, and ultimately, they contribute to most accidents.
  • SMS Performance Root Causes: Inadequate implementation of one or more components of the SMS. After each SMS component is designed, it must be effectively carried out or implemented. Performance root causes describe the "behavior" of the SMS. You may design an effective safety plan, yet suffer failure because it wasn't implemented properly. On the other hand, if you effectively implement a poorly designed component, you'll get the same results: inadequate system performance.

Ultimately, for the SMS to be effective, both the design and implementation must be effective.

4. Which of the following is an example of an safety management system (SMS) design root cause?

a. Failure of employees to respond properly when fire alarms sound
b. A failure to assemble properly during a fire drill
c. No written emergency action plan or fire prevention plan
d. Employees are unfamiliar with how to use fire extinguishers

Assume the SMS Failed

When conducting an accident investigation, a basic assumption should be that somehow the SMS has failed. The investigation will either verify this assumption, or prove it wrong. Most of the time, it will be verified. Why is that? Most accidents in the workplace result from unsafe work behaviors.

  • unsafe behaviors are the primary surface cause for the vast majority of all workplace accidents;
  • hazardous conditions are the primary surface cause for a small percentage of workplace accidents; and
  • uncontrollable (unknowable) "acts of God" account for the remaining very small percentage.

These statistics imply that, because SMS weaknesses contribute in some way to workplace hazardous conditions and unsafe behaviors, those weaknesses are ultimately responsible for almost all workplace accidents. So, the basic assumption should be that, ultimately, most accidents are the result of SMS weaknesses, not unsafe behaviors or hazardous conditions.

To effectively fulfill your responsibilities as an accident investigator, you must not close the investigation until these root causes and solutions have been identified.

5. Accident investigators should assume that most accidents are caused by _____.

a. unsafe behaviors
b. hazardous conditions
c. system weaknesses
d. lack of common sense

Step 6: Determine Solutions

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Corrective actions and system improvements can prevent the accident.

In this step we propose recommendations that include effective immediate corrective actions and system improvements that, when applied effectively, can transform the investigation into valuable "proactive" process that helps to prevent future injuries. It's important to divide your recommendations into the categories below:

  1. Immediate or short-term corrective actions to eliminate or reduce the hazardous conditions and/or unsafe behaviors related to the accident.
  2. Long-term system improvements to create or revise existing safety policies, programs, plans, processes, procedures and practices identified as missing or inadequate in the investigation.

Some employers may assign the responsibility for making recommendations to safety directors or other managers. However, you, as the accident investigator, may be required to take on this very important responsibility. Consequently, it's a good idea to know where to start, and how to write strong recommendations.

One tip up front: If you find the responsibility is yours, be sure to get the help of experts if you are unsure how to proceed. OSHA consultants, other safety professionals or your workers' compensation insurer can be a great source for help.

6. An effective recommendation will include _____ corrective actions and _____ system improvements.

a. common sense; engineering
b. feasible; reasonable
c. primarily; additional
d. short-term; long-term

The Hierarchy of Controls

Chart depicting the hierarchy of controls
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Safety professionals recognize several primary control strategies to eliminate or reduce health hazards and employee exposure to those hazards. These basic control strategies are further organized into a "Hierarchy of Controls." ANSI/ASSP Z10-2012, Occupational Health and Safety Management Systems, encourages employers to use the following hierarchy of hazard controls when making recommendations for corrective actions and system improvements:

The first three strategies attempt to control hazards and the bottom three strategies try to change exposure to hazards. Controlling hazards is always preferred to controlling behavior, and that's why these strategies are at the top of the hierarchy.

  1. Elimination - completely removes the source of the hazard. This strategy totally eliminates the hazard from the workplace. Elimination is the top priority for controlling hazards.
  2. Substitution - reduces the hazard. This strategy should be used if it is not feasible to eliminate the hazard. The idea is to reduce the severity of a hazard by replacing it.
  3. Engineering controls - isolate the hazard through design. This strategy involves the design or redesign of tools, equipment, machinery and facilities so that hazardous chemicals are not needed or that exposure to those hazardous chemicals are not possible. Examples include enclosing work processes or installing local ventilation systems.

