05/02/2026
Understanding the Safety Triangle: A Foundation or a Flaw?
At 2020 Safety Training, we believe that understanding the history of Occupational Safety and Health (OSH) is key to building a safer future. Today, we’re looking at one of the most famous models in the industry: The Safety Triangle.
The Origins: How It Was Made
The concept was pioneered by Herbert W. Heinrich in his 1931 book, Industrial Accident Prevention. After analysing 75,000 insurance reports, Heinrich proposed a statistical relationship: for every 1 major injury, there are 29 minor injuries and 300 no-injury accidents.
In 1966, Frank E. Bird expanded this research by analysing over 1.7 million reports, updating the ratio to include "Near Misses" and "Unsafe Acts" at the base. The core mindset is proactive: by managing the high-volume risks at the bottom, you prevent the rare catastrophe at the top.
The Debate: Arguments For and Against
While the Triangle is a staple in safety training, its modern applicability is often debated among OSH professionals.
Arguments FOR its use:
Encourages Reporting: It highlights that "Near Misses" are free lessons. It empowers workers to speak up before someone gets hurt.
Simple Visualization: It provides a clear, easy-to-understand framework for employees at all levels to visualize how small behaviors link to major consequences.
Focus on Leading Indicators: By tracking "Unsafe Acts," companies can shift from reactive to proactive safety management.
Arguments AGAINST its use:
The "Zero Harm" Trap: Critics argue that focusing too much on the base can lead to underreporting. Workers may hide minor injuries to keep the "triangle" looking healthy.
Ignoring SIF Potential: Not all near misses are equal. Some minor incidents have "Serious Injury or Fatality" (SIF) potential, while others do not. Critics argue the model treats all low-level events with equal weight.
Individual vs. System Blame: Heinrich’s original model blamed 88% of accidents on "unsafe acts" by individuals. Modern safety science (like the Bowtie Method) focuses more on management systems and failed barriers.
OSH Applicability Today
Is the Safety Triangle still relevant? We say yes—but only as part of a larger toolkit. At 2020 Safety Training, we teach that while managing high-frequency behaviour's is important, businesses must also use tools like Bowtie Risk Assessments to identify the specific barriers that prevent catastrophes as well as understanding the causes of slips, trips and falls.
Don't just manage the numbers; manage the risks. Whether you are working toward your NVQ Level 6 Diploma or just starting your safety journey, we are here to help you navigate these complex theories with practical, expert support.
Ready to elevate your safety culture? Visit us at: 2020safetytraining.co.uk