Rethinking the Safety Triangle

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Preventing injuries and fatalities requires both careful planning and implementation of the plans.In 1931, industrial safety expert H.W. Heinrich proposed a workplace injury theory that is still widely used today – for every 330 workplace incidents, 300 would not result in injury, 29 would result in minor injuries, and one would result in a significant injury or death. For nearly 90 years, Heinrich’s pioneering theory has been accepted as the standard for occupational safety and continues to impact how industry leaders approach workplace safety.

With worker fatalities at an eight-year high, the Campbell Institute recently recommended redesigning Heinrich’s visual representation of injury, called the safety triangle (or pyramid), to better identify the root causes that lead to severe on-the-job injuries and fatalities. The institute, which is part of the National Safety Council, said the existing safety triangle theory is flawed because it treats all minor injuries and near misses as if they have the same potential to result in more serious injuries or fatalities.  The Safety Triangle diverts attention away from the most serious incidents that could lead to deaths, the Campbell Institute said.

“The updated structure is based on identifying the root causes and contextual factors that lead to serious injuries and fatalities on the job,” Industry Safety and Hygiene News said. “Organizations cannot make their workplaces safer by ‘fixing the worker,’ rather they should design work processes to eliminate human error. This makes safety less dependent on employee behavior and more dependent on the safety system.”

For safety experts, understanding the role of the safety triangle theory and proposed changes is essential to designing and implementing a culture of workplace safety. Anyone graduating with a bachelor’s degree in occupational health and safety and entering the occupational safety workforce is expected to be able to implement the latest safety theories in the workplace.

The Safety Triangle Beginnings

Heinrich developed his theory while working at Travelers Insurance Co. in Hartford, CT, as assistant superintendent in the engineering and inspection division. After poring over more than 75,000 injury and illnesses cases and reports, he wrote his landmark book, “Industrial Accident Prevention: A Scientific Approach.”  The safety triangle is depicted with 300 near misses at the bottom, 29 minor injuries in the center, and one major incident at the top.

In the book, Heinrich introduced 10 axioms of industrial safety, also called the domino theory, which states that an injury typically results from a series of factors that are dependent on the preceding factor. Removal of a single element can prevent injuries or accidents, Heinrich theorized.

About 40 years after Heinrich published his study, Frank E. Bird Jr. performed further investigations into occupational hazards and injuries. His follow-up work found a single serious injury for every ten minor injuries, 30 property-damage incidents, and 600 near-miss safety incidents (often referred to as the 1-10-30-600 ratio).

Since the pioneering work by Heinrich and Bird, who was a safety director at a steel company, other occupational safety experts have updated the data.

“Knowing the direct correlation between at-risk behaviors and major injuries can help leaders reduce mishaps in their organizations,” Kent H. Shepherd said in “The Evolution of Workplace Safety.”

At the same time, many safety experts have refuted the theories, saying they are not entirely accurate and may be misleading.

James Howe, a former assistant director of health and safety for the United Auto Workers, told Safety and Health Magazine that some companies with low injury rates had some catastrophic incidents in the past decade.

“The pyramid theory has really done a disservice to the safety profession,” he said, “because it has misled people running safety programs into thinking that if they work on minor incidents, major incidents will go away. And many, many companies are aware that that is not the case.”

Campbell Institute Recommendations

In the past 20 years, the U.S. has made steady gains in workplace safety, with the incident rates dropping from 8.5 incidents per 200,000 working hours in 1993 to 3.0 per 200,000 hours in 2016. However, worker fatalities are at an eight-year high with 5,190 people dying in 2016, according to the most recent data available.

In developing its recommendations to revamp the safety triangle, the Campbell Institute said safety professionals must focus on precursors that have the potential to cause serious injuries or deaths. Some strategies to prevent such incidents include identifying the precursors, educating employees about them, and eliminating the possibility for such events.

“In order to prevent serious injuries and fatalities (SIF) from occurring, many organizations have realized that they cannot look at the entire triangle, at least not in the way Heinrich originally conceived of it,” Campbell Institute researchers said. “Instead, they have to isolate that part of the triangle with the potential for SIF and prevent those incidents from occurring.”

Implementing Organizational Safety Changes

The Campbell Institute also said that SIF prevention requires both careful planning and implementation of the plans. One of the leading factors that determine success is having a supportive organizational leadership that allows safety professionals to implement improvements, the institute said. When occupational safety specialists work together with executive leadership, positive safety changes can happen.

An entire organization, from the top down, must be willing to buy into safety planning and positive safety culture. Safety experts who graduate from Eastern Kentucky University’s (EKUs) Online Bachelor of Science in Occupational Safety (BSOS) program learn about the positive influence that safety plays in workplace culture. Students enrolled in the university’s online health and safety courses learn how to enact workplace changes for better safety performance.

About Eastern Kentucky University’s Online Bachelor of Science In Occupational Safety

At EKU, students learn about advanced-level safety solutions that prepare them for work in the public and private sectors. The university’s faculty are safety industry leaders who are committed to helping students succeed.

The online coursework allows students to continue their home and career responsibilities while earning an advanced degree. The university’s internship agreements and the career development and placement office help students achieve their professional goals. For more information, contact EKU now. 

Recommended Reading

Changing Workplace Culture For Improved Safety Performance

4 Security Management Jobs That Could Be Perfect for You

4 Keys to Avoiding Workplace Accidents


Serious Injury and Fatality Prevention: Perspectives and Practices: Campbell Institute

Worker fatalities at 8-year high: Industry Safety and Hygiene News

Reviewing Heinrich Dislodging Two Myths From the Practice of Safety: Professional Safety

The Campbell Institute: Eliminating higher-potential events: Safety and Health

The Evolution of Workplace Safety: U.S. Army

Examining the foundation: Safety and Health

The Next Level of Workplace Safety: National Safety Council