The remaining strategies attempt to control employee behaviors to eliminate or reduce exposure to existing health hazards when hazard controls are not adequate. Naturally it's more difficult to control behaviors than hazards because we're dealing with human behavior.

  1. Warnings - raise awareness through by using signs, alarms, signals, labels, placards, cones, and other methods. For example, a warning sign might be used to keep workers from entering a confined space.
  2. Work practice controls - eliminate or reduce exposure to hazards by developing and implementing effective policies, procedures, and rules that mandate safe work practices. This strategy really gets to the root causes by making recommendations to improve system weaknesses.
  3. Personal Protective Equipment (PPE) - eliminates/reduces exposure through personal barriers that prevent exposure. This strategy is generally used in conjunction with the other strategies. When effective elimination, substitution and engineering controls are not feasible appropriate personal protective equipment and clothing may be required. To be effective, PPE must be individually selected, fitted, properly worn, and replaced.

7. Which of the following control measures is considered the highest priority in the "Hierarchy of Controls?"

a. Administrative controls
b. Engineering controls
c. Elimination
d. Personal protective equipment
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To sell safety, emphasize the benefits!

"Selling" Safety

You must "sell" management on the benefits of approving your recommendations. To most effectively do that, emphasize the bottom line - how they will benefit financially. Educate management on the direct and indirect accident cost savings realized if your recommendations are approved.

Direct and Indirect Cost Savings: Indirect costs can be over four times direct costs when an accident occurs. To help management understand the bottom-line financial benefits from approving recommendations, emphasize the financial benefits. The most common way of doing this is to estimate the direct and indirect cost savings.

  • Direct costs include workers' compensation payments, medical expenses, and costs for legal services.
  • Indirect costs include training replacement employees, accident investigation and implementation of corrective measures, lost productivity, repairs of damaged equipment and property, and costs associated with lower employee morale and absenteeism.

OSHA's Safety Pays software is an excellent tool that estimates direct and indirect accident costs. It also calculates the business volume required to cover those costs. The data is based on 52,000 lost-time claims submitted to a major workers compensation insurance carrier.

Provide Options

Another good recommendation strategy is to provide the decision-maker with alternative corrective actions. This will increase the probability that the decision-maker will choose one of the alternatives. Your options might follow the logic below:

  1. First option -- If we had all the money we needed, what could we do? Eliminate the hazard with primarily engineering controls. Additional administrative controls if required.
  2. Second option -- If we have limited funds, what would we do. Eliminate the hazard with primarily administrative controls. Engineering controls if required.
  3. Third option -- If we don't have any money, what can we do? Reduce exposure to the hazard with administrative controls and/or PPE.

8. What should you emphasize to improve the chances of getting your recommendations for corrective actions and system improvements approved by management?

a. Improvement in processes and procedures
b. Increased employee morale and discipline
c. Direct and indirect cost savings
d. Protection from OSHA inspections
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Develop an effective accident investigation report form.

Step 7: Write the Report

Now that you have accurately assessed and analyzed the facts related to the accident and developed effective corrective actions and system improvements, you must report your findings to those who have the authority to take action.

The Accident Report Form

One of the most common reasons an accident investigation might fail to fulfill its intended purpose of helping to eliminate similar accidents, is that the report form is poorly designed. They actually make it difficult to get beyond identification of only surface causes: root causes are often ignored. Consequently, system improvements are not recommended.

Let's look at one format that is designed to emphasize root cause analysis. Take a look at a sample accident report. This is a report format similar to that used by OSHA accident investigators in conducting workplace accident investigations, but it goes further. This form includes the identification of safety management system weaknesses and recommended improvements. You may want to print this form while we discuss the various sections.

Section I. Background

This section contains background information that answers questions about who the victim is, and the time, date, location of the accident, as well as other necessary details. Make sure you obtain all of this information for possible later reference.

Section II. Description of the Accident

This section presents a descriptive narrative of the events leading up to, including and immediately after the accident. It's important that the narrative paint a vivid "word picture" so that someone unfamiliar with the accident can clearly see what happened.

Click on the button to see a sample description of an accident.

Description of the Accident
  1. Employee #1 returned to work at 12:30 PM after lunch to continue laying irrigation pipes.
  2. At approximately 12:45 PM employee #1 began dumping accumulated sand from an irrigation mainline pipe.
  3. Employee #1 oriented the pipe vertically and it contacted a high voltage power line directly over the work area.
  4. Employee #2 heard a "zap" and turned to see the mainline pipe falling and employee #1 falling into an irrigation ditch.
  5. Employee #2 ran to employee #1 and pulled him from the irrigation ditch, laid him on his back and ran about 600 ft to his truck and placed a call for help on his mobile phone.
  6. Employee #2 than ran back to find employee #1 had fallen back into the ditch.
  7. Employee #2 jumped back into the ditch and held employee #1 out of the water until help arrived.
  8. Two other ranch employees arrived and assisted employee #2 in getting employee #1 out of the ditch.
  9. Approximately one minute later, paramedics arrived and began to administer CPR on employee #1.
  10. They also used a heart defibrillation machine in an attempt to stabilize employee #1' s heart beat.
  11. At approximately 1:10 PM an ambulance arrived and transported employee #1 to the hospital where he was pronounced dead at 1:30 PM.

9. What is one of the most common reasons accident reports fail to achieve their intended purpose?

a. Too many recommendations
b. Poorly-written accident report forms
c. Recommendations are not reasonable
d. Failure to submit the report
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Present your findings and recommendations in a professional manner.

The Accident Report Form (Continued)

Section III. Findings

The findings section describes the hazardous conditions, unsafe behaviors and the system weaknesses your analysis has uncovered. Each description of a surface or root cause will also include justification for the finding. The justification will explain how you came to your conclusion.

Unfortunately, the most common failure found in accident reports is they address only surface causes. Consequently, similar accidents recur. These report forms may have a format that "forces" the investigator to list only surface causes for accidents. The form does not "report" the system weaknesses associated with each surface cause. Consequently, the investigator believes the job is done without ferreting out the system weaknesses representing the root causes.

Other forms may actually require the investigator to indicate the status of employee negligence. Now, how can the accident investigator assure an interviewee or any other employee that the purpose of the analysis process is to "fix the system -- not the blame," when the report form shouts "negligent"?

To complete this section, just state the facts: The hazardous conditions, unsafe behaviors, practices, and inadequate or missing programs, policies, plans, processes and procedures that produced them. Be sure to write complete descriptive sentences. Not short cryptic phrases.

Take a look at this sample Section III: Findings and Justifications.

Section IV. Recommendations

If root causes are not addressed properly in Section III of the report, it is doubtful recommendations in this section will include improving system inadequacies. Effective recommendations will describe ways to eliminate or reduce both surface and root causes. They will also detail estimated costs involved with implementing corrective actions. Let's take a closer look at effective recommendation writing. Review this sample Section IV. Recommendations.

Section V. Summary

This section contains a brief review of the causes of the accident and recommendations for corrective actions. In your review, it's important to include language that contrasts the costs of the accident with the benefits derived from investing in corrective actions. Including bottom-line information will ensure that your recommendation will be understood and appreciated by management. Remember, it's never appropriate for the accident investigator to recommend disciplinary action. Disciplinary action should be considered only by managers and only after very careful consideration of all of the facts. By the way, if system weaknesses that contributed to the accident are identified, discipline is likely unnecessary.

Open document: The accident investigation report should be considered an open document until all recommendations have been addressed.

Well, that winds up the final module in this course. Answer the final question and check your answers. Then, head over to the final 10-question exam.

10. Which of the following is not appropriate in an accident investigation report?

a. An estimate of the costs of system improvements
b. Assignment of corrective action responsibilities
c. Recommended disciplinary action
d. Timelines for corrective action and system improvements

Check your Work

Click on the "Check Quiz Answers" button to grade your quiz and see your score. You will receive a message if you forgot to answer one of the questions. After clicking the button, the questions you missed will be listed below. You can correct any missed questions and check your answers again.

